The human body is constituted by different systems: all these systems work together regularly without any hindrance. The human body is made up of seven basic dhatus i.e. rasa, rakta, mansa, meda, asthi, majja and sukra. A number of changes occur in the human body during the whole life span, the homeostasis of doshas is known as health; imbalance in the doshic state may lead to the disease: shariram vyadhi mandira means the body is the seat of diseases.
The aim of Ayurveda is to preserve the health of a healthy individual and to cure the diseases of a diseased person. There is a major role of marma therapy and yoga along with Ayurveda to fulfill the above-mentioned goal. The whole world is requiring marma therapy and yoga as a weapon to combat the diseases of modern life. Marma therapy and yoga is practiced by many people for achieving the healthy state of life. A number of incurable diseases are treated with marma therapy and yogic practices.
Effect of self- marma therapy and yogic practices on digestive system: -
Digestive power of the body improves by regular self-marma therapy and yogic practices. The essential substances are supplied to the body regularly by absorbing these substances through absorption of the food material by the intestine. Metabolism of food takes place in the liver. Excessive available nutrients are deposited in different parts of the body. During necessity the body itself utilizes these nutrients.
The following effects are seen on the digestive system by marma therapy and yogic practices:
It maintains the digestive power healthier by stimulating all organs of Gastro Intestine Tract.
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It improves the digestive function of the body.
Increases the appetite by proper digestion of food.
Improves the function of intestine, so the intestine takes out the harmful substances properly.
Improves the peristaltic movement of Gastro Intestine Tract and relieves constipation, loss of appetite and hyperacidity.
By proper digestion of food the body gets proper nutrients and it also improves the working capacity of the body.
mportant organs of the digestive system—
Tongue
Salivary glands
Oesophagus
Stomach
Duodenum
Small Intestine
Appendix
Large Intestine
Rectum
Liver
Pancreas
Main Diseases of the Digestive System:
Hyperacidity
Useful in digestive system diseases:
1. Asana: - Vajrasana, supta vajrasana, ardhamatsyendrasana, paschimottana -sana. mayurasana, pavanmuktasana. katichakrasana, sarpasana. dhanurasana, sarvangasana, trikonasana, akarnadhanurasana, surya-namaskara.
Pranayama: - Nadi Shodhana, bhastrika.
Bandha: - Moola bandha, uddiyana bandha, etc.
Mudra: - Ashwini mudra, tadagi mudra, maha mudra etc.
Kriya:- Kunjala, vasti, sankhaprakshalana, Nauli, vastradhauti, agnisara etc.
Dhyana
Marma therapy:- Guda, nabhi, kurpara and indravasti.
Effect of self-marma therapy and yogic practices on blood circulatory system:
During yogic practices heart and circulatory system play an important role. It is a well known fact that any work is not possible without energy. Oxygen and nutrients are generated in the muscles during yogic practices. So at the time of yogic practices the heart rate and arterial blood circulation also increases. By this process blood pressure also increases. Due to increased blood circulation the lungs also work rapidly Body temperature increases due to different biochemical reactions in the muscles. Increased body temperature due to exercise is maintainted by sweat glands; they produce more sweat. Many excretory substances are also excreted through the sweat. Following effects take place on the circulatory system, during yogic practices.........
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Regular self- marma therapy and yogic practices may produce some changes in the body. The working capacity of the heart improves by regular self- marma therapy and yogic practices. The heart pumps good amount of pure blood into the circulation so the oxygen and other nutrients are readily available for better physiological activities of the body.
Regular self- marma therapy and yogic practices may lead to bradycardia. It provides better effect on the heart and the circulatory system. It improves the working capacity of the heart. During hard work the circulatory system gives better performance.
Regular self- marma therapy and yogic practices may lead to a number of biochemical changes in the blood. It increases the oxygen carrying capacity of the blood. Excretory metabolites and substances are taken away rapidly. So the concentration of excretory metabolites remains in lower level. Blood cholesterol decreases and the chances of heart attack are few in this condition.
Regular self- marma therapy and yogic practices may prevent the heart diseases. Patients of heart diseases may prefer high yogic practices like Kundalini jagaran and achieving Samadhi. By these practices the heart becomes healthier and strong.
By regular self- marma therapy and yogic practices the blood cells count increases. So the blood carrying capacity, diseaseresistant capacity and immunity improves.
The general body build and outlook become healthy. There is marked improvement in body resistance power.
Important organs of blood circulatory (cardio vascular) system: -
1. Arteries
2. Veins
3. Heart
Important diseases of blood circulatory (cardio vascular) system:-
1. Hypertension
2. Congenital heart diseases
3. Cardiac vascular diseases
4. Coronary artery diseases
5. Pericarditis
Useful in blood circulatory (cardio vascular) diseases: -
1. Asana:- Sheershasana, sarvangasana, shavasana, naukasana, halasana, karnapidasana etc.
2. Pranayama:- Bhastrika pranayama, nadi shodhana
pranayama, anuloma-viloma pranayama, etc.
3. Mudra:- Tnmani mudra, shambhavi mudra etc.
4. Bandha:- Uddiyana bandha, mula bandha etc.
5. Satakriya:- Agnisara, vastra dhauti, kunjala etc.
6. Dhyana
7. Marma therapy:- Talahridaya, nabhi, hridaya.
Contra-indication of yogic practices in different blood circutatory/ cardio-vascular diseases:-
In the following conditions yogic practices should not be done
1. Congenital heart diseases.
2. Cardiac failure
3. Acute pericarditis
4. Infective diseases of heart and blood vessels.
But there is no any contra-indication of marma therapy in abovementioned conditions. In these conditions marma therapy does not hurt the site of lesion. It gives positive effect on the affected site. One can perform the marma therapy at any stage of disease
Effect of self- marma therapy and yogic practices on respiratory system:
Every physical activity needs energy. Oxygen is necessary for the energy generation from the food material. Any exercise or hard work needs more oxygen, and for better oxygenation lung functions get affected. During yogic practices the respiration rate gets increased. In the lung, exchange of oxygen and carbon dioxide takes place at the cellular level in a better way. Oxygen absorption increases and removal of carbon dioxide becomes more pronounced. During this exchange energy is generated so the body temperature and respiratory rate may be raised. Regular self- marma therapy and yogic practices may affect the body and mind. The following effects are noted on the respiratory system during yogic practices.
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Regular self- marma therapy and yogic practices enhances the working capacity of the respiratory system especially the lungs and bronchial tree. Initially there is marked increase in the respiration rate during exercise but in the long run the respiratory rate does not get much affected even after vigorous yogic practice.
By regular self- marma therapy and yogic practices lung capacity increases. Vital capacity and tidal volume gets positiveresponse.
Regular self- marma therapy and yogic practices improve the function of the muscles supporting the respiration.
Due to regular self- marma therapy and yogic practices especially pranayama oxygen consumption gets lower, so the respiration rate gets more slowed down. One can perform all vigorous activities without increasing the respiratory rate.
Important organs of respiratory system: -
1. Nose 2. Trachea
3. Lungs
4. Thoracic muscles
5. Diaphragm
Important diseases of respiratory system: -
1. Rhinitis
2. Cough
3. Bronchitis
4. Pneumonitis
5. Tuberculosis
6. Bronchial Asthma
Useful in diseases of respiratory system:-
1. Asana: - Yoga mudra, singhasana, akarna dhanurasana, shavasana, paschimottanasana, pavanmuktasana, naukasana, sarvangasana, halasana, karnapidasana etc.
2. Pranayama: - Nadi shodhan pranayam, bhastrika pranayama, suryabhedan pranayana etc.
3. Satakriya: - Jalaneti, sutra-neti, kapala-bhati, kunjal-kriya, vastra-dhauti, nauli etc.
4. Bandha: - Uddiyana bandha, jalandhara bandha etc.
5. Mudra: - Viparita karani, mahamudra
. 6. Dhyana
7. Marma therapy: - Marma of head and neck and thorax.
Contra-indication of yogic practices in different respiratory diseases:-
In following diseases yogic practice should not be done
1. Acute infective diseases of respiratory system
2. Acute pneumonitis.
3. Haemoptysis.
4. Tuberculosis and complications.
5. Epistaxis.
6. Acute Rhinitis & Sinusitis.
But there is no any contra-indication of marma therapy in abovementioned conditions. In these conditions marma therapy does not hurt the site of lesion. It gives positive effect on the affected site. One can perform marma therapy at any stage of disease.
Effect of self-marma therapy and yogic practices on excretory system:-
Skin, kidneys and large intestine are the main excretory organs of the human body. Regular self- marma therapy and yogic practices give positive impact on these organs. Self- marma therapy and yogicm practices affect these organs in the following ways
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During exercise the heart rate and pulmonary function improve. They work more efficiently. Consumption of oxygen increases and more carbon dioxide gets excreted. This removes a number of body ailments.
Sweat glands in the skin produces more sweat and due to excessive perspiration more metabolites are excreted through the sweat glands. It keeps the blood pure.
During self- marma therapy and yogic practices due to increased blood circulation in the brain, heart, kidneys and liver, the working capacity of these organs increases. The body becomes healthier. The kidneys play an important role in urine formation and excretion of metabolites through urine. Kidneys are the main blood filters. The liver plays an important role in the digestion of foot. Bile formation takes place in the liver. From the liver bile comes into the gall bladder, shrinks, and the whole bile comes into the duodenum. Bile is important for the digestion of fat in many ways. But it contains many other metabolites, pigments, salts and excretory substances that also reach in the intestine and is evacuated through the faecal material and urine.
By regular self-marma therapy and yogic practices the working capacity of the organs of digestive system improves. Smooth muscles of gastro intestinal tract become stronger and digestion power improves. Excretion of excretory substances takes place in a better way. Yogic practices play an important role to improve the functioning of all excretory organs. Important organs of urine excretory system: -
1. Kidneys
2. Ureters
3. Urinary bladder
4. Urethra
Important diseases of urine excretory system: -
1. Nephritis
2. Ureteritis
3. Cystitis
4. Urolithiasis
5. Haematuria
6. Oilgouria and anuria
7. Prostatic enlargement
Useful yogic practices in urine excretory system: -
1. Asana: - Ardhamatsyendrasana, matsyendrasana, ustrasana, trikonasana, paschimottanasana, naukasana, pavanmuktasana, supta-katichakrasana, kati chakrasana, bhuganagasana, mayurasana, dhanurasana, halasana, bhunamanasana, hastapadangysthasana, surya namaskara etc.
2. Pranayama: - Nadishodhana pranayana, bhastrika pranayana etc.
3. Bandha: - Mula bandha, uddiyana
4. Mudra: - Ashwinimudra, tagadimudra, mahamudra, bajrali mudra etc.
5. Kriya: - Vasti, nauli, sankha prakshalana, agnisarakriya, kunjala etc.
6. Dhyana
7. Marma therapy: - Parsvasandhi, guda, vasti, nabhi and marmas of lower extremity.
Contra-indication of yogic practices in different diseases of urine excretory system: -
In the following urine excretory system diseases yogic practices should not be done.
1. Acute uraemia/ azotemia
2. Urolithiasis
3. Hematuria
4. Acute urinary tract infection
5. Malignant growth of urinary system.
But there is no any contra-indication of marma therapy in abovementioned conditions. In these conditions marma therapy does not hurt the site of lesion. It gives positive effect on the affected site. One can perform the marma therapy at any stage of disease.
Effect of marma therapy and yogic practices on endocrine and exocrine glands:
In the following urine excretory system diseases yogic practices should not be done.
1. Acute uraemia/ azotemia
2. Urolithiasis
3. Hematuria
4. Acute urinary tract infection
5. Malignant growth of urinary system.
But there is no any contra-indication of marma therapy in abovementioned conditions. In these conditions marma therapy does not hurt the site of lesion. It gives positive effect on the affected site. One can perform the marma therapy at any stage of disease.
Effect of marma therapy and yogic practices on endocrine and exocrine glands: -
There are two types of glands
1. Endocrine gland
2. Exocrine gland
Those glands are endocrine which are ductless. Secretion of these glands directly enters into the blood circulation........
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Pituitary, thyroid, parathyroid thymus and adrenals are the main endocrine glands. Pancreas, ovary and testicle are combined glands. Some of these secretes enzymes, ova and sperms are transported into intestine, uterus and urethra. Salivary glands, sweat glands and glands situated in the stomach and intestine secrete their secretions.
In reference to sweat glands, any exercise increases the excessive sweating. Yogic practices increase the blood circulation of the glands. Due to increased blood circulation, the function of these glandsimproves. So the body immunity and secretion of these glands affect the function of many organs.
By regular yogic practices the function of these glands can be affected. In the healthy individual yogic practices may activate the function of these glands. Health promotion is possible by activating the endocrine and exocrine glands.
Regular yogic practices and marma therapy improve the
function of glands.
Glands secrete good amount of hormone.
The quality and composition of hormones becomes more balanced.
It improves the body immunity and decaying/ageing process can be delayed.
Important Glands are-
1. Pituitary gland
2. Thyroid gland
3. Parathyroid gland
4. Thymus gland
5. Pancreas gland
6. Adrenal glands
Important diseases of endocrine glands:
1. Thyroid swelling
2. Diabetes
3. Infertility
4. Congenital brain and anatomical deformities.
Useful yogic practices in different endocrine gland diseases: -
1. Asana: - Siddhasana, matsyendrasana, yoga mudra, mayurasana, shirshasana, paschimottanasana, pavan muktasana, suptakatichakrasana, trikonasana etc.
2. Pranayama: - Nadi shodhana, bhastrika, bhramari, surya bhedi, dhaauani yukta pranava uchcharana(Japa) etc.
3. Bandha: - Mula bandha, uddiyana bandha, jalandhara bandha, etc.
4. Mudra: - Khechari mudra, shambhavi mudra, ashwini mudra etc.
5. Kriya: - Jalaneti, sutra neti, kunjala, vasti, trataka etc.
6. Dhyana
7. Marma therapy: - Marmas of neck and head, and marmas related to particular endocrine gland.
Contra-indication of yogic practices in different diseases of endocrine system: -
In the following endocrine system diseases yogic practices should not be done.
1. Acute haemorrhagic conditions of endocrine system.
2. Traumatic lesions of endocrine system.
3. Acute endocrine infection.
4. Malignant growth of endocrine system.
But there is no any contra-indication of marma therapy in abovementioned conditions. In these conditions marma therapy does not hurt the site of lesion. It gives positive effect on the affected site. One can perform the marma therapy at any stage of disease.
Friday, May 6, 2011
EXCRETORY SYSTEM
The Human Excretory System
The urinary system is made-up of the kidneys, ureters, bladder, and urethra. The nephron, an evolutionary modification of the nephridium, is the kidney's functional unit. Waste is filtered from the blood and collected as urine in each kidney. Urine leaves the kidneys by ureters, and collects in the bladder. The bladder can distend to store urine that eventually leaves through the urethra
Human excretory system and the details of the kidney. Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The Nephron
The nephron consists of a cup-shaped capsule containing capillaries and the glomerulus, and a long renal tube. Blood flows into the kidney through the renal artery, which branches into capillaries associated with the glomerulus. Arterial pressure causes water and solutes from the blood to filter into the capsule. Fluid flows through the proximal tubule, which include the loop of Henle, and then into the distal tubule. The distal tubule empties into a collecting duct. Fluids and solutes are returned to the capillaries that surround the nephron tubule.
Filtration of the blood in the fine structure of the kidneys. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The nephron has three functions:
Glomerular filtration of water and solutes from the blood.
Tubular reabsorption of water and conserved molecules back into the blood.
Tubular secretion of ions and other waste products from surrounding capillaries into the distal tubule.
Nephrons filter 125 ml of body fluid per minute; filtering the entire body fluid component 16 times each day. In a 24 hour period nephrons produce 180 liters of filtrate, of which 178.5 liters are reabsorbed. The remaining 1.5 liters forms urine.
Urine Production
Filtration in the glomerulus and nephron capsule.
Reabsorption in the proximal tubule.
Tubular secretion in the Loop of Henle.
Components of The Nephron
Glomerulus: mechanically filters blood
Bowman's Capsule: mechanically filters blood
Proximal Convoluted Tubule: Reabsorbs 75% of the water, salts, glucose, and amino acids
Loop of Henle: Countercurrent exchange, which maintains the concentration gradient
Distal Convoluted Tubule: Tubular secretion of H ions, potassium, and certain drugs.
Kidney Stones
In some cases, excess wastes crystallize as kidney stones. They grow and can become a painful irritant that may require surgery or ultrasound treatments. Some stones are small enough to be forced into the urethra, others are the size of huge, massive boulders (or so I am told).
Kidney Function
Kidneys perform a number of homeostatic functions:
Maintain volume of extracellular fluid
Maintain ionic balance in extracellular fluid
Maintain pH and osmotic concentration of the extracellular fluid.
Excrete toxic metabolic by-products such as urea, ammonia, and uric acid.
Hormone Control of Water and Salt | Back to Top
Water reabsorption is controlled by the antidiuretic hormone (ADH) in negative feedback. ADH is released from the pituitary gland in the brain. Dropping levels of fluid in the blood signal the hypothalamus to cause the pituitary to release ADH into the blood. ADH acts to increase water absorption in the kidneys. This puts more water back in the blood, increasing the concentration of the urine. When too much fluid is present in the blood, sensors in the heart signal the hypothalamus to cause a reduction of the amounts of ADH in the blood. This increases the amount of water absorbed by the kidneys, producing large quantities of a more dilute urine.
Aldosterone, a hormone secreted by the kidneys, regulates the transfer of sodium from the nephron to the blood. When sodium levels in the blood fall, aldosterone is released into the blood, causing more sodium to pass from the nephron to the blood. This causes water to flow into the blood by osmosis. Renin is released into the blood to control aldosterone.
Disruption of Kidney Function
Infection, environmental toxins such as mercury, and genetic disease can have devastating results by causing disruption of kidney function. Many kidney problems can be treated by dialysis, where a machine acts as a kidney. Kidney transplants are an alternative to dialysis.
Cells produce water and carbon dioxide as by-products of metabolic breakdown of sugars, fats, and proteins. Chemical groups such as nitrogen, sulfur, and phosphorous must be stripped, from the large molecules to which they were formerly attached, as part of preparing them for energy conversion. The continuous production of metabolic wastes establishes a steep concentration gradient across the plasma membrane, causing wastes to diffuse out of cells and into the extracellular fluid.
Single-celled organisms have most of their wastes diffuse out into the outside environment. Multicellular organisms, and animals in particular, must have a specialized organ system to concentrate and remove wastes from the interstitial fluid into the blood capillaries and eventually deposit that material at a collection point for removal entirely from the body
Excretory systems regulate the chemical composition of body fluids by removing metabolic wastes and retaining the proper amounts of water, salts, and nutrients. Components of this system in vertebrates include the kidneys, liver, lungs, and skin.
Not all animals use the same routes or excrete their wastes the same way humans do. Excretion applies to metabolic waste products that cross a plasma membrane. Elimination is the removal of feces.
Water and Salt Balance | Back to Top
The excretory system is responsible for regulating water balance in various body fluids. Osmoregulation refers to the state aquatic animals are in: they are surrounded by freshwater and must constantly deal with the influx of water. Animals, such as crabs, have an internal salt concentration very similar to that of the surrounding ocean. Such animals are known as osmoconformers, as there is little water transport between the inside of the animal and the isotonic outside environment.
Marine vertebrates, however, have internal concentrations of salt that are about one-third of the surrounding seawater. They are said to be osmoregulators. Osmoregulators face two problems: prevention of water loss from the body and prevention of salts diffusing into the body. Fish deal with this by passing water out of their tissues through their gills by osmosis and salt through their gills by active transport. Cartilaginous fish have a greater salt concentration than seawater, causing water to move into the shark by osmosis; this water is used for excretion. Freshwater fish must prevent water gain and salt loss. They do not drink water, and have their skin covered by a thin mucus. Water enters and leaves through the gills and the fish excretory system produces large amounts of dilute urine.
Terrestrial animals use a variety of methods to reduce water loss: living in moist environments, developing impermeable body coverings, production of more concentrated urine. Water loss can be considerable: a person in a 100 degree F temperature loses 1 liter of water per hour.
Excretory System Functions | Back to Top
Collect water and filter body fluids.
Remove and concentrate waste products from body fluids and return other substances to body fluids as necessary for homeostasis.
Eliminate excretory products from the body.
Invertebrate Excretory Organs | Back to Top
Many invertebrates such as flatworms use a nephridium as their excretory organ. At the end of each blind tubule of the nephridium is a ciliated flame cell. As fluid passes down the tubule, solutes are reabsorbed and returned to the body fluids
CARDIO VASCULAR SYSTEM
CARDIO VASCULAR SYSTEM
1) What are the two parts of the cardiovascular system?
Blood
Blood vessels and the heart
(2) What are the functions of the cardiovascular system?
The heart pumps blood all through the body.
The blood helps fight infections, regulates temperature, and regulated ph levels.
(3) What are the types of blood vessels?
Arteries, capillaries, and veins.
(4) What is the structure and function of these vessels?
Arteries: Consists of three levels. 1) Endothelium: thin cells that make up the inner level 2) Middle layer is smooth muscle 3) The outer layer is connective tissue. These walls allow the artery to be protect under pressure and allows them to expand. Arteries carry blood from the heart.
Capillaries: Arterioles branch out and become capillaries. Capillaries are made of endothelium.
Veins: Veins have the same layers as arteries but has less of the middle layer. Veins are thinner than arteries, because of this they can expand further. Veins carry blood to the heart.
(5) Why is the heart a double pump?
The heart is a double pump because it is pumping blood to the lungs and blood to the body at the same time but they never intersect.
(6) What causes the "lub" and the "dup" of the heart sounds?
Lub: "Cusps of Av valve" slam shut due to pressure
Dup: When the ventricles relax and the blood begins to glow again.
(7) What keeps the heart beat regular?
The SA node sends a signal ever .85 seconds which causes the atria to contract. The signal is then sent to the AV.
(8) What does the pulse rate of a person indicate?
The pulse rate tells how many beats the heart has beat in a minute.
(9) What accounts for blood flow in the arteries?
The blood flow in the arteries is called blood pressure .
(10) What accounts for blood flow in the veins?
Skeletal pump: caused by skeletal muscle contraction
Respiratory Pump: caused by breathing
valves in the veins
The human body consists of many organs that are useful to carry out the functions of the body properly. All organs in the body are very much essential for normal functioning of the human body. In the similar manner, cardiovascular system is the most essential part of the body. It comprises of three main parts: blood, the heart, and the blood vessels, arteries and capillary veins.
The main function of cardiovascular system is to transport oxygen to all other organs of the body. Thus, this process provides sufficient amount of nutrition to several parts of the body. It is the most interesting and essential component of the body. Many researchers and scientist have toiled their life to get all the detailed information about this system. Every part of the system has different facts and functions. Thus, we may discuss here some interesting facts about blood, heart and blood vessels.
Blood:
Blood is the nutrition of the body that provides us energy for survival. Blood is actually a carrier of nutrition and oxygen to all other organs and cells of the body. Some interesting facts will help you to understand the proper functioning of blood.
Blood is made up of blood cells which are in the form of liquid, known as blood plasma. Seven % of the blood comprises in the total weight of the body. An adult human body contains an average of five liters of blood. There are two types of blood in the body: Red blood cells (RBC) and white blood cells (WBC). Blood even comprises of leukocytes and platelets. Hemoglobin is the main component of RBC, which is protein with iron that is very much essential for body to transport oxygen. Blood is made up of connective tissues and is generated within bones.
Heart:
The heart is the most important component of the body. It supplies blood and oxygen to all other parts of the body. The heart of male weighs approximately 300-350 grams whereas, female heart weight almost 250-300 grams. Its size is equivalent to the size of your hand fist. The heart is wrapped by double layer sac- Pericardium. Our heart is made up of three main parts: Innermost layer (Endocardium), Middle layer (Myocardium) and the Uppermost layer( Visceral layer) Heart comprises of four chambers: two arteries and two ventricles.
Blood vessels:
Blood vessels transport blood to the heart and other organs of the body.
The blood vessels in divided into three types: veins, capillaries and arteries. Each blood vessel carries out an important function of the body. The veins transport blood cells to the heart while, arteries pull away the blood from the heart. The Capillaries exchange chemicals with water. Aorta is the largest artery in the blood vessels that transports the blood from the heart. It is divided into: carotid artery, celiac trunk, renal artery, iliac artery, subclavian artery, and mesenteric arteries.
The heart is the pump responsible for maintaining adequate circulation of oxygenated blood around the vascular network of the body. It is a four-chamber pump, with the right side receiving deoxygenated blood from the body at low presure and pumping it to the lungs (the pulmonary circulation) and the left side receiving oxygenated blood from the lungs and pumping it at high pressure around the body (the systemic circulation).
The myocardium (cardiac muscle) is a specialised form of muscle, consisting of individual cells joined by electrical connections. The contraction of each cell is produced by a rise in intracellular calcium concentration leading to spontaneous depolarisation, and as each cell is electrically connected to its neighbour, contraction of one cell leads to a wave of depolarisation and contraction across the myocardium.
This depolarisation and contraction of the heart is controlled by a specialised group of cells localised in the sino-atrial node in the right atrium- the pacemaker cells. These cells generate a rhythmical depolarisation, which then spreads out over the atria to the atrio-ventricular node.
The atria then contract, pushing blood into the ventricles.
The electrical conduction passes via the Atrio-ventricular node to the bundle of His, which divides into right and left branches and then spreads out from the base of the ventricles across the myocardium.
This leads to a 'bottom-up' contraction of the ventricles, forcing blood up and out into the pulmonary artery (right) and aorta (left).
The atria then re-fill as the myocardium relaxes.
The 'squeeze' is called systole and normally lasts for about 250ms. The relaxation period, when the atria and ventricles re-fill, is called diastole; the time given for diastole depends on the heart rate
RESPIRATORY SYSTEM
Respiratory System
Anatomy of the Respiratory System
What is respiration?
Respiration is the act of breathing:
inhaling (inspiration) - taking in oxygen
exhaling (expiration) - giving off carbon dioxide
What makes up the respiratory system?
The respiratory system is made up of the organs involved in breathing and consists of the:
nose
pharynx
larynx
trachea
bronchi
lungs
The upper respiratory tract includes the:
nose
nasal cavity
ethmoidal air cells
frontal sinuses
maxillary sinus
larynx
trachea
The lower respiratory tract includes the:
lungs
bronchi
alveoli
What do lungs do?
The lungs take in oxygen, which all cells throughout the body need to live and carry out their normal functions. The lungs also get rid of carbon dioxide, a waste product of the body's cells.
The lungs are a pair of cone-shaped organs made up of spongy, pinkish-gray tissue. They take up most of the space in the chest, or the thorax (the part of the body between the base of the neck and diaphragm).
The lungs are inside in a membrane called the pleura.
The lungs are separated from each other by the mediastinum, an area that contains the following:
heart and its large vessels
trachea (windpipe)
esophagus
thymus
lymph nodes
The right lung has three sections, called lobes. The left lung has two lobes. When you breathe, the air:
enters the body through the nose or the mouth
travels down the throat through the larynx (voice box) and trachea (windpipe)
goes into the lungs through tubes called main-stem bronchi
one main-stem bronchus leads to the right lung and one to the left lung
in the lungs, the main-stem bronchi divide into smaller bronchi
and then into even smaller tubes called bronchioles
bronchioles end in tiny air sacs called alveoli
Every minute we breathe, we take in 13 pints of air! That is we breathe about 6.15 liters of air every minute.
We breathe about 9 to 20 times every minute. Through every breath, we breathe in about half a liter of air.
We inhale and exhale air about 22,000 times per day and in the process, transport about 300 cubic feet of air (which is about 8.5 cubic meters of air)!
Human breathing mechanism is called tidal breathing, as air comes out the same way it goes in.
We exhale about half a liter of water vapor in a whole day.
Breathing is initiated by the diaphragm, which is a stretchable muscle under the lungs. When it contracts, the volume of the chest cavity rises and the air pressure drops. That is what enables the high pressure air outside, to enter the lungs and makes them expand like balloons.
When the diaphragm expands, lungs are emptied of air and we exhale it outside.
When air passes through the nose and into the nasal passage called the windpipe, it gets filtered, moistened and heated.
Breathing Mechanism
Humans breathe by flattening and contracting the diagram for inhalation and relaxing the diaphragm for exhalation. Intercostal muscles assist breathing.
In humans the chest cavity, or thorax, is separated from the abdominal cavity by a dome shaped muscle called the diaphragm.
Two lungs are enclosed within the thorax, which is supported by the ribs, and they are connected to the mouth and nose by the trachea. In an adult the trachea is about 11 cm long and 2.5 cm in diameter. It is supported by several horseshoe-shaped sections of cartilage that prevent the trachea collapsing and closing the airway.
Inhalation
On inhalation the diaphragm contracts and becomes flatter as it is lowered. In addition, the lower ribs swing upwards and outwards as the external intercostal muscles contract. These movements increase the volume of the thorax and the pressure within it falls to below atmospheric pressure. Consequently, air rushes into the lungs to fill this partial vacuum.
Exhalation
Relaxation of the external intercostals and the diaphragm allow a set of opposing muscles, the internal intercostal muscles, to return the thorax to its previous size. As the thorax diminishes in size air is expelled from the lungs. All English speech sounds are composed using exhaled air from the lungs, i.e. using a pulmonic air stream.
DIGESTIVE SYSTEM
The human digestive system is a complex series of organs and glands that processes food. In order to use the food we eat, our body has to break the food down into smaller molecules that it can process; it also has to excrete waste.
Most of the digestive organs (like the stomach and intestines) are tube-like and contain the food as it makes its way through the body. The digestive system is essentially a long, twisting tube that runs from the mouth to the anus, plus a few other organs (like the liver and pancreas) that produce or store digestive chemicals.
The Digestive Process:
The start of the process - the mouth: The digestive process begins in the mouth. Food is partly broken down by the process of chewing and by the chemical action of salivary enzymes (these enzymes are produced by the salivary glands and break down starches into smaller molecules).
On the way to the stomach:
the esophagus - After being chewed and swallowed, the food enters the esophagus. The esophagus is a long tube that runs from the mouth to the stomach. It uses rhythmic, wave-like muscle movements (called peristalsis) to force food from the throat into the stomach. This muscle movement gives us the ability to eat or drink even when we're upside-down.
In the stomach -
The stomach is a large, sack-like organ that churns the food and bathes it in a very strong acid (gastric acid). Food in the stomach that is partly digested and mixed with stomach acids is called chyme.
In the small intestine -
After being in the stomach, food enters the duodenum, the first part of the small intestine. It then enters the jejunum and then the ileum (the final part of the small intestine). In the small intestine, bile (produced in the liver and stored in the gall bladder), pancreatic enzymes, and other digestive enzymes produced by the inner wall of the small intestine help in the breakdown of food.
In the large intestine -
After passing through the small intestine, food passes into the large intestine. In the large intestine, some of the water and electrolytes (chemicals like sodium) are removed from the food. Many microbes (bacteria like Bacteroides, Lactobacillus acidophilus, Escherichia coli, and Klebsiella) in the large intestine help in the digestion process. The first part of the large intestine is called the cecum (the appendix is connected to the cecum). Food then travels upward in the ascending colon. The food travels across the abdomen in the transverse colon, goes back down the other side of the body in the descending colon, and then through the sigmoid colon.
The end of the process - Solid waste is then stored in the rectum until it is excreted via the anus.
Digestive System Glossary:
abdomen
- the part of the body that contains the digestive organs. In human beings, this is between the diaphragm and the pelvis
alimentary canal - the passage through which food passes, including the mouth, esophagus, stomach, intestines, and anus.
anus - the opening at the end of the digestive system from which feces (waste) exits the body.
appendix - a small sac located on the cecum.
ascending colon - the part of the large intestine that run upwards; it is located after the cecum.
bile - a digestive chemical that is produced in the liver, stored in the gall
bladder, and secreted into the small intestine.
cecum - the first part of the large intestine; the appendix is connected to the cecum.
chyme - food in the stomach that is partly digested and mixed with stomach acids.
Chyme goes on to the small intestine for further digestion.
descending colon - the part of the large intestine that run downwards after the transverse colon and before the sigmoid colon.
digestive system - (also called the gastrointestinal tract or GI tract) the system of the body that processes food and gets rid of waste.
duodenum - the first part of the small intestine; it is C-shaped and runs from the stomach to the jejunum.
epiglottis - the flap at the back of the tongue that keeps chewed food from going down the windpipe to the lungs. When you swallow, the epiglottis automatically closes. When you breathe, the epiglottis opens so that air can go in and out of the windpipe.
esophagus - the long tube between the mouth and the stomach. It uses rhythmic muscle movements (called peristalsis) to force food from the throat into the stomach.
gall bladder - a small, sac-like organ located by the duodenum. It stores and releases bile (a digestive chemical which is produced in the liver) into the small intestine.
gastrointestinal tract - (also called the GI tract or digestive system) the system of the body that processes food and gets rid of waste.
ileum - the last part of the small intestine before the large intestine begins.
intestines - the part of the alimentary canal located between the stomach and the anus.
jejunum - the long, coiled mid-section of the small intestine; it is between the duodenum and the ileum.
liver - a large organ located above and in front of the stomach. It filters toxins from the blood, and makes bile (which breaks down fats) and some blood proteins.
mouth - the first part of the digestive system, where food enters the body. Chewing and salivary enzymes in the mouth are the beginning of the digestive process (breaking down the food).
pancreas - an enzyme-producing gland located below the stomach and above the intestines. Enzymes from the pancreas help in the digestion of carbohydrates, fats and proteins in the small intestine.
peristalsis - rhythmic muscle movements that force food in the esophagus from the throat into the stomach. Peristalsis is involuntary - you cannot control it. It is also what allows you to eat and drink while upside-down.
rectum - the lower part of the large intestine, where feces are stored before they are excreted.
salivary glands - glands located in the mouth that produce saliva. Saliva contains enzymes that break down carbohydrates (starch) into smaller molecules.
sigmoid colon - the part of the large intestine between the descending colon and the rectum.
stomach - a sack-like, muscular organ that is attached to the esophagus. Both chemical and mechanical digestion takes place in the stomach. When food enters the stomach, it is churned in a bath of acids and enzymes.
transverse colon - the part of the large intestine that runs horizontally across the abdomen.
SKELETAL SYSTEM
The 3 Types of Muscle:
Skeletal Muscle-attached to and moves bones. You can control their contracts.
Smooth Muscle-squeezes, exerts pressure inside the tube or organ which it surrounds. Found inside the walls of internal organs, and blood vessels.
Cardiac Muscle-helps the heart muscle contract. Generates and conducts electrical impulses which give rhythmic contractions.
Tendons:
Thick bands of connective tissue
Attaches bones to muscles
Ligaments:
Tough bands of connective tissue
Attaches one bone to another
Joints:
Where two or more bones meet
Immovable joints are held together by the inter growth of a bone or by fibrous cartilaye
Can be fixed or facilitate movement of bones in relation to one another
Possible muscles/Organs injured in Robin:
Smooth Muscle (Caused the bleeding?)
Skeletal Muscle (Causing the shaking?)
Kidneys (Cause of the blood in the pee)
Intestines (Cause of the blood from the anus)
Muscular System:
Groups of fibers, or cells, bound together
Muscle tissues is made up of units called myofibrils
Contractions and relaxation of muscles create movements
Makes body stronger
Skeletal System:
Contains about 206 bones
Axial Skeleton-contains the skull and bones that support the body
Appendicular Skeleton-includes the bones of the arms and legs, and structures associated with them
Protects internal organs
Provides framework for the tissues of your body
Produces red blood cells
Stores minerals
Bones may be a sponge like material
Muscular system with other systems:
Works with the skeletal system to provide skeletal movement
Works with the digestive system to control entrances and exits of digestive tract
Works with the endocrine system to produce heat
Works with the nervous system to sense things
Works with the respiratory system to allow the diaphragm to expand
Works with the cardiovascular system to provide circulation
Skeletal system with other systems:
Provides protection for organs (cranium for brain, ribs for lung etc.)
Provides attachments for muscles
Bone marrow makes blood components
Bone releases and absorbs minerals (e.g. calcium).
BONE
A fully developed bone is made up of mineral salts, water and tissue. There are two types of bone - compact and cancellate. A compact bone is smooth and solid, while a cancellate bone is a much lighter structure. The structure of the cancellate bone is similar to a honeycomb. All bones are a combination of cancellate and compact bone.
Inside each bone is a jelly like substance. This is called bone marrow and is at the center of the bone. This marrow produces blood cells for the body. Blood vessels run through the center of the bone so that the bone receives food, oxygen and minerals.
Bone is one of the strongest materials. Bones are much lighter than steel or concrete, but weight for weight, they are much stronger.
What is the Skeletal System?
Your Skeletal system is all of the bones in the body and the tissues such as tendons, ligaments and cartilage that connect them.
Your teeth are also considered part of your skeletal system but they are not counted as bones. Your teeth are made of enamel and dentin. Enamel is the strongest substance in your body.
How does the Skeletal System help us?
Support
The main job of the skeleton is to provide support for our body. Without your skeleton your body would collapse into a heap. Your skeleton is strong but light. Without bones you'd be just a puddle of skin and guts on the floor.
Protection
Your skeleton also helps protect your internal organs and fragile body tissues. The brain, eyes, heart, lungs and spinal cord are all protected by your skeleton. Your cranium (skull) protects your brain and eyes, the ribs protect your heart and lungs and your vertebrae (spine, backbones) protect your spinal cord.
Movement
Bones provide the structure for muscles to attach so that our bodies are able to move. Tendons are tough inelastic bands that hold attach muscle to bone.
Contents
Who has more bones a baby or an adult?
Babies have more than adults! At birth, you have about 300 bones. As you grow older, small bones join together to make big ones. Adults end up with about 206 bones.
Are bones alive?
Absolutely. Old bones are dead, dry and brittle. But in the body, bones are very much alive. They have their own nerves and blood vessels, and they do various jobs, such as storing body minerals like calcium. Bones are made of a mix of hard stuff that gives them strength and tons of living cells which help them grow and repair themselves.
What is a bone made of?
A typical bone has an outer layer of hard or compact bone, which is very strong, dense and tough. Inside this is a layer of spongy bone, which is like honeycomb, lighter and slightly flexible. In the middle of some bones is jelly-like bone marrow, where new cells are constantly being produced for the blood. Calcium is an important mineral that bone cells need to stay strong so keep drinking that low-fat milk!
Contents
How do bones break and heal?
Bones are tough and usually don't break even when we have some pretty bad falls. I'm sure you have broken a big stick at one time. When you first try to break the stick it bends a bit but with enough force the stick finally snaps. It is the same with your bones. Bones will bend a little, but if you fall the wrong way from some playground equipment or maybe your bike or skateboard you can break a bone. Doctors call a broken bone a fracture. There are many different types of fractures.
Luckily, bones are made of living cells. When a bone is broken your bone will produce lots of new cells to rebuild the bone. These cells cover both ends of the broken part of the bone and close up the break.
How do I keep my bones healthy?
Bones need regular exercise to stay as strong as possible. Walking, jogging, running and other physical activities are important in keeping your bones strong and healthy. Riding your bike, basketball, soccer, gymnastics, baseball, dancing, skateboarding and other activities are all good for your bones. Make sure you wear or use the proper equipment like a helmet, kneepads, shin guards, mats, knee pads, etc... to keep those bones safe.
Strengthen your skeleton by drinking milk and eating other dairy products (like low-fat cheese, frozen yogurt, and ice cream). They all contain calcium, which helps bones harden and become strong.
ENDOCRINE SYSTEM
Endocrine System
The nervous system sends electrical messages to control and coordinate the body. The endocrine system has a similar job, but uses chemicals to “communicate”. These chemicals are known as hormones. A hormone is a specific messenger molecule synthesized and secreted by a group of specialized cells called an endocrine gland. These glands are ductless, which means that their secretions (hormones) are released directly into the bloodstream and travel to elsewhere in the body to target organs, upon which they act. Note that this is in contrast to our digestive glands, which have ducts for releasing the digestive enzymes.
Pheromones are also communication chemicals, but are used to send signals to other members of the same species. Queen bees, ants, and naked mole rats exert control of their respective colonies via pheromones. One common use for pheromones is as attractants in mating. Pheromones are widely studied in insects and are the basis for some kinds of Japanese beetle and gypsy moth traps. While pheromones have not been so widely studied in humans, some interesting studies have been done in recent years on pheromonal control of menstrual cycles in women. It has been found that pheromones in male sweat and/or sweat from another “dominant” female will both influence/regulate the cycles of women when smeared on their upper lip, just below the nose. Also, there is evidence that continued reception of a given man’s pheromone(s) by a woman in the weeks just after ovulation/fertilization can significantly increase the chances of successful implantation of the new baby in her uterus. Pheromones are also used for things like territorial markers (urine) and alarm signals.
Each hormone’s shape is specific and can be recognized by the corresponding target cells. The binding sites on the target cells are called hormone receptors. Many hormones come in antagonistic pairs that have opposite effects on the target organs. For example, insulin and glucagon have opposite effects on the liver’s control of blood sugar level. Insulin lowers the blood sugar level by instructing the liver to take glucose out of circulation and store it, while glucagon instructs the liver to release some of its stored supply to raise the blood sugar level. Much hormonal regulation depends on feedback loops to maintain balance and homeostasis.
There are three general classes (groups) of hormones. These are classified by chemical structure, not function.
steroid hormones including prostaglandins which function especially in a variety of female functions (aspirin inhibits synthesis of prostaglandins, some of which cause “cramps”) and the sex hormones all of which are lipids made from cholesterol,
amino acid derivatives (like epinephrine) which are derived from amino acids, especially tyrosine, and
peptide hormones (like insulin) which is the most numerous/diverse group of hormones.
The major human endocrine glands include:
the hypothalamus and pituitary gland
The pituitary gland is called the “master gland” but it is under the control of the hypothalamus. Together, they control many other endocrine functions. They secrete a number of hormones, especially several which are important to the female menstural cycle, pregnancy, birth, and lactation (milk production). These include follicle-stimulating hormone (FSH), which stimulates development and maturation of a follicle in one of a woman’s ovaries, and leutinizing hormone (LH), which causes the bursting of that follicle (= ovulation) and the formation of a corpus luteum from the remains of the follicle.
There are a number of other hypothalamus and pituitary hormones which affect various target organs.
One non-sex hormone secreted by the posterior pituitary is antidiuretic hormone or ADH. This hormone helps prevent excess water excretion by the kidneys. Ethanol inhibits the release of ADH and can, thus, cause excessive water loss. That’s also part of the reason why a group of college students who go out for pizza and a pitcher of beer need to make frequent trips to the restrooms. Diuretics are chemicals which interfere with the production of or action of ADH so the kidneys secrete more water. Thus diuretics are often prescribed for people with high blood pressure, in an attempt to decrease blood volume.
Another group of non-sex hormones that many people have heard of is the endorphins, which belong to the category of chemicals known as opiates and serve to deaden our pain receptors. Endorphins, which are chemically related to morphine, are produced in response to pain. The natural response to rub an injured area, such as a pinched finger, helps to release endorphins in that area. People who exercise a lot and push their bodies “until it hurts” thereby stimulate the production of endorphins. It is thought that some people who constantly over-exercise and push themselves too much may actually be addicted to their own endorphins which that severe exercise regime releases.
the thyroid gland
Thyroid hormones regulate metabolism, therefore body temperature and weight. The thyroid hormones contain iodine, which the thyroid needs in order to manufacture these hormones. If a person lacks iodine in his/her diet, the thyroid cannot make the hormones, causing a deficiency. In response to the body’s feedback loops calling for more thyroid hormones, the thyroid gland then enlarges to attempt to compensate (The body’s plan here is if it’s bigger it can make more, but that doesn’t help if there isn’t enough iodine.). This disorder is called goiter. Dietary sources of iodine include any “ocean foods” because ocean-dwelling organisms tend to accumulate iodine from the seawater, and would include foods like ocean fish (tuna) and seaweeds like kelp. Because of this, people who live near the ocean do not have as much of a problem with goiter as people who live inland and don’t have access to these foods. To help alleviate this problem in our country, our government began a program encouraging salt refiners to add iodine to salt, and encouraging people to choose to consume this iodized salt.
the pancreas
This organ has two functions. It serves as a ducted gland, secreting digestive enzymes into the small intestine. The pancreas also serves as a ductless gland in that the islets of Langerhans secrete insulin and glucagon to regulate the blood sugar level. The -islet cells secrete glucagon, which tells the liver to take carbohydrate out of storage to raise a low blood sugar level. The -islet cells secrete insulin to tell the liver to take excess glucose out of circulation to lower a blood sugar level that’s too high. If a person’s body does not make enough insulin (and/or there is a reduced response of the target cells in the liver), the blood sugar rises, perhaps out of control, and we say that the person has diabetes mellitus.
the adrenal glands
These sit on top of the kidneys. They consist of two parts, the outer cortex and the inner medulla. The medulla secretes epinephrine (= adrenaline) and other similar hormones in response to stressors such as fright, anger, caffeine, or low blood sugar. The cortex secretes corticosteroids such as cortisone. Corticosteroids are well-known as being anti-inflammatory, thus are prescribed for a number of conditions. However, these are powerful regulators that should be used with caution. Medicinal doses are typically higher than what your body would produce naturally, thus the person’s normal feedback loops suppress natural secretion, and it is necessary to gradually taper off the dosage to trigger the adrenal glands to begin producing on their own again. Because the corticosteroids suppress the immune system, their use can lead to increased susceptibility to infections, yet physicians typically prescribe them for people whose immune systems are hard at work trying to fight off some pathogen. For example, back when I was in grad school, I was diagnosed with mono, and the campus doctor prescribed penicillin and cortisone. Since mono is a virus and penicillin only is effective against some bacteria, about all it did was kill off the friendly bacteria in my body, therefore causing me to develop a bad case of thrush. At the same time, the cortisone was supressing my immune system so my body could not as efficiently fight off the mono and the thrush. People with high blood pressure should be leery of taking prescription corticosteroids: they are known to raise blood pressure, thus can cause things like strokes. My mother-in-law had high blood pressure and was being treated with diuretics. Her physician also had her on large doses of cortisone for her arthritis. While he was on vacation, she started having significant back pain and was referred to an orthopedic surgeon. This man decided the back pain was just due to arthritis, and without carefully checking on what dosage she was already taking, prescribed more cortisone. Simultaneously, because of difficulty walking due to her arthritis, she decided to decrease the amount of diuretics she was taking so she didn’t have to make as many “long” trips to the other end of the house. The combination of lowered dose of diuretics and high dose of cortisone raised her blood pressure to the point where a blood vessel in her brain burst, causing a stroke. When the EMTs took her blood pressure, as I recall the systolic was way over 200 mm Hg.
the gonads or sex organs
In addition to producing gametes, the female ovaries and male testes (singular = testis) also secrete hormones. Therefore, these hormones are called sex hormones. The secretion of sex hormones by the gonads is controlled by pituitary gland hormones such as FSH and LH. While both sexes make some of each of the hormones, typically male testes secrete primarily androgens including testosterone. Female ovaries make estrogen and progesterone in varying amounts depending on where in her cycle a woman is. In a pregnant woman, the baby’s placenta also secretes hormones to maintain the pregnancy.
the pineal gland
This gland is located near the center of the brain in humans, and is stimulated by nerves from the eyes. In some other animals, the pineal gland is closer to the skin and directly stimulated by light (some lizards even have a third eye). The pineal gland secreted melatonin at night when it’s dark, thus secretes more in winter when the nights are longer. Melatonin promotes sleep (makes you feel sleepy). It also affects reproductive functions by depressing the activity of the gonads. Additionally, it affects thyroid and adrenal cortex functions. In some animals, melatonin affects skin pigmentation. Because melatonin production is affected by the amount of light to which a person is exposed, this is tied to circadian rhythm (having an activity cycle of about 24 hours), annual cycles, and biological clock functions. SAD or seasonal affective disorder (syndrome) is a disorder in which too much melatonin is produced, especially during the long nights of winter, causing profound depression, oversleeping, weight gain, tiredness, and sadness. Treatment consists of exposure to bright lights for several hours each day to inhibit melatonin production. It has also been found that melatonin levels drop 75% suddenly just before puberty, suggesting the involvement of melatonin in the regulation of the onset of puberty. Studies have been done on blind girls (with a form of blindness in which no impulses can travel down the optic nerve and reach the brain and pineal gland), which showed that these girls tended to have higher levels of melatonin for a longer time, resulting in a delay in the onset of puberty. While some older people, who don’t make very much melatonin, thus don’t sleep well, might benefit from a melatonin supplement, I’m skeptical of the recent melatonin craze in this country. When so many people apparently are suffering from SAD, I question the wisdom of purposly ingesting more melatonin, especially since the pineal gland is one of the least-studied, least-understood of the endocrine glands.
Local regulators are hormones with target cells nearby or adjacent to the endocrine gland in question. For example, neurotransmitters are secreted in the synapses of our nervous system and their target cells are in the same synapses.
ENDOCRINE SYSTEM - YOGIC VIEW
First Chakra
The first chakra is located at the base of the spine, it is said that the Kundalini serpent (Shakti) lies coiled there waiting to be released and Merged with Shiva in the crown center. The color of this base energy center is red and its orientation is that of survival. It is the animal instinct which lies within all of us that urges us to survive.
People that do not have enough flow of energy through this chakra do not feel as though they are secure in the world, there daily life is a battle just to stay above water and they are typically on edge.
This center has to due with elimination, when energy flows freely through this center one is able to release, and let go, of that which could slow them down.
Benefits of a Balanced First Chakra
Sense of groundedness
Security
A stable base from which to move forward
The 1st chakra is ever so important because it allows us to feel connected to the earth. It is the first chakra that tells us to walk bare foot on the beach, it is the first charkra that tells us nature is a beautiful thing. And it is the 1st chakra that helps those more spiritually inclined to keep their feet on the ground as their head dances in the clouds
Second Chakra- Svadhisthana
The second chakra is located just above the base of the spine around ones sex organs. This energy center has to do with creativity, specifically around the creation of life. Orange is the color of the 2nd Chakra. There is a large imbalance in our society in the second center due to mass media glorifying sexuality, without the presence of love
When this chakra is blocked it manifests itself with a deep sense of insecurity with ones own sexuality. A person with an over active 2nd chakra will tend to focus on sex too much.
The second chakra builds upon the survival instincts of the 1st chakra, by Desire. The desire to pass along our genetic blue print and produce off spring.
Benefits of a Balanced 2nd Chakra
Proper flow of energy through reproductive organs
Healthy sex life
Ability to properly focus creative energy
Once one has properly balanced the sacral center they are able to transmute the creative energies of the second chakra into the higher centers and express the divine creativity from within.
Third Chakra- Manipura (Personal Power)
The 3rd Chakra is located in the belly. It is the seat of ones personal power. It directly affects ones ability to project their will into manifestation. This center is one that is constantly challenged in humanity . The majority of people are constantly having their power chakras challenged weather it be at work, in our relationships, or simply within ourselves. Power struggles are contsant in our daily grind. An under active third chakra can lead to a true feeling of powerlessness. An over active 3rd center can be just as detrimental as an under active one and may result in the over powering of others, typically for selfish desire.
The root of this problem stems from not transfering the energy of the 3rd center up through the heart center. The power that stems from the third chakra, balanced in love will lead humanity to a grand state of peace and well being.
The 3rd center is commonly associated with the “core” balancing activities that many aerobics focus on. The focus on this core, or power center, allows people to feel in control of their own destiny. As it is located in the belly it is also tied into the digestive system. When we are stressed we tend to get indigestion, which is merely a symptom of an unbalanced 3rd chakra.
This energy center is typically associated with the color Yellow, or Gold.
Benefits of a Balanced 3rd Chakra
Properly porportioned sense of self
Ability to influence/change ones surrounding environment
Strong digestive system
Core stability
As the power center this chakra helps to regulate the flow of energy to the other centers. By clearing this chakra of imbalances we can operate powerfully in our environment. This leads to an improved sense of self, and self esteem, which in turns increases our ability to help others.
Fourth Chakra- Anahata (Heart Center)
The 4th chakra lies between the shoulder blades slightly higher than the physical heart.
The focus of the heart center is non other than love and balance. It is from within the heart center that the Lord of Love shines forth in all of us. The heart center plays an important role in the balancing of the chakra system. In order to achieve a proper balance and flow of energy through the chakras, that energy must be integrated across the heart center. The blending of the higher and lower centers, (though each equally important) must be acheived across the heart center.
One means of achieving balance across the charka system is to take an inventory of what centers are out of balance. See to it that as you work on balancing each of those centers that you even out the balancing across the heart center. If weeek 1 you work on your 1st Chakra, and your 7th Chakra is out of balance as well, then try working on your 7th Chakra the next week. As you work with these energy centers you will find that the blockages move as your life moves. I speak only from my own personal experience in working with these centers over the past couple of years, (in this life time.)
When a person is blocked in the Heart Center it may manifest as a lack of abilty to give freely, or a lack of resources. The Heart Center tends to be an area that humanity requires the most healing in, who hasn’t been hurt by a loving relationship in the past. An ironic twist is that the Heart Center is also the primary center from which healing flows.
The color of the fourth chakra, is green. Green the color of abundance and good fortune. Pink is another potential color for this center, which represents a balancing of the White Light from above with the Red of the 1st Chakra.
Benefits of a Balanced Fourth Chakra
Love
Ability to give freely to others
Abundance
Healing for ones self and others
Integration of the higher and lower energy centers
Meditation from the Heart Center is an excellent means of polling our higher selves for what is right. If you hear your heart speak it to you then follow it. I have been working on allowing my heart to guide me for sometime, which is challenging considering my head likes to think it controls things The path may not be the one most easily taken, but listening to and operating from the heart center will help you to achieve your purpose.
The Heart Center represents Love. What a fantastic quailty to work on balancing
Thyroid Disease
It has come to my attention that a good number of individuals suffer from Thyroid Disease, of some sort or another, and it appears as though women are more likely to have difficulties than men. Weather it is an underactive thyroid, or an overactive thyroid the imbalance in the endocrine system is simply devistating to ones health. This ailment faces my mother and one of my co-workers as well, so it really hits home for me.
As I work through my studies of Kundalini Yoga I am researching the human endocrine system, and outlining some thoughts for chakra-neuroendocrinology, (a science that the yogis have understood for some time, but requires additional Western study.)
My study now takes me to the Thyroid. I seek to gain an understanding of its function and make the case for Kundalini Yoga as a Preventative Maintenance program to keep thyroid disease and disorders away. (Yoga is a maintenance program for the body, mental, emotional and spiritual, as well, but let’s stay focused on this aspect for the time.)
In my previous post on chakra-neuroendocrinology I referenced a resource book that is helping me understand the system. My high level overviews of the tyroid, based on the book, and other insights are as follows:
The thyroid is related to the 5th chakra, or center of communication located around the throat. It is good to keep in mind that the element associated with the 5th chakra is ether. Technically speaking all of our chakras are rooted on the subtle plane of the ethers and bridge the vital gap into physical manifestation. But the 5th chakra is of much interest to etheric relations. It makes one ponder upon the etheric implications of under active and over active 5th chakras.
The human thyroid is the gland that is very closely associated with metabolism. “A primary role of the thyroid is to increase energy expenditure and thermo-genesis.”
That being said the pituitary gland, (or Master Gland,) is responsible for stimulating the thyroid hormone secretion. An imbalance in the thyroid or pituitary gland can lead to challenges in the system.
Hypothyroidism- Underactive thyroid
This implies an individual has thyroid hormone levels that are too low for proper flow in the endocrine system. A common cause of this is the presence of antithyroid antibodies. A common symptom of this is sluggishness, (yoga helps make the body move.)
Hyperthyrodism- Overactive thyroid
This implies that an individual has thyroid levels that are higher than appropriate for the proper flow of energy. There are technically 2 types of this disorder, the type that is caused from within the body and the type that is caused from outside of the body. A common symptom of this is weight loss. This dis-ease can also lead to increased speed in mental processes, but with the propensity to create errors within the thinking. Again, one cause of this is a mis-aligned anti body within the system.
Preventative Thyroid Maintenance
It is my thinking that Yoga, (I am partial to Kundalini but all forms of Yoga are appropriate,) is the optimal means of preventing thyroid disease and disorders. It’s kind of like a car, one takes in their car on a regular basis so that maintenance work can be done. The result of this maintenance is a car that runs smoother, lasts longer and is less likely to die on you. The same is true of the human body and they thyroid.
Kundalini Yoga provides lovely specific means to maintain proper balance within the thyroid. The best way to cure thyroid disease is to never allow the root cause to develop in the first place, thus I stress maintenance.
Food that nurtures the Thyroid
Eating the right foods is also important for proper flow through the thyroid. Mark Hyman M.D. has noticed that thyroid disorders are on the rise, and he brings an interesting and valid perspective as to the cause. He focuses more on the environmental and dietary factors that enter into the thyroid system:
“For example, food allergies, like sensitivities to gluten and other foods, also negatively affect thyroid function-and are frequently undiagnosed. Likewise, deficiencies in nutrients important to good thyroid function-like selenium, zinc, omega-3 fatty acids. and iodine and tyrosine-can trigger thyroid problems.”
Fight Thyroid Disease
Mark Hyman has very sound tips for fighting thyroid disease. I would suggest that we focus on preventing them in the first place.
But if you find yourself in a situation where you need to fight the dis-ease review his suggestions and might I suggest integrating a strong Kundalini Yoga practice into your life cycle.
I have another future proposed test for testing the validity of healing via chakra-neuroendocrinology. There are a couple tests that can be done to measure the levels of thyroid hormones in ones system. I propose a controlled test with 3 groups:
Group of people with over active thyroid (n=60)
Group of peoplw with under active thyroid (n=60)
Control group (n=60)
Measure the levels of thyroid hormone prior to testing. One half of each group will live out their lives normally, or under go the typical Western treatment. The second half will practice Kundalini Yoga on a Daily basis with a strong focus on 5th chakra exercizes and a little 6th chakra work here and ther. (We could add thyroid specific eating into the equation at a future date perhaps.)
I find it interesting that one of my first major energetic blockages in this life time, that I was consciously aware of, was in my throat center. (Sarah, thanks again for the release.)
The timing of this post is also rather interesting, as I am 18 days into a 40 Kundalini Yoga kriya that focuses on the 5th chakra.
Sixth Chakra- Ajna (
Center of Intution or Third Eye)
The ajna center is located directly in ones brow, between the eyebrows on the forehead. This center is commonly called the Third eye. As the third eye opens one is able to access their intuition at a much higher level.
The sixth chakra is also provides a channel for projection of energy, more specifically thought energy. As one starts actively working with the Third Eye sensations, or impressions, begin to register with the conscious mind right in the forehead. One may speak of it as reinforcing ones forehead
When there is not sufficient energy flowing into this center one will have challenges projecting their thoughts into the world of manifestation. They will also have difficulties with their sense of intuition.
People that have an overactive Third Eye may be too mental in nature. They can focus too much of their attention within their own mind and can come off as aloof.
The color of the 6th chakra is a blend of electric blue meets deep purple.
Benefits of a Balanced 6th Chakra
Improved intuition
Ability to swiftly transition into a meditative state
Psychic ability
Thought projection into manifestation
The sixth chakra has much potential to increase the quality of our lives when properly balanced. As humanity evolves the power of the sixth center will be with us. The ability to focus within the mind and bring down impressions from above is truly inspiring
Seventh Chakra- Sahasrara- Crown
The 7th chakra is our connection to the divine. It has been called the thousand petal lotus by many. The seventh center is located at the top of ones head, where the soft spot is located on a baby. It is from this center that we are connected to our souls, and all souls, through the rainbow bridge.
The color of the seventh chakra is light purple, or violet. It is also closely associated with white, or divine, light from above.
Yoga, is a study of Union. It can be said that Kundalini Yoga focuses on the union and balance of the 1st chakra flowing up through the etheric system and merging in the crown chakra.
When the seventh chakra is blocked it impeeds the flow of divine light to flow through our being. It becomes challenging for us to aknowledge the divine within all forms, (Sat Nam, Namaste.) Our relationship with G.O.D is not centered. For those of you who science of prime importance, Generating Energy, Organizing Energy and Destroying/Delivering Energy.
Those with an overactive crown chakra that is not balanced across the heart center may be prone to being not of the world from time to time. Flighty, or aloof come to mind. One that is properly centered is able to operate in the world, but not be of the world.
Benefits of a balanced 7th Chakra
Connection with ones soul
Ability to realize soul purpose
Meditative prowless
Aknowledgement of the divine within all form
Close relationship with G.O.D.
Knowing and walking ones path
The crown chakra represents a location of great spiritual potential. But this is not the only focus of Yoga. All things must come to balance. While participating on the earth school the energies of the 7th center and the connection with the soul must merge with the rest of our being. And from this union peace may be known
NERVOUS SYSTEM
THE NERVOUS SYSTEM
The Neuron |Nervous tissue is composed of two main cell types: neurons and glial cells. Neurons transmit nerve messages. Glial cells are in direct contact with neurons and often surround them.
Nerve Cells and Astrocyte (SEM x2,250). This image is copyright Dennis Kunkel at www.DennisKunkel.com, used with permission.
The neuron is the functional unit of the nervous system. Humans have about 100 billion neurons in their brain alone! While variable in size and shape, all neurons have three parts. Dendrites receive information from another cell and transmit the message to the cell body. The cell body contains the nucleus, mitochondria and other organelles typical of eukaryotic cells. The axon conducts messages away from the cell body.
Structure of a typical neuron.
Three types of neurons occur. Sensory neurons typically have a long dendrite and short axon, and carry messages from sensory receptors to the central nervous system. Motor neurons have a long axon and short dendrites and transmit messages from the central nervous system to the muscles (or to glands). Interneurons are found only in the central nervous system where they connect neuron to neuron.
Structure of a neuron and the direction of nerve message transmission. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Some axons are wrapped in a myelin sheath formed from the plasma membranes of specialized glial cells known as Schwann cells. Schwann cells serve as supportive, nutritive, and service facilities for neurons. The gap between Schwann cells is known as the node of Ranvier, and serves as points along the neuron for generating a signal. Signals jumping from node to node travel hundreds of times faster than signals traveling along the surface of the axon. This allows your brain to communicate with your toes in a few thousandths of a second.
Cross section of myelin sheaths that surround axons (TEM x191,175). This image is copyright Dennis Kunkel at www.DennisKunkel.com, used with permission.
The Nerve Message
The plasma membrane of neurons, like all other cells, has an unequal distribution of ions and electrical charges between the two sides of the membrane. The outside of the membrane has a positive charge, inside has a negative charge. This charge difference is a resting potential and is measured in millivolts. Passage of ions across the cell membrane passes the electrical charge along the cell. The voltage potential is -65mV (millivolts) of a cell at rest (resting potential). Resting potential results from differences between sodium and potassium positively charged ions and negatively charged ions in the cytoplasm. Sodium ions are more concentrated outside the membrane, while potassium ions are more concentrated inside the membrane. This imbalance is maintained by the active transport of ions to reset the membrane known as the sodium potassium pump. The sodium-potassium pump maintains this unequal concentration by actively transporting ions against their concentration gradients.
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Nervous Systems
Multicellular animals must monitor and maintain a constant internal environment as well as monitor and respond to an external environment. In many animals, these two functions are coordinated by two integrated and coordinated organ systems: the nervous system and the endocrine system. Click here for a diagram of the Nervous System.
Three basic functions are prformed by nervous systems:
Receive sensory input from internal and external environments
Integrate the input
Respond to stimuli
Sensory Input
Receptors are parts of the nervous system that sense changes in the internal or external environments. Sensory input can be in many forms, including pressure, taste, sound, light, blood pH, or hormone levels, that are converted to a signal and sent to the brain or spinal cord.
Integration and Output
In the sensory centers of the brain or in the spinal cord, the barrage of input is integrated and a response is generated. The response, a motor output, is a signal transmitted to organs than can convert the signal into some form of action, such as movement, changes in heart rate, release of hormones, etc.
Endocrine Systems
Some animals have a second control system, the endocrine system. The nervous system coordinates rapid responses to external stimuli. The endocrine system controls slower, longer lasting responses to internal stimuli. Activity of both systems is integrated.
Divisions of the Nervous System
The nervous system monitors and controls almost every organ system through a series of positive and negative feedback loops.The Central Nervous System (CNS) includes the brain and spinal cord. The Peripheral Nervous System (PNS) connects the CNS to other parts of the body, and is composed of nerves (bundles of neurons).
Not all animals have highly specialized nervous systems. Those with simple systems tend to be either small and very mobile or large and immobile. Large, mobile animals have highly developed nervous systems: the evolution of nervous systems must have been an important adaptation in the evolution of body size and mobility.
Coelenterates, cnidarians, and echinoderms have their neurons organized into a nerve net. These creatures have radial symmetry and lack a head. Although lacking a brain or either nervous system (CNS or PNS) nerve nets are capable of some complex behavior.
Nervous systems in radially symmetrical animals. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Bilaterally symmetrical animals have a body plan that includes a defined head and a tail region. Development of bilateral symmetry is associated with cephalization, the development of a head with the accumulation of sensory organs at the front end of the organism. Flatworms have neurons associated into clusters known as ganglia, which in turn form a small brain. Vertebrates have a spinal cord in addition to a more developed brain.
Some nervous systems in bilaterally symmetrical animals. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Chordates have a dorsal rather than ventral nervous system. Several evolutionary trends occur in chordates: spinal cord, continuation of cephalization in the form of larger and more complex brains, and development of a more elaborate nervous system. The vertebrate nervous system is divided into a number of parts. The central nervous system includes the brain and spinal cord. The peripheral nervous system consists of all body nerves. Motor neuron pathways are of two types: somatic (skeletal) and autonomic (smooth muscle, cardiac muscle, and glands). The autonomic system is subdivided into the sympathetic and parasympathetic systems.
Peripheral Nervous System
The Peripheral Nervous System (PNS)contains only nerves and connects the brain and spinal cord (CNS) to the rest of the body. The axons and dendrites are surrounded by a white myelin sheath. Cell bodies are in the central nervous system (CNS) or ganglia. Ganglia are collections of nerve cell bodies. Cranial nerves in the PNS take impulses to and from the brain (CNS). Spinal nerves take impulses to and away from the spinal cord. There are two major subdivisions of the PNS motor pathways: the somatic and the autonomic.
Two main components of the PNS:
sensory (afferent) pathways that provide input from the body into the CNS.
motor (efferent) pathways that carry signals to muscles and glands (effectors).
Most sensory input carried in the PNS remains below the level of conscious awareness. Input that does reach the conscious level contributes to perception of our external environment.
Somatic Nervous System | Back to Top
The Somatic Nervous System (SNS) includes all nerves controlling the muscular system and external sensory receptors. External sense organs (including skin) are receptors. Muscle fibers and gland cells are effectors. The reflex arc is an automatic, involuntary reaction to a stimulus. When the doctor taps your knee with the rubber hammer, she/he is testing your reflex (or knee-jerk). The reaction to the stimulus is involuntary, with the CNS being informed but not consciously controlling the response. Examples of reflex arcs include balance, the blinking reflex, and the stretch reflex.
Sensory input from the PNS is processed by the CNS and responses are sent by the PNS from the CNS to the organs of the body.
Motor neurons of the somatic system are distinct from those of the autonomic system. Inhibitory signals, cannot be sent through the motor neurons of the somatic system.
Autonomic Nervous System
The Autonomic Nervous System is that part of PNS consisting of motor neurons that control internal organs. It has two subsystems. The autonomic system controls muscles in the heart, the smooth muscle in internal organs such as the intestine, bladder, and uterus. The Sympathetic Nervous System is involved in the fight or flight response. The Parasympathetic Nervous System is involved in relaxation. Each of these subsystems operates in the reverse of the other (antagonism). Both systems innervate the same organs and act in opposition to maintain homeostasis. For example: when you are scared the sympathetic system causes your heart to beat faster; the parasympathetic system reverses this effect.
Motor neurons in this system do not reach their targets directly (as do those in the somatic system) but rather connect to a secondary motor neuron which in turn innervates the target organ.
Central Nervous System
The Central Nervous System (CNS) is composed of the brain and spinal cord. The CNS is surrounded by bone-skull and vertebrae. Fluid and tissue also insulate the brain and spinal cord.
Areas of the brain. The above image is from http://www.prs.k12.nj.us/schools/PHS/Science_Dept/APBio/pic/brain.gif.
The brain is composed of three parts:
the cerebrum (seat of consciousness), the cerebellum, and the medulla oblongata (these latter two are "part of the unconscious brain").
The medulla oblongata is closest to the spinal cord, and is involved with the regulation of heartbeat, breathing, vasoconstriction (blood pressure), and reflex centers for vomiting, coughing, sneezing, swallowing, and hiccuping. The hypothalamus regulates homeostasis. It has regulatory areas for thirst, hunger, body temperature, water balance, and blood pressure, and links the Nervous System to the Endocrine System. The midbrain and pons are also part of the unconscious brain. The thalamus serves as a central relay point for incoming nervous messages.
The cerebellum is the second largest part of the brain, after the cerebrum. It functions for muscle coordination and maintains normal muscle tone and posture. The cerebellum coordinates balance.
The conscious brain includes the cerebral hemispheres, which are are separated by the corpus callosum. In reptiles, birds, and mammals, the cerebrum coordinates sensory data and motor functions. The cerebrum governs intelligence and reasoning, learning and memory. While the cause of memory is not yet definitely known, studies on slugs indicate learning is accompanied by a synapse decrease. Within the cell, learning involves change in gene regulation and increased ability to secrete transmitters.
The Brain
During embryonic development, the brain first forms as a tube, the anterior end of which enlarges into three hollow swellings that form the brain, and the posterior of which develops into the spinal cord. Some parts of the brain have changed little during vertebrate evolutionary history. Click here to view an diagram of the brain, and here for a clickable map of the brain.
Parts of the brain as seen from the middle of the brain. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Vertebrate evolutionary trends include
Increase in brain size relative to body size.
Subdivision and increasing specialization of the forebrain, midbrain, and hindbrain.
Growth in relative size of the forebrain, especially the cerebrum, which is associated with increasingly complex behavior in mammals.
The Brain Stem and Midbrain
The brain stem is the smallest and from an evolutionary viewpoint, the oldest and most primitive part of the brain. The brain stem is continuous with the spinal cord, and is composed of the parts of the hindbrain and midbrain. The medulla oblongata and pons control heart rate, constriction of blood vessels, digestion and respiration.
The midbrain consists of connections between the hindbrain and forebrain. Mammals use this part of the brain only for eye reflexes.
The Cerebellum
The cerebellum is the third part of the hindbrain, but it is not considered part of the brain stem. Functions of the cerebellum include fine motor coordination and body movement, posture, and balance. This region of the brain is enlarged in birds and controls muscle action needed for flight.
The Forebrain
The forebrain consists of the diencephalon and cerebrum. The thalamus and hypothalamus are the parts of the diencephalon. The thalamus acts as a switching center for nerve messages. The hypothalamus is a major homeostatic center having both nervous and endocrine functions.
The cerebrum,
the largest part of the human brain, is divided into left and right hemispheres connected to each other by the corpus callosum. The hemispheres are covered by a thin layer of gray matter known as the cerebral cortex, the most recently evolved region of the vertebrate brain. Fish have no cerebral cortex, amphibians and reptiles have only rudiments of this area.
The cortex in each hemisphere of the cerebrum is between 1 and 4 mm thick. Folds divide the cortex into four lobes: occipital, temporal, parietal, and frontal. No region of the brain functions alone, although major functions of various parts of the lobes have been determined.
The major brain areas and lobes. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The occipital lobe (back of the head) receives and processes visual information. The temporal lobe receives auditory signals, processing language and the meaning of words. The parietal lobe is associated with the sensory cortex and processes information about touch, taste, pressure, pain, and heat and cold. The frontal lobe conducts three functions:
motor activity and integration of muscle activity
speech
thought processes
Functional areas of the brain. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Most people who have been studied have their language and speech areas on the left hemisphere of their brain. Language comprehension is found in Wernicke's area. Speaking ability is in Broca's area. Damage to Broca's area causes speech impairment but not impairment of language comprehension. Lesions in Wernicke's area impairs ability to comprehend written and spoken words but not speech. The remaining parts of the cortex are associated with higher thought processes, planning, memory, personality and other human activities.
Parts of the cerebral cortex and the relative areas that are devoted to controlling various body regions. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The Spinal Cord
The spinal cord runs along the dorsal side of the body and links the brain to the rest of the body. Vertebrates have their spinal cords encased in a series of (usually) bony vertebrae that comprise the vertebral column.
The gray matter of the spinal cord consists mostly of cell bodies and dendrites. The surrounding white matter is made up of bundles of interneuronal axons (tracts). Some tracts are ascending (carrying messages to the brain), others are descending (carrying messages from the brain). The spinal cord is also involved in reflexes that do not immediately involve the brain.
The Brain and Drugs
Some neurotransmitters are excitory, such as acetylcholine, norepinephrine, serotonin, and dopamine. Some are associated with relaxation, such as dopamine and serotonin. Dopamine release seems related to sensations of pleasure. Endorphins are natural opioids that produce elation and reduction of pain, as do artificial chemicals such as opium and heroin. Neurological diseases, for example Parkinson's disease and Huntington's disease, are due to imbalances of neurotransmitters. Parkinson's is due to a dopamine deficiency. Huntington's disease is thought to be cause by malfunctioning of an inhibitory neurotransmitter. Alzheimer's disease is associated with protein plaques in the brain.
Drugs are stimulants or depressants that block or enhance certain neurotransmitters. Dopamine is thought involved with all forms of pleasure. Cocaine interferes with uptake of dopamine from the synaptic cleft. Alcohol causes a euphoric "high" followed by a depression.
Marijuana, material from the Indian hemp plant (Cannabis sativa), has a potent chemical THC (tetrahydracannibinol) that in low, concentrations causes a euphoric high (if inhaled, the most common form of action is smoke inhalation). High dosages may cause severe effects such as hallucinations, anxiety, depression, and psychotic symptoms.
Cocaine is derives from the plant Erthoxylon coca. Inhaled, smoked or injected. Cocaine users report a "rush" of euphoria following use. Following the rush is a short (5-30 minute) period of arousal followed by a depression. Repeated cycle of use terminate in a "crash" when the cocaine is gone. Prolonged used causes production of less dopamine, causing the user to need more of the drug.
Heroin is a derivative of morphine, which in turn is obtained from opium, the milky secretions obtained from the opium poppy, Papaver somniferum. Heroin is usually injected intravenously, although snorting and smoking serve as alternative delivery methods. Heroin binds to ophioid receptors in the brain, where the natural chemical endorphins are involved in the cessation pain. Heroin is physically addictive, and prolonged use causes less endorphin production. Once this happens, the euphoria is no longer felt, only dependence and delay of withdrawal symptoms.
Senses
Input to the nervous system is in the form of our five senses: pain, vision, taste, smell, and hearing. Vision, taste, smell, and hearing input are the special senses. Pain, temperature, and pressure are known as somatic senses. Sensory input begins with sensors that react to stimuli in the form of energy that is transmitted into an action potential and sent to the CNS.
Sensory Receptors
Sensory receptors are classified according to the type of energy they can detect and respond to.
Mechanoreceptors: hearing and balance, stretching.
Photoreceptors: light.
Chemoreceptors: smell and taste mainly, as well as internal sensors in the digestive and circulatory systems.
Thermoreceptors: changes in temperature.
Electroreceptors: detect electrical currents in the surrounding environment.
Mechanoreceptors vary greatly in the specific type of stimulus and duration of stimulus/action potentials. The most adaptable vertebrate mechanoreceptor is the hair cell. Hair cells are present in the lateral line of fish. In humans and mammals hair cells are involved with detection of sound and gravity and providing balance.
Hearing
Hearing involves the actions of the external ear, eardrum, ossicles, and cochlea. In hearing, sound waves in air are converted into vibrations of a liquid then into movement of hair cells in the cochlea. Finally they are converted into action potentials in a sensory dendrite connected to the auditory nerve. Very loud sounds can cause violent vibrations in the membrane under hair cells, causing a shearing or permanent distortion to the cells, resulting in permanent hearing loss.
Orientation and Gravity
Orientation and gravity are detected at the semicircular canals. Hair cells along three planes respond to shifts of liquid within the cochlea, providing a three-dimensional sense of equilibrium. Calcium carbonate crystals can shift in response to gravity, providing sensory information about gravity and acceleration.
Photoreceptors Detect Vision and Light Sensitivity
The human eye can detect light in the 400-700 nanometer (nm) range, a small portion of the electromagnetic spectrum, the visible light spectrum. Light with wavelengths shorter than 400 nm is termed ultraviolet (UV) light. Light with wavelengths longer than 700 nm is termed infrared (IR) light.
The electromagnetic spectrum. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Eye
In the eye, two types of photoreceptor cells are clustered on the retina, or back portion of the eye. These receptors, rods and cones, apparently evolved from hair cells. Rods detect differences in light intensity; cones detect color. Rods are more common in a circular zone near the edge of the eye. Cones occur in the center (or fovea centralis) of the retina.
Light reaching a photoreceptor causes the breakdown of the chemical rhodopsin, which in turn causes a membrane potential that is transmitted to an action potential. The action potential transfers to synapsed neurons that connect to the optic nerve. The optic nerve connects to the occipital lobe of the brain.
Humans have three types of cones, each sensitive to a different color of light: red, blue and green. Opsins are chemicals that bind to cone cells and make those cells sensitive to light of a particular wavelength (or color). Humans have three different form of opsins coded for by three genes on the X chromosome. Defects in one or more of these opsin genes can cause color blindness, usually in males.
Links | Back to Top
Nervous System Java Animation Net Doctor...you will need a Java-enabled browser to view the animation or you can download the AVI file.
Parkinson's Disease Information Page
Clickable Map of the Brain
The Neuron |Nervous tissue is composed of two main cell types: neurons and glial cells. Neurons transmit nerve messages. Glial cells are in direct contact with neurons and often surround them.
Nerve Cells and Astrocyte (SEM x2,250). This image is copyright Dennis Kunkel at www.DennisKunkel.com, used with permission.
The neuron is the functional unit of the nervous system. Humans have about 100 billion neurons in their brain alone! While variable in size and shape, all neurons have three parts. Dendrites receive information from another cell and transmit the message to the cell body. The cell body contains the nucleus, mitochondria and other organelles typical of eukaryotic cells. The axon conducts messages away from the cell body.
Structure of a typical neuron.
Three types of neurons occur. Sensory neurons typically have a long dendrite and short axon, and carry messages from sensory receptors to the central nervous system. Motor neurons have a long axon and short dendrites and transmit messages from the central nervous system to the muscles (or to glands). Interneurons are found only in the central nervous system where they connect neuron to neuron.
Structure of a neuron and the direction of nerve message transmission. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Some axons are wrapped in a myelin sheath formed from the plasma membranes of specialized glial cells known as Schwann cells. Schwann cells serve as supportive, nutritive, and service facilities for neurons. The gap between Schwann cells is known as the node of Ranvier, and serves as points along the neuron for generating a signal. Signals jumping from node to node travel hundreds of times faster than signals traveling along the surface of the axon. This allows your brain to communicate with your toes in a few thousandths of a second.
Cross section of myelin sheaths that surround axons (TEM x191,175). This image is copyright Dennis Kunkel at www.DennisKunkel.com, used with permission.
The Nerve Message
The plasma membrane of neurons, like all other cells, has an unequal distribution of ions and electrical charges between the two sides of the membrane. The outside of the membrane has a positive charge, inside has a negative charge. This charge difference is a resting potential and is measured in millivolts. Passage of ions across the cell membrane passes the electrical charge along the cell. The voltage potential is -65mV (millivolts) of a cell at rest (resting potential). Resting potential results from differences between sodium and potassium positively charged ions and negatively charged ions in the cytoplasm. Sodium ions are more concentrated outside the membrane, while potassium ions are more concentrated inside the membrane. This imbalance is maintained by the active transport of ions to reset the membrane known as the sodium potassium pump. The sodium-potassium pump maintains this unequal concentration by actively transporting ions against their concentration gradients.
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Nervous Systems
Multicellular animals must monitor and maintain a constant internal environment as well as monitor and respond to an external environment. In many animals, these two functions are coordinated by two integrated and coordinated organ systems: the nervous system and the endocrine system. Click here for a diagram of the Nervous System.
Three basic functions are prformed by nervous systems:
Receive sensory input from internal and external environments
Integrate the input
Respond to stimuli
Sensory Input
Receptors are parts of the nervous system that sense changes in the internal or external environments. Sensory input can be in many forms, including pressure, taste, sound, light, blood pH, or hormone levels, that are converted to a signal and sent to the brain or spinal cord.
Integration and Output
In the sensory centers of the brain or in the spinal cord, the barrage of input is integrated and a response is generated. The response, a motor output, is a signal transmitted to organs than can convert the signal into some form of action, such as movement, changes in heart rate, release of hormones, etc.
Endocrine Systems
Some animals have a second control system, the endocrine system. The nervous system coordinates rapid responses to external stimuli. The endocrine system controls slower, longer lasting responses to internal stimuli. Activity of both systems is integrated.
Divisions of the Nervous System
The nervous system monitors and controls almost every organ system through a series of positive and negative feedback loops.The Central Nervous System (CNS) includes the brain and spinal cord. The Peripheral Nervous System (PNS) connects the CNS to other parts of the body, and is composed of nerves (bundles of neurons).
Not all animals have highly specialized nervous systems. Those with simple systems tend to be either small and very mobile or large and immobile. Large, mobile animals have highly developed nervous systems: the evolution of nervous systems must have been an important adaptation in the evolution of body size and mobility.
Coelenterates, cnidarians, and echinoderms have their neurons organized into a nerve net. These creatures have radial symmetry and lack a head. Although lacking a brain or either nervous system (CNS or PNS) nerve nets are capable of some complex behavior.
Nervous systems in radially symmetrical animals. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Bilaterally symmetrical animals have a body plan that includes a defined head and a tail region. Development of bilateral symmetry is associated with cephalization, the development of a head with the accumulation of sensory organs at the front end of the organism. Flatworms have neurons associated into clusters known as ganglia, which in turn form a small brain. Vertebrates have a spinal cord in addition to a more developed brain.
Some nervous systems in bilaterally symmetrical animals. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Chordates have a dorsal rather than ventral nervous system. Several evolutionary trends occur in chordates: spinal cord, continuation of cephalization in the form of larger and more complex brains, and development of a more elaborate nervous system. The vertebrate nervous system is divided into a number of parts. The central nervous system includes the brain and spinal cord. The peripheral nervous system consists of all body nerves. Motor neuron pathways are of two types: somatic (skeletal) and autonomic (smooth muscle, cardiac muscle, and glands). The autonomic system is subdivided into the sympathetic and parasympathetic systems.
Peripheral Nervous System
The Peripheral Nervous System (PNS)contains only nerves and connects the brain and spinal cord (CNS) to the rest of the body. The axons and dendrites are surrounded by a white myelin sheath. Cell bodies are in the central nervous system (CNS) or ganglia. Ganglia are collections of nerve cell bodies. Cranial nerves in the PNS take impulses to and from the brain (CNS). Spinal nerves take impulses to and away from the spinal cord. There are two major subdivisions of the PNS motor pathways: the somatic and the autonomic.
Two main components of the PNS:
sensory (afferent) pathways that provide input from the body into the CNS.
motor (efferent) pathways that carry signals to muscles and glands (effectors).
Most sensory input carried in the PNS remains below the level of conscious awareness. Input that does reach the conscious level contributes to perception of our external environment.
Somatic Nervous System | Back to Top
The Somatic Nervous System (SNS) includes all nerves controlling the muscular system and external sensory receptors. External sense organs (including skin) are receptors. Muscle fibers and gland cells are effectors. The reflex arc is an automatic, involuntary reaction to a stimulus. When the doctor taps your knee with the rubber hammer, she/he is testing your reflex (or knee-jerk). The reaction to the stimulus is involuntary, with the CNS being informed but not consciously controlling the response. Examples of reflex arcs include balance, the blinking reflex, and the stretch reflex.
Sensory input from the PNS is processed by the CNS and responses are sent by the PNS from the CNS to the organs of the body.
Motor neurons of the somatic system are distinct from those of the autonomic system. Inhibitory signals, cannot be sent through the motor neurons of the somatic system.
Autonomic Nervous System
The Autonomic Nervous System is that part of PNS consisting of motor neurons that control internal organs. It has two subsystems. The autonomic system controls muscles in the heart, the smooth muscle in internal organs such as the intestine, bladder, and uterus. The Sympathetic Nervous System is involved in the fight or flight response. The Parasympathetic Nervous System is involved in relaxation. Each of these subsystems operates in the reverse of the other (antagonism). Both systems innervate the same organs and act in opposition to maintain homeostasis. For example: when you are scared the sympathetic system causes your heart to beat faster; the parasympathetic system reverses this effect.
Motor neurons in this system do not reach their targets directly (as do those in the somatic system) but rather connect to a secondary motor neuron which in turn innervates the target organ.
Central Nervous System
The Central Nervous System (CNS) is composed of the brain and spinal cord. The CNS is surrounded by bone-skull and vertebrae. Fluid and tissue also insulate the brain and spinal cord.
Areas of the brain. The above image is from http://www.prs.k12.nj.us/schools/PHS/Science_Dept/APBio/pic/brain.gif.
The brain is composed of three parts:
the cerebrum (seat of consciousness), the cerebellum, and the medulla oblongata (these latter two are "part of the unconscious brain").
The medulla oblongata is closest to the spinal cord, and is involved with the regulation of heartbeat, breathing, vasoconstriction (blood pressure), and reflex centers for vomiting, coughing, sneezing, swallowing, and hiccuping. The hypothalamus regulates homeostasis. It has regulatory areas for thirst, hunger, body temperature, water balance, and blood pressure, and links the Nervous System to the Endocrine System. The midbrain and pons are also part of the unconscious brain. The thalamus serves as a central relay point for incoming nervous messages.
The cerebellum is the second largest part of the brain, after the cerebrum. It functions for muscle coordination and maintains normal muscle tone and posture. The cerebellum coordinates balance.
The conscious brain includes the cerebral hemispheres, which are are separated by the corpus callosum. In reptiles, birds, and mammals, the cerebrum coordinates sensory data and motor functions. The cerebrum governs intelligence and reasoning, learning and memory. While the cause of memory is not yet definitely known, studies on slugs indicate learning is accompanied by a synapse decrease. Within the cell, learning involves change in gene regulation and increased ability to secrete transmitters.
The Brain
During embryonic development, the brain first forms as a tube, the anterior end of which enlarges into three hollow swellings that form the brain, and the posterior of which develops into the spinal cord. Some parts of the brain have changed little during vertebrate evolutionary history. Click here to view an diagram of the brain, and here for a clickable map of the brain.
Parts of the brain as seen from the middle of the brain. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Vertebrate evolutionary trends include
Increase in brain size relative to body size.
Subdivision and increasing specialization of the forebrain, midbrain, and hindbrain.
Growth in relative size of the forebrain, especially the cerebrum, which is associated with increasingly complex behavior in mammals.
The Brain Stem and Midbrain
The brain stem is the smallest and from an evolutionary viewpoint, the oldest and most primitive part of the brain. The brain stem is continuous with the spinal cord, and is composed of the parts of the hindbrain and midbrain. The medulla oblongata and pons control heart rate, constriction of blood vessels, digestion and respiration.
The midbrain consists of connections between the hindbrain and forebrain. Mammals use this part of the brain only for eye reflexes.
The Cerebellum
The cerebellum is the third part of the hindbrain, but it is not considered part of the brain stem. Functions of the cerebellum include fine motor coordination and body movement, posture, and balance. This region of the brain is enlarged in birds and controls muscle action needed for flight.
The Forebrain
The forebrain consists of the diencephalon and cerebrum. The thalamus and hypothalamus are the parts of the diencephalon. The thalamus acts as a switching center for nerve messages. The hypothalamus is a major homeostatic center having both nervous and endocrine functions.
The cerebrum,
the largest part of the human brain, is divided into left and right hemispheres connected to each other by the corpus callosum. The hemispheres are covered by a thin layer of gray matter known as the cerebral cortex, the most recently evolved region of the vertebrate brain. Fish have no cerebral cortex, amphibians and reptiles have only rudiments of this area.
The cortex in each hemisphere of the cerebrum is between 1 and 4 mm thick. Folds divide the cortex into four lobes: occipital, temporal, parietal, and frontal. No region of the brain functions alone, although major functions of various parts of the lobes have been determined.
The major brain areas and lobes. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The occipital lobe (back of the head) receives and processes visual information. The temporal lobe receives auditory signals, processing language and the meaning of words. The parietal lobe is associated with the sensory cortex and processes information about touch, taste, pressure, pain, and heat and cold. The frontal lobe conducts three functions:
motor activity and integration of muscle activity
speech
thought processes
Functional areas of the brain. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Most people who have been studied have their language and speech areas on the left hemisphere of their brain. Language comprehension is found in Wernicke's area. Speaking ability is in Broca's area. Damage to Broca's area causes speech impairment but not impairment of language comprehension. Lesions in Wernicke's area impairs ability to comprehend written and spoken words but not speech. The remaining parts of the cortex are associated with higher thought processes, planning, memory, personality and other human activities.
Parts of the cerebral cortex and the relative areas that are devoted to controlling various body regions. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
The Spinal Cord
The spinal cord runs along the dorsal side of the body and links the brain to the rest of the body. Vertebrates have their spinal cords encased in a series of (usually) bony vertebrae that comprise the vertebral column.
The gray matter of the spinal cord consists mostly of cell bodies and dendrites. The surrounding white matter is made up of bundles of interneuronal axons (tracts). Some tracts are ascending (carrying messages to the brain), others are descending (carrying messages from the brain). The spinal cord is also involved in reflexes that do not immediately involve the brain.
The Brain and Drugs
Some neurotransmitters are excitory, such as acetylcholine, norepinephrine, serotonin, and dopamine. Some are associated with relaxation, such as dopamine and serotonin. Dopamine release seems related to sensations of pleasure. Endorphins are natural opioids that produce elation and reduction of pain, as do artificial chemicals such as opium and heroin. Neurological diseases, for example Parkinson's disease and Huntington's disease, are due to imbalances of neurotransmitters. Parkinson's is due to a dopamine deficiency. Huntington's disease is thought to be cause by malfunctioning of an inhibitory neurotransmitter. Alzheimer's disease is associated with protein plaques in the brain.
Drugs are stimulants or depressants that block or enhance certain neurotransmitters. Dopamine is thought involved with all forms of pleasure. Cocaine interferes with uptake of dopamine from the synaptic cleft. Alcohol causes a euphoric "high" followed by a depression.
Marijuana, material from the Indian hemp plant (Cannabis sativa), has a potent chemical THC (tetrahydracannibinol) that in low, concentrations causes a euphoric high (if inhaled, the most common form of action is smoke inhalation). High dosages may cause severe effects such as hallucinations, anxiety, depression, and psychotic symptoms.
Cocaine is derives from the plant Erthoxylon coca. Inhaled, smoked or injected. Cocaine users report a "rush" of euphoria following use. Following the rush is a short (5-30 minute) period of arousal followed by a depression. Repeated cycle of use terminate in a "crash" when the cocaine is gone. Prolonged used causes production of less dopamine, causing the user to need more of the drug.
Heroin is a derivative of morphine, which in turn is obtained from opium, the milky secretions obtained from the opium poppy, Papaver somniferum. Heroin is usually injected intravenously, although snorting and smoking serve as alternative delivery methods. Heroin binds to ophioid receptors in the brain, where the natural chemical endorphins are involved in the cessation pain. Heroin is physically addictive, and prolonged use causes less endorphin production. Once this happens, the euphoria is no longer felt, only dependence and delay of withdrawal symptoms.
Senses
Input to the nervous system is in the form of our five senses: pain, vision, taste, smell, and hearing. Vision, taste, smell, and hearing input are the special senses. Pain, temperature, and pressure are known as somatic senses. Sensory input begins with sensors that react to stimuli in the form of energy that is transmitted into an action potential and sent to the CNS.
Sensory Receptors
Sensory receptors are classified according to the type of energy they can detect and respond to.
Mechanoreceptors: hearing and balance, stretching.
Photoreceptors: light.
Chemoreceptors: smell and taste mainly, as well as internal sensors in the digestive and circulatory systems.
Thermoreceptors: changes in temperature.
Electroreceptors: detect electrical currents in the surrounding environment.
Mechanoreceptors vary greatly in the specific type of stimulus and duration of stimulus/action potentials. The most adaptable vertebrate mechanoreceptor is the hair cell. Hair cells are present in the lateral line of fish. In humans and mammals hair cells are involved with detection of sound and gravity and providing balance.
Hearing
Hearing involves the actions of the external ear, eardrum, ossicles, and cochlea. In hearing, sound waves in air are converted into vibrations of a liquid then into movement of hair cells in the cochlea. Finally they are converted into action potentials in a sensory dendrite connected to the auditory nerve. Very loud sounds can cause violent vibrations in the membrane under hair cells, causing a shearing or permanent distortion to the cells, resulting in permanent hearing loss.
Orientation and Gravity
Orientation and gravity are detected at the semicircular canals. Hair cells along three planes respond to shifts of liquid within the cochlea, providing a three-dimensional sense of equilibrium. Calcium carbonate crystals can shift in response to gravity, providing sensory information about gravity and acceleration.
Photoreceptors Detect Vision and Light Sensitivity
The human eye can detect light in the 400-700 nanometer (nm) range, a small portion of the electromagnetic spectrum, the visible light spectrum. Light with wavelengths shorter than 400 nm is termed ultraviolet (UV) light. Light with wavelengths longer than 700 nm is termed infrared (IR) light.
The electromagnetic spectrum. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission.
Eye
In the eye, two types of photoreceptor cells are clustered on the retina, or back portion of the eye. These receptors, rods and cones, apparently evolved from hair cells. Rods detect differences in light intensity; cones detect color. Rods are more common in a circular zone near the edge of the eye. Cones occur in the center (or fovea centralis) of the retina.
Light reaching a photoreceptor causes the breakdown of the chemical rhodopsin, which in turn causes a membrane potential that is transmitted to an action potential. The action potential transfers to synapsed neurons that connect to the optic nerve. The optic nerve connects to the occipital lobe of the brain.
Humans have three types of cones, each sensitive to a different color of light: red, blue and green. Opsins are chemicals that bind to cone cells and make those cells sensitive to light of a particular wavelength (or color). Humans have three different form of opsins coded for by three genes on the X chromosome. Defects in one or more of these opsin genes can cause color blindness, usually in males.
Links | Back to Top
Nervous System Java Animation Net Doctor...you will need a Java-enabled browser to view the animation or you can download the AVI file.
Parkinson's Disease Information Page
Clickable Map of the Brain
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