It has generally been observed that we can remain alive for some time without food, for a lesser time without water, but for a very short time without air. The process of inhalation and exhalation continuous unabated from our birth to death. Not many of us are familiar with this important function. This is the basis of our life. The following are the chief organs of our Respiratory System.

  1. Nose
  2. Pharynx
  3. Larynx
  4. Trachea (Note: These four extend up to the lungs)
  5. Bronchial Tubes
  6. Lungs
    1. Bronchioles
    2. Alveolar Tubes (in the Lungs)



  • Nose: There is the small growth of hair inside our nose and the same is intended to prevent the dust-laden air to pass through and get it well filtered before it is inhaled. When the air touches the membrane inside the nose, it first becomes warm and then goes inside. It thus saves the lungs from getting cold suddenly.


  • Pharynx: This is the passage for air through nose or mouth behind the tonsils.
  • Larynx: This is a sound producing organ. It is like a small box. Air passes out through this very organ.
  • Trachea : It is that pipe passing through which the air of the nose reaches the lungs. The upper part of the trachea in the throat somewhat bulging and wide is called larynx. The lower part of it is trachea which is 12cm. long. The chewed food morsel goes into the alimentary canal which is located a little above it & it is covered by a lid over it, fixed in the upper part of trachea. Beyond it, it branches into two parts.
  • Bronchial Tubes: The windpipe extends to a point in the upper part of the chest cavity and thereafter gets bifurcated into two parts. It is known as bronchi. One part goes into the right lung and the other to the left. Thereafter they branch out small twigs and assume the shape of a topsy-turvy tree.
  • Lungs : They are two in number. Each of the two lungs is located on either side of the chest bone in the chest cavity. In between the two, the Heart is located on the left side. The upper part of each lung is somewhat narrow and the lower part somewhat broad. The lower part of the lungs rests on the diaphragm. The lungs have innumerable air sacks. They are spread like the bunches of grapes, which expand and contract like the sponge. Each lung is enveloped by a double membrane like lining called Pleura. In between these layers is a fluid substance that protects the lungs from any hurt, shock or abrasion.



There are pure (Oxygenated) blood vessels and minute veins intended to provide proper nutrition to lungs & maintain their link with the brain. While inhaling the lungs expand in different directions-left, right, upwards and downwards. The right lung is divided into three lobes and the left into two lobes.


The process of breathing can be divided into two part :

  1. Outer-Breath: Mixing of blood with oxygen flowing out of lungs and air-chambers as well as the outflow of carbon-dioxide from the air chambers.
  2. Inner Breath: Oxygen provided by the blood cells & absorption of the same by the body and excretion of carbon-dioxide from inside.

Consequently, chemical reactions take place inside the cells in the form of oxygenation.

Through the medium of above-mentioned processes Pran (Vital energy) goes on entering into our body and it is that energy that makes our movements and actions possible. Pran is different from air & subtler then air. Just as machines are run by the power generated by electricity, similarly the creation and activity of the body remain intact by the force known as Pran.

It is by ‘Yog’ that we can keep this vital energy under control. Through its control starts with Yogasans it is really through Pranayam that we can gain complete mastery Over it.


Circulatory System’s entire function of blood circulation is based upon the respiratory system. The main organs of the Circulatory System are :

  1. Heart
  2. Lungs
  3. Archon Aorta
  4. Arteries
  5. Veins
  6. Capillaries

Our heart is located on the left side in the middle of lungs. It pumps blood into the body through the blood tubules. This process goes on continuously from birth to death. Such a marvelous pump that remains active for at least a hundred years, can hardly be found anywhere in the world. There are three kinds of capillaries (blood carriers)  in our body :

  1. Arteries: They carry pure blood from the heart to the body. The pressure exerted by the contraction of the heart (when it beats) continuous to remain in the arteries.
  2. Veins: They carry impure blood from the body to the heart.
  3. Capillaries: They are extremely subtle in nature. Passing deep into the tissues they are connected with the cells of the body. It is the job of the capillaries to bring with them. Oxygen, nutritive elements, and hormones etc. through the medium of the blood and again to mix with blood such excretory substances as carbon dioxide produced by these cells.

As regards the veins they supply blood to the Auricle located at the right chamber of the heart through the medium of super veins. The oxygenated pure blood reaches the upper chamber, Auricle located in the left side of the heart through the medium of veins in the lungs. Impure blood enters into the right ventricle by opening the one-sided valve of the right chamber and thereafter it reaches the lungs in order to get oxygenated by the arteries of the lungs. At the same time, oxygenated blood pushed into the left ventricle from the left chamber and therefrom into the outer artery.

From the aorta, the pureblood passes through small & big arteries and finally reaches the entire body through the medium of very subtle cells.

Red blood granules that carry oxygen enter micro-capillaries one by one in a line. They supply oxygen to the cells and receive carbon dioxide from them.

Thus there are two main processes of blood circulation :

(1) All round blood circulation i.e. blood circulation taking place in the entire body and

(2) Blood circulation in the lungs: i.e. blood circulation from lungs to the heart & from the heart to the lungs.

Prior to each heart-beat, both the chambers contract and thereafter both the ventricles also contract. As a result, the blood starts flowing out & both the chambers get relaxed. This way they receive the blood from both sides & it is thus that the purification and distribution of blood fake place in our body through the medium of the heart.

For the proper functioning of the heart, it is necessary that it receives a sufficient quantity of blood. As a matter of fact, the heart needs ten times the quantity of blood required by other organs. Ordinarily, the body cells also get their nourishment through the medium of blood that reaches them. It should also be noted that the heart does not get any nourishment from the blood that gathers in large quantity in its chambers and ventricles. There is a special arrangement for the nourishment of the heart. The two coronaries of the heart, branching out of the Aorta pass by its left and right side and rising upwards spread around it in branches and sub-branches. These arteries nourish the entire heart through the medium of blood. If by any reason these arteries are blocked either partially or fully the heart will not receive sufficient quantity of nourishment.

Special Note

Between two beats, the heart takes rest. Yog, therefore, teaches us the technique to increase the duration of rest. Simultaneously by the control of breath and the capacity to make if deeper and deeper, the circulation of blood becomes normal in all parts of the body. Deep breathing is done mainly in three parts of the body.

Breathing up to the upper part of the lungs: With this type of breathing nourishment of blood takes place in our neck, head and hands. Due to the lack of air in this part, the cells of the brain become weak. As a result, deafness, weakness of the eye-sight, headache, tension and such like ailments take place.

In this way, deep breathing can be done only by the person, who practices Yogasans and Panayam every day without fail. This is the real secret of a person who enjoys a sound health and a disease-free life.

In the end, we would like to mention an important point. It is that the expansion and contraction of the heart are caused by Pran, the vital energy in man. Here again, it is possible to control it with the practice of Pranayam only. This vital organ, namely the Heart can be kept healthy by the different practices of Yoga.

Excretory System controls the excretion of waste matter from the body is far more important than the consumption of food. The acid that mixes with the food for its digestion has necessarily to come out after the digestion process is complete. This important function is performed by the kidneys in our body system.

Kidneys: They are located on both sides of the vertebral column in the stomach below the diaphragm. They filter approximately double the quantity of blood in the body in a single day. What is most surprising is that in the process of purification or filtration, red corpuscles (particles) of blood, essential blood proteins, and vitamins, amino acids, glucose, and hormones do not filter from the blood, but are returned to the blood itself. This way the entire waste product goes out of the body through urine in the form of urea and uric acid. Besides this, the important function of the kidneys are :

  • To help the formation of red blood corpuscles.
  • To maintain the balance of water in the body.
  • To prevent too much acidity or alkaline element in the blood.
  • Organs connected with the kidneys are Ureters, Bladder and Urethra.

Prostate Gland: It is located below the bladder. Urethra passes through the mid of this gland. In this gland, there are some glandular tissues & some involuntary muscles. The glandular tissues release a kind of secretion which is supposed to work as a lubricant for spermatozoa.

Seminal Gland: This is located behind the bladder and also called testicles. It has the shape of a bag. It discharges a thick fluid called semen. Yogins do not let it go waste as it is like an invaluable gem in our body. Through the practice of some special Yoga techniques they make it rise upwards.

Besides this, there are many other means by which the waste matter goes on excreting continuously from our body. As a result, our body remains free from disease and health. There are :

  1. Perspiration from the pores of the skin.
  2. The outlet of phlegm from the mouth.
  3. Oozing of dirty fluid from the eyes.
  4. Discharge of foreign matter from the ear and
  5. Waste matter released by the nostrils in the form of bile and carbon dioxide.

Special Note

The excretion capacity of our excretory organs is toned up by Yog, as a result of which no waste matter gets stuck up in the body. Semen in the seminal gland is preserved and converted into ‘Ojas’ (lustre) and Tejas (radiance) on the face of a person.

The main function of the Digestive System is the conversion of food into juices and the distribution of those juices into the body. It makes the body strong whatever foreign matter is left over, goes out of the body by excretion process. The main parts of our digestive system are the following.

Alimentary Canal

These are six salivary glands in the mouth which contrive to produces saliva in the mouth. But prior to this food is chewed with teeth.

Different parts of it are as under :

  1. Mouth
  2. Pharynx
  3. Oesophagus
  4. Stomach
  5. Duodenum
  6. Liver
  7. Pancreas
  8. Gall Bladder
  9. Small Intestine
  10. Caccum
  11. Appendix
  12. Large Intestine
  13. Rectum
  14. Anus

Glands Releasing Digestive Juices

  1. Inside the mouse Salivary Glands
  2. Below and in front of the ear Parotid Glands
  3. Below the jaw Submandibular
  4. Below the tongue Sublingual

Stomach Glands : They release gastric juices in the stomach.

Pancreas Gland : It realizes pancreatic juices from small intestine into the duodenum.

Liver : It release bile into duodenum.

Intestinal Glands : They release intestinal juices into the small intestine.


The Alimentary Canal that spans from the mouth to the kidney is about 9 metres in length. How the food passes through this canal is given as under :

First our food is chewed by our teeth. The salivary glands mix saliva with it & it helps us in swallowing the food easily. The tongue relishes its taste and pushes it into the pharynx. From there it goes into the gullet which is a 25-30 cm. long muscular canal reaching upto the stomach. It stretches from a point in the neck behind trachea (Wind pipe) and in the chest behind trachea and heart (Wind pipe) and in the chest behind trachea and heart. It then goes down passing through the diaphragm upto the cardiac end of the stomach. The stomach is located in the upper part of our abdomen and below the diaphragm. The orifice of the stomach is covered with a thick membrane called sphinker. That is why when we bend, the food does not return to the food pipe (Oesophagus) or back towards the mouth. It happens only when the muscles of the stomach contract vigorously as it happens at the time of vomiting.

The following changes take place when the food goes into the stomach.

  1. Churning of the food, as a result of which it breaks into small pieces and by which process it becomes soft.
  2. Digestion of food with the help of gastric juices.
  3. Secretion of a kind of fluid the sides of the stomach.


From the stomach food goes to the small intestine and there from it is transferred to the large intestine. In the small intestine pancreatic juice, bile and intestine juice mix with the food and make it more digestible. Here the food is more kneaded.

With the process of expansion and contraction of small intestine, proteins, carbohydrates and fats are absorbed i.e. when the food is digested, it release a kind of juice. This juice is transmitted to all the cells of body through the blood veins. The waste material is pushed into the large intestine which is divided into four parts :


  • Asscending Colon : It passes through the right side of the stomach and upper side of Caecum and then reaches the lower layer of the liver.
  • Transverse Colon: It spans from the front part of the abdomen to a point under the left side of the stomach.
  • Descending Colon : Extending downward towards the left side, it reaches upto iliacposa.
  • Sigmoid Flexure : Finally, it makes an ‘O’ shaped curve and reaches the rectum in the pelvic region.

The waste matter is excreted out of the large intestine at its appointed time. This is the last portion of the alimentary canal. Passing from the stomach to the small intestines and therefrom to colon, it takes 6 hours for the food to travel from one place to another. Light food like soft drinks, fruits etc. are digested quickly but it takes about 6 hours for the solid food like bread etc. to digest. This way our body takes 17-18 hours to completely digest the food item. The food juice is extracted from the food by the body and the waste matter is thrown out.

Special Note

Kunjal Kriya is a technique by virtue of which our alimentary canal from the throat to the stomach is completely cleaned. There is another technique of cleaning the bowels known as Shankh-Prakhshalan (Stomach wash). The entire alimentary canal from the throat to anus is washed and cleaned by this process. The different parts of the alimentary canal are influcenced by the various practices of Yogasans.

Agnisar, Bhastrika and Kapal Bhati Pranayam play an important role in the purification of our large and small intestines.


There are certain organs of the body that produce Rasa (Juices). They are known as Glands. They can be divided into two parts according to their demands.

  1. Duct Glands: They produce such secretions as are helpful in the healthy formation of our body. i.e. saliva, bile and pancreatic juice etc.
  2. Endocrine / Ductless Glands: No nerve emerges out of these glands. Blood reaches these glands through the blood vessels in great quantity. The chemical secretions produced by them, pass directly through the walls of the blood cells inside the glands & then mix with the blood. It s through the blood they reach the other parts of the body. Then secretions are called Hormones. These Hormones are vital to the sustenance of the human body.

The glands are located very close to five plexuses in our spinal cord.

  1. Near the Agya Plexus Pineal & Pituitary Glands.
  2. Near the Vishudhi Chakra – Thyroid and Parathyroid Glands.
  3. Near Anahat Chakra – Thymus Gland
  4. Near Manipur Chakra – Adrenal, Pancreas, Liver, Spleen and Kidney
  5. Near Swadhishthan Chakra – Testicles and Ovary.


  • Pinel Gland: It is located in a small cave-like hole a little hole a little above the hind part of the pituitary gland in the middle of the brain.
  • It is instrumental in the growth of the body and controls the sex-glands.
  • It is related to the self-regulated nervous system of the body.
  • The secretion of this gland controls other glands.
  • It normalizes the effect of light on the color of the skin and balances the cells of the brain. It is also helpful in the prevention of general deformities.

Important Note

The following methods are very effective in activating this gland (1) Meditation (2) The first and twelfth posture of Surya Namaskar (3) Shashank asan and (4) Shirsh asan


  • Pituitary Gland: This gland is located at the base of the brain inside the skull and is connected with the hypothalamus. This gland functions with the help of other glands. This gland becomes active when other glands stop functioning. When the secretion of the glands of other hormones increases this gland reduces its secretion.
  • Decrease and increase in height depends on the secretion of this gland as it affects both our bones and muscles.
  • This gland activates the seminal cells in men and ovary in females.
  • Breasts of a mother get filled milk after the delivery of a child due to this very gland.
  • This gland influences the vessels in the kidneys and stimulates them to absorb more liquid. It reduces urination.

Note: One should practice meditation and asanas to stimulate this gland.

    • Thyroid Gland: This gland is located at the upper end of the bronchial tube near the vocal cord. This gland is heavier in women than in men. It grasps the fundamental substance called iodine.
    • This gland keeps our youth intact.
    • It utilizes iodine in the secretion of those hormones which are helpful in the metabolism of fats, proteins, and carbohydrates. Thus it helps in the process of digestion.
  • It is especially helpful in the production and distribution of electric energy in the brain.
  • The secretion of this gland helps in building up nerves and brain tissues.
  • It keeps up the equilibrium of the brain or intellectual harmony is sustained by this very gland.

Special Note

The fifth and eighth pose of Surya Namaskar, Bhujangasan, Sarvangasana and Matsyasan (First pose) are very effective in activating this gland.


  • Parathyroid Glands: These glands are located above and below the thyroid gland near the vocal cord. It is sheltered by the left and right portions of the thyroid gland. Both in their function and formation, they are entirely different from the thyroid gland. These glands control the quantum of calcium in the blood and play an important role in activating our muscles & nervous system.


Irregular secretion from these glands results in many diseases, such as the decay in bones, frailibility etc.


  • Thymus Gland: This gland is nestled behind the meeting point of collarbone and neck in the middle of the chest a little above the heart. It has got two chunks. It takes care of the body development of our babies and protects them from the disease. This gland does not allow the sex glands to grow up to this age.


It is instrumental in the proper development of the brain.

It also helps in the formation of our lymph cells.

It is instrumental in the process of the excretion of foreign matter from our body.

Special Note

This gland is activated by the sixth pose of Surya Namaskar Shalabhasan, Ushtrasan, and Ujai Pranayam.

  • Adrenal Gland: Two triangular glands above the kidneys and attached to the diaphragm are called Adrenal Gland. Like other glands, this gland discharges maximum quantum of secretion. The secretion of this gland is most essential for the protection of our life. Its cortisone-like hormones cures more than one hundred diseases like gout, defects of blood circulation, defects of the colon (large intestine), cancer and Asthma, etc.
  • It is helpful in the change of our emotions.
  • It is such an important gland that survival without it is impossible.
  • It increases metabolism.
  • It stimulates the liver to convert glycogen into glucose.
  • It helps in the contraction of different kinds of arteries in the skin and internal organs but at the same time, it expands our muscles and the arteries of the heart.
  • In a state of emergency or a sudden calamity, this gland creates a sense of alertness in the body and prepares us to face squarely a dangerous situation by inculcating in us a feeling of internal strength and security.

Special Note

In order to keep this gland in sound health the following Asanas and Pranayams are greatly helpful:

  1. The seventh pose of Surya Namaskar, Janushirasan, Paschimuttanasan Konasan, Ushtrasan, Bhujangasan, Shalabhasan, Dhanurasan, and Mayurasan.
  2. Agnisar Kriya, Surya Bhedi, Kapal Bhati and Bhastrika Parnayam.

Note: Please look up Liver, Pancreas, Kidneys, and Sex-glands in our discussion of the Digestive System.


Weighing 3 pounds, a walnut-shaped organ, made of white and grey tissues.
The brain is housed inside the skull. For a man, the brain is supposed to be the most important
organ. Memory, personality, reactions, receiving and transmissions of messages and
issuing of commands to the activities of the body – all these are controlled by the
brain. Forgetfulness and timely recollection is its greatest specialty.
Centers of the systems, such as the digestive system, the respiratory system,
the circulatory system, the glandular system, the excretory system and the nervous
a system is located in the brain.


The brain is divided mainly into three parts; the forebrain, the midbrain and
the hind brain. The fore brain is the largest part and most of its is composed of two
cerebral hemispheres. The right hemisphere is separated from the left by a deep
midline groove which contains the falx-cerebri.
Cerebellum: The left part of the brain controls the right side of the body and
the right side controls the left side. Our body controls several organs as pairs-such
with two adrenal glands, two kidneys, two lungs, two brain hemispheres etc. This part
of the brain helps us mainly in the regulation of speed harmony, movement of the
body and inhalation. In such activities, one does not need to concentrate.
Cerebrum: Cerebrum is composed of both the frontal cerebral hemisphere
and the right cerebral hemisphere. It controls such faculties as consciousness,
emotion, thoughts, and utterance of feelings and the control of our desires. If one part
of the cerebrum is affected, its impact is felt in all other parts accordingly, as its areas
are strongly connected with one another by neurons (nerve cells). If it does not
function properly, other parts are also adversely affected. Cerebrum also governs the
areas of organs of perception or knowledge (“Gyan Indriyas”) and our muscular
movements. The space between the cerebrum and the spine is known as Medulla
Oblongata. Messages are received and transmitted through cerebrum.
Any kind of injury or the formation of a clot is fatal for the brain. They
adversely affect the whole body. The above mentioned facts are quite consistent
with the medical science. But our sages “Rishis” and saints have made far deeper
research into the mechanism of the brain. The enquiry of the mind is far beyond that
of the brain. It is like this.
The mind transits thoughts to the intellect for its approval. After their approval
by the brain, it sends its commands to the sense organs accordingly and the sense
organs in their turn activate the different parts of the body for their compliance.
Let us now consider the functioning of the sense organs. When our eyes
observe and object they pass it on to the mind which in its turn takes orders from the
intellect which in its turn gives order to the feet to move on towards the destination.
Likewise the hands get order to touch an object to know its qualities. The sense of
tongue is ordered by the intellect to feel its quality by virtue of taste. The sense of
hearing, the ear is to understand the quality of an object by virtue of sound. This is
how the different sense organs are pressed into service for the attainment of a single

object. But with what coordination and quickness, the whole process takes place is
difficult to imagine. But after the attainment of the object, one not only experiences a
feeling of joy, but also an experience of contentment in one’s mind, because one
feels, completely satiated after the object is attained. It must be noted here that real
happiness does not lie in the attainment of an object. It lays the renunciation of its


Spine is the expansion of our brain. It is about 45 centimetres long. It consists
of 33 vertebrae, each part connected with the other by means of a joint. These joints
help the spinal cord to absorb shocks. The safety of the spine is ensured by armour
of three layers. Liquid substance keeps flowing through its midst. The spine is not
absolutely straight, but curved at 5 points. This enables us to move in all directions-
left and right, forward and backward.
The uppermost part of the neck………………….7 vertebrae (Cervical)
Below that in the thorax region…………………..12 vertebrae (Thoracic)
Below that in the lumbar region………………….5 vertebrae (Lumbar)
Below the waist in the anal region……2 vertebrae (Sacral and Coccygal) (5+4)
– These are connected with each other.
Thirty one (31) pairs of veins
emanate from these vertebrae. Around
half of these veins send messages to the
brain. The remaining ones transmit
messages from the brain to the muscles.
In moments of mental disturbances and
emotional crisis the muscles remain
extremely tense; otherwise in normal
conditions they remain quite healthy.

The following diagram will clarify the working efficiency of each vertebra of the
spinal cord in different parts of the body :
Certical C Vertebrae of the neck 7
Thoracic T Vertebrae of the year 12
Lumber L Vertebrae of the waist 5
Coccyx O Vertebrae of the Basti area
Coccygal 5 and 4 Combined 1 + 1 = 2 2 26


Vertebra : Physical Region of Spinal Nerves
C-1 Head, Pineal Gland, Skull, Brain, the Facial Bones, Inner section of the Ear,
Sympathetic Nervous system.
C-2 Optic Nerves, Nudotory Nerves, Feeding Nerves, Mastoid, Tongue and
C-3 Cheeks, the outer section of the Ear, Teeth and Trifacial Nerve
C-4 Nose, Lips, Mouth and Eustachian Nerve
C-5 Sound Nerves, Glands of the Neck and Pharyns
C-6 Muscles of the Neck, Shoulders and Tonsils
C-7 Thyroid Gland, Bursa in Shoulder, Arms


T-1 Hand-from the elbows to the fingers, Food pipe, Esophagus and Trachea
T-2 Heart, Heart valve, Coronary Canal
T-3 Bronchial tube, Pleura, the cover circling all the four sides of the Lungs,
Breasts and Chest
T-4 Gall Bladder, Common Duct
T-5 Liver, Solar, Plexus, Blood
T-6 Stomach
T-7 Pancreas…….and Deodenum
Secret of Human Body
T-8 Spleen & Diaphragm
T-9 Adrenal Glands
T-10 Kidneys
T-11 Ureters, Kidneys
T-12 Fallopian Tube & Lymph Circulion


L-1 Large Intestine and Inguins Rings
L-2 Appendix, Abdomen
L-3 Male Organ, Dimba Gland, Uterus, Knees and Bladder
L-4 Prostate Glands, Muscles under the lower part of the Waist
L-5 The under part of the Knees, Ankles, Pawn, The mid-circle under the Feet,
Sciatica Nerve
Sacrum – Buttocks and its bones
Rectum – Kidney and Anus


During the practice of Yoga, we give sometimes a forward movement or a
back movement to the spine & sometimes the movement is given by inhaling and
sometimes by exhaling the breath.
In some Asans (postures) we bend it towards the right and left, while in some
other asans we bend the spine below the middle towards right and above the middle
towards left. In some asans we try to stretch it towards the earth. Sometimes we
keep it parallel to the earth or sometimes in a horizontal way. The different postures

have a salutary effect on the vertebrae of the spine, its mid-joints and the root-
nerves. As a result of it the cerebral column remains strong and elastic.
Not only this, the distribution centres of five Prans, situated on the spinal cord
are deeply influenced by it. Its impact is also felt on the entire body-from the head of
the foot, bones, muscles, blood circulation, nerve-system as well as other systems of
the body. Besides our respiratory system too gets completely overhauled.
All that we have said above is concerned with the physical form of the spine.
But there are such centres and veins in the body that are purely subtle or astral.
They are not visible to the naked eye like veins or arteries. The power of our vital
energy i.e. Pran reaches the different parts of the body through these subtle veins.
Each Chakra stands at each of the five bends of the spine, where also is situated the
confluence of the veins. One can have a clear understanding of these bends of the
spine in the spine diagram given on page 5.
These Chakras (Spiritual Centres) are close to those gross centres that
doctors are familiar with. These subtle centres affect the subtle veins, the subtle
veins the gross centres and the gross centres in turn affect the veins and arteries.
We have explained them in detail in the chapter on Pranayam. By controlling the
body we can control these spiritual centres through there are innumerable such
veins in our body, the number of the main Nadis are there – (1) Ida. (2) Pingla and
(3) Sushumna. They keep the body cool, warm and balanced respectively.
Yoga has the capacity to purify all these Nadis and influence the Sushumana
Nadi that passes through the middle of the spinal cord. It also awakens its dormant


Here we find it necessary to make you familiar with a general knowledge of
the mind. Pran stands between the gross body and the Mind & makes its impact on
both. The difference between the Brain and the Mind is this that while the former is
gross, the Mind is subtle or astral. The brain can be cut opened and operated upon, but
not the Mind. The region where thoughts come and go, where resolutions rise and
fall is called the Mind.
One of the functions of the mind is to help flow the experienced sensations
into the different parts of the body through the agency of the nadis. The brain lies
asleep, but the mind knows no peace. In Yoga, the mind is supposed to have three parts-
Conscious, subconscious and unconscious. We make use of only a little energy
generated by them. The major part of the energy of the mind remains unused. It is
only the practitioners of Yoga that can benefit from the unlimited potentiality of the
mind. It is so subtle in nature that it is impossible to measure its length and breadth.
It is made up of extremely subtle waves or threads. In moments of anger it assumes
the form of formidable hatred. IN hours of greed it is saturated with passion and
attachment. The mind can observe anything not visible to the naked eye. Mind is also the
creator of the dream world.
Mind also gives rise to different feelings-sharpness valour, peace,
deceptiveness etc. It has the capacity to swallow any form or shape, no matter
howsoever big or small it may be. Mind is the only substance that haunters round the

interior and the exterior of the body. Desire, thought and action are three corollaries
of the Mind. In its very nature it is liable to change any time and every time. In dream
it creates its own world, in sushapti (deep sleep) it ceases to exist.

Dazzled by the fascination of the materialistic life the modern man is busy only in the
discovery of the external objects of the world. But has perhaps no time or curiosity to
understand the structure of his own body. Is it not an irony of ironies that we are
completely ignorant of the structure of the body through the medium of which one
carries out all the activities of life, understands all things of life and carries on the
various researches. It is, therefore, necessary to know about its important organs. A
general knowledge of these organs will prove very useful for the practice of Yoga.
There are three parts of the body :
(1) The Physical Body
(2) The Astral Body
(3) The Causal Body
Discussion of the Astral and the Causal bodies will be found in the chapter on
“Pranayam”. Here we shall try to describe the structure of the Physical Body for
the benefit of the common man who should be familiar with the general
knowledge of the main organs of the human body.


Cells are those small units of the living organism that form the fundamental
basis in the making of the humans and other beings. They are not visible to the
naked eye, therefore, can be observed only by the microscope. In spite of being
different from one another they possess certain similarities, One will be surprised to
know that their number has been estimated to be 6000 billion. Cells perform different
functions. For example, tissue cells expand and contract. They are also present
under the layers of the skin. The brain cells are helpful in the thinking process. Eye
cells transmit rays to the brain. The beatings of the heart lead to the expansion of
the heart through the process of breathing. It is all the work of the cells. Not only this
they also provide energy in the blinking of the eyes, raising of the hands and such
other movements of the body organs. How many cells are built in a minute and
destroyed in the functioning of the body is difficult to speculate? In itself, it is altogether a
different world. In spite of their huge number, they work in complete union with one-
Functions: Primarily, the cells perform some important functions. Their main
function is to provide the raw material, convert it into the natural product and then
to work on the unused portion. The mainstream of life is so inextricably connected
with them that life continuous so long as the dead cells are replaced by the new


Different kinds of cells :

  1. Mitochondrion
  2. Ribosome
  3. Nucleus
  4. Vacuole
  5. Cytoplasm


A group of Cells is known as tissue which only performs one type of specific


When tissues perform collectively different functions of some particular part of
the body, which can be identified from other parts by its shape and qualities, that
particular part is called an organ, e.g. brain, liver, stomach etc.

Understanding a SYSTEM

When a group of many organs work together for a particular kind of function, it
is known as a System. There are nine such systems in our body.
As a result of the different Yoga practices, there is a lesser possibility of the
destruction of elimination of cells and a greater possibility of their formation. This is a
very important secret of the maintenance of one’s health and prolongation of youthful
The main systems to understand are