Shri Bhagawan uvācha, “O King! I will tell you the nature of the human body. Listen carefully. The universe is indeed born from Me. It is sustained by Me only. It merges in Me alone who is its foundation just as silver appears to be in a shell.
But I am Brahman, blemishless, infinite, of the very form of Existence, Consciousness and Bliss, unattached, egoless, pure and timeless.
I assume the creation of the world through the association with ignorance which is beginningless.
This stupendous ignorance is indeterminable, well known to consist of three qualities namely sattva, rajas and tamas and the dynamic matrix of the world.
The sattva quality of maya is said to be white and pure and is the basis of knowledge and pleasure for people. Rajas is said to be red in colour, of the nature of activity and is the basis of pain.
Tamas is said to be black in colour, inert and sluggish and prone to pleasure.
Therefore, the power of maya with its three qualities evolves into the form of the world only by virtue of being connected with Me as its ground, just as the illusory silver is grounded in the real shell or the illusory snake is grounded in the real rope.
The five elements (pancha bhutas) have emerged from Me. This entire universe is constituted by them. And the human body is a product of the five elements.
From the food taken by the father, the foetus in the womb develops the six sheaths. Thus, tendons, bones and marrow come from the father.
And from the mother is born the skin, flesh and blood. Thus, the constituents of the body are six-fold derived from the mother and father. In the same way, the seven factors are born of one’s own self. They are due to one’s own past deeds and one’s own bodily essence.
The elements of the blood, fat, marrow, spleen, liver, anus, heart and navel are said to be produced from the mother.
The hair on the face, in the head, other parts of the body, locks of hair, marrow of the flesh, subtle and gross veins, nails, teeth and semen are produced from the father.
The development of the body at birth, complexion, growth, satisfaction, strength, firmness, absence of helplessness and enthusiasm are known to be products of the essences of the body.
Likes and dislikes, pleasure and pain and right and wrong which decide the future of a person and effort, knowledge, lifespan and the sensory organs are all the results of one’s own past actions and inactions.
The sensory organs of knowledge are ears, skin, eyes, tongue and nostrils and their attributes and functions are five.
The wise people say that the five sensory attributes are sound, touch, form, taste and smell and the five organs of action are speech, hands, feet, organ of evacuation and organ of procreation.
Know that speech, grasping, going, evacuation and sexual pleasures are the functions of the organs of action. The function of the mind is both of a sensory organ and an organ of action.
The internal organ is four-fold according to the different functions of mind, intellect, egoity and memory power.
Reflection on things as this or that, fear and others are the functions of the mind. And pleasure and pain are also states of the mind. Intellect has the function of analysing things. The egoity is the notion of I and mine. The memory and recall are the functions of chitta. Hence, the different types of sadhana have been spoken of to achieve antahkarana tyāga, antahkarana sannyāsa and chitta suddhi.
The internal organ which is called sattva is three-fold according to the difference in the qualities of sattva, rajas and tamas. Pure thoughts arise from sattva.
From sattva that renders faith in the scriptures, blemishless purity, steadfast devotion to righteousness and rightful duty and others descend on one. From rajas, passionate lust, animosity, conceit and others appear.
Sleep, sloth, inattention, laziness, deceit and others are the qualities of tamas while sense organs with clarity, health, absence of sloth and others are produced from sattva.
The body is identified with the Self that is the knower. That is why it has these qualities like the ears to hear the sound, ability to speak, power to do actions and inactions and think with ease and clarity.
Along with the aforementioned six qualities, strength is derived from space.
And similarly, expansion, hardness and the vital airs of prāna, apāna, vyāna, samāna and udāna and other variations of nāga, kūrma, krkala, devadatta and dhananjaya make it nineteen qualities of air.
Of these, prāna is the most important and is established between the navel and throat. It moves in the region of the navel, heart lotus and nostrils.
This prāna is also the cause of sound, speech, inhalation and exhalation.
The apāna is stationed in the anus, penis, hip, stomach, navel, throat, thighs, knees and the legs below the knees. Its function is known to be the evacuation of urine and faeces.
The air vyāna is established in the eyes, ears, ankles, tongue and nostrils. Its action is breath control, maintaining the breath, exhalation and inhalation.
The air called samāna pervading the entire body along with fire and moving about 72,000 nādis strengthens the body by properly distributing the essences of what is eaten and drunk.
Udāna is established in the feet, hands and the joints of the limbs.
The principal function of udāna is to raise the body. The five supplementary airs are found in the sensory organs.
The functions of the supplementary airs are hiccups, vomiting and others. Of kūrma, are closing and opening of eyes and others, of krkala, hunger and thirst, of devadatta, sleep and others and of dhanajaya, grief, pleasure and others.
Of fire, the functions are sight, form, white radiance, cooking, fighting, anger, inability to undergo misfortune, subtlety, the heat, scorching sun and might.
From water comes power of retention, taste, coolness, viscidity, liquid, sweat and softness of body.
From earth are taken the sense of smell, stability, steadfastness, heaviness and the bodily constituents of skin, blood, flesh, fat, bone, marrow and semen.
The food eaten by humans and others digested by the jatara agni becomes threefold. The grossest part becomes faeces. The medium becomes flesh and the subtle becomes the mind. Therefore, the mind is constituted by the food partaken.
The grossest part of water becomes urine, medium becomes blood and the subtle part turns to vital air. Hence, it has been said that vital air is of the nature of water.
From the grossest part of the fire element, bones are produced, from the medium part, marrow and from the subtle part, speech. That is why this world is of the nature of fire, water and earth.
From blood is born flesh, from flesh, fat is produced, from fat, bones are made and from bones, marrow is produced.
The nādis are born of flesh. The semen is born of marrow.
Here, air, bile and phlegm are known as the elemental dhātus. Water is of ten measures of magnitude, taste of nine.
Eight measures for blood, seven for faeces, six for phlegm, twenty for bile and three for urine.
Two measures for marrow of flesh, two for fat, one for marrow of the bone, half for semen and that alone is called strength.
There are 360 bones in the body with five classes namely jalaja, kapāla, ruchāka, astarana and nalaka.
The joints of the bones are 210. These are called rauravas, prasaras, secanas, ulūkalas, samudgas, mandalas, sankhāvartas and vāmanakundalas are eight bone joints in the bodies.
There are 35 million hair on the body, 3 lakh hair on the beard. O son of Dasaratha! The constitution of the body has been described well. Hence, in all the three worlds there is nothing more than this body that is without essence.
The tragedy is that people do not think of the way to liberation due to attachment to this body and sin of egoity.
Therefore, the true nature of this body has to be learnt by wise people.”
[Siva Gita – Chapter 9 – The description of the body – Slokas 1 – Slokas 51, Uttara Khanda, Padma Purana]