DIGESTION

Hatha Yoga – Chapter 5: The Laboratory of the Body

By William Walker Atkinson

This little book is not intended for a text-book upon physiology, but inasmuch as the majority of people seem to have little or no idea of the nature, functions and uses of the various bodily organs, we think it as well to say a few words regarding the very important organs of the body which have to do with the digestion and assimilation of the food which nourishes the body—which perform the laboratory work of the system.

The first bit of the human machinery of digestion to be considered by us are the teeth. Nature has provided us with teeth to bite our food and grind it into fine bits, thus rendering it of a convenient size and consistency to be easily acted upon by the saliva and the digestive juices of the stomach, after which it is reduced to a liquid form that its nourishing qualities may be easily assimilated and absorbed by the body. This seems to be merely a repetition of an oft-told tale, but how many of our readers really act as if they knew for what purpose their teeth had been given them? They bolt their food just as if teeth were merely for show, and generally act as if Nature had provided them with a gizzard, by the aid of which they could like the fowl grind up and break into small bits the food that they had bolted. Remember friends that your teeth were given you for a purpose, and also consider the fact that if Nature had intended you to bolt your food she would have provided you with a gizzard instead of with teeth. We will have much to say about the proper use of the teeth, as we go along, as it has a very close connection with a vital principle of Hatha Yoga, as you will see after a while.

The next organs to be considered are the Salivary Glands. These glands are six in number, of which four are located under the tongue and jaw, and two in the cheeks in the front of the ears, one on each side. Their best known function is to manufacture, generate or secrete saliva, which, when needed, flows out through numerous ducts in different parts of the mouth, and mixes with the food which is being chewed or masticated. The food being chewed into small particles, the saliva is able to more thoroughly reach all portions of it with a correspondingly increased effect. The saliva moistens the food, thus allowing it to be more easily swallowed, this function, however, being a mere incident to its more important ones. Its best known function (and the one which Western science teaches is its most important one) is its chemical offices, which convert the starchy food matter into sugar, thus performing the first step in the process of digestion.

Here is another oft-told tale. You all know about the saliva, but how many of you eat in a manner which allows Nature to put the saliva to work as she had designed? You bolt your food after a few perfunctory chews and defeat Nature’s plans, toward which she has gone to so much trouble, and to perform which she has built such beautiful and delicate machinery. But Nature manages to “get back” at you for your contempt and disregard of her plans—Nature has a good memory and always makes you pay your debts.

We must not forget to mention the tongue—that faithful friend who is so often made to perform the ignoble task of assisting in the utterance of angry words, retailing of gossip, lying, nagging, swearing, and last but not least, complaining.

The tongue has a most important work to perform in the process of nourishing the body with food. Besides a number of mechanical movements which it performs in eating, in which it helps to move the food along and its similar service in the act of swallowing, it is the organ of taste and passes critical judgment upon the food which asks admittance to the stomach.

You have neglected the normal uses of the teeth, the salivary glands and the tongue, and they have consequently failed to give you the best service. If you but trust them and return to sane and normal methods of eating you will find them gladly and cheerfully responding to your trust and will once more give you their full share of service. They are good friends and servants, but need a little confidence, trust and responsibility to bring out their best points.

After the food has been chewed or masticated and then saturated with saliva it passes down the throat into the stomach. The lower part of the throat, which is called the gullet, performs a peculiar muscular contraction, which pushes downward the particles of food, which act forms a part of the process of “swallowing.” The process of converting the starchy portion of the food into sugar, or glucose, which is begun by the saliva in the mouth, is continued as the food passes into and down the gullet, but nearly, or entirely ceases, when the food once reaches the stomach, which fact must be considered when one studies the subject of the advantage of a deliberate habit of eating, as, if the food is hastily chewed and swallowed, it reaches the stomach only partially affected by the saliva and in an imperfect condition for Nature’s subsequent work.

The stomach itself is a pear-shaped bag with a capacity of about one quart or more in some cases. The food enters the stomach from the gullet on the upper left-hand side, just below the heart. The food afterwards leaves the stomach on the lower right-hand and enters the small intestine by means of a peculiar sort of valve, which is so wonderfully constructed that it allows the matter from the stomach to pass easily through it, but refuses to allow anything to work back from the intestine into the stomach. This valve is known as the “Pyloric Valve” or the “Pyloric Orifice,” the word “Pyloric” being derived from the Greek word which means “gatekeeper”—and indeed this little valve acts as a most intelligent gatekeeper, always on the watch, never asleep.

The stomach is a great chemical laboratory in which the food undergoes chemical changes which allow it to be taken up by the system and changed into a nourishing material which is converted into rich, red blood which courses all over the body, building up, repairing, strengthening and adding to all the parts and organs.

The “inside” of the stomach is covered with a lining of delicate mucous membrane, which is filled with minute glands, all of which open into the stomach and around which is a very fine network of minute blood-vessels with remarkably thin walls, from which is manufactured, or secreted, tha