V. The Laboratory of the Body
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 bad 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 make 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 bloodvessels
with remarkably thin walls, from which is manufactured, or secreted, that wonderful fluid, the gastric juice.
The gastric juice is a powerful liquid acting as
a solvent upon what is called the nitrogenous portions
of the food. It also acts upon the sugar or glucose which
has been manufactured from the starchy food by the
saliva, as above described. It is a bitter sort of liquid, containing a
chemical product called pepsin, which is its active agent and which plays a
most important part in the digestion of the food.
In a normal, healthy person the stomach manufactures
or secretes about one gallon of gastric juice in twenty-four hours, and uses same in the process of digestion of the food. When the food reaches the stomach the little
glands, before mentioned, pour out a sufficient supply
of the gastric juice, which mixes up with the mass of
food in the stomach. Then the stomach sets up sort
of a churning motion, which moves the pulpy food round and round, from end to
end, from side to side, twisting and turning it,
churning and kneading it, until the gastric juice penetrates every part of the
mass and is well mixed up into it. The Instinctive
Mind does some wonderful work in the stomach
movements and works like a well oiled machine.
And
if the stomach has been treated to properly prepared,
well chewed food, properly insalivated, the machine is
able to turn out a fine job. But if, as so often happens, the food is of a quality not fit for the human stomach-or
if it has been but half chewed, or bolted- or if the
stomach has been "stuffed" by a gluttonous owner-there
is going to be trouble. In such a case, instead
of the normal process of digestion being performed,
the stomach is unable to do its work and fermentation results, and the stomach becomes
the holder of a fermenting, putrefying, rotting mass-an
"yeast pot" it has been called under such
circumstances. If people could but form an idea of
what a cesspool they maintain in their stomachs they would cease to
shrug their shoulders and look bored whenever the subject of rational and sane
habits of eating are mentioned.
This putrefying ferment, arising
from abnormal habits of eating, often becomes chronic and results in a
condition which manifests itself in the symptoms of what is called
"dyspepsia," or similar troubles. It re mains in the stomach for a
long time after the meal, and then when the
next meal reaches the stomach the fermentation continues until the stomach
actually becomes a perpetually active "yeast pot." This
condition, of course, results in an
impairment of the normal functioning of the stomach, the surface of
which becomes slimy, soft, thin and weak. The glands become clogged and the
whole digestive apparatus of the stomach
becomes impaired and broken down. In such event the half digested food
passes out into the small intestine,
tainted with the acids arising from fermentation, and the result is that the
whole system becomes gradually poisoned and imperfectly nourished.
The food-mass,
saturated with the gastric juice which has been poured upon it
and kneaded and churned into it, leaves the stomach by the Pyloric orifice on
the lower right-hand
side of the stomach and enters the small intestine.
The small intestine is a tube-like
canal ingeniously coiled upon itself so as to occupy but a comparatively small
space, but which is really from twenty to thirty feet in length. Its inner
walls arc lined with a velvety substance, and through the greater part of its
length this velvety lining is arranged in transverse shelf-like folds, which maintain a sort of
"winking" motion, swaying backward and forward in the
intestinal fluids, retarding the passage of the food and providing
an in* creased surface for secretion and
absorption. The velvety condition of this mucous lining is caused by numerous minute elevations, something like the
surface of a piece of plush, which
are known as the intestinal "villi,"
the office of which will be explained a little further on.
As soon as the food-mass enters the
small intestine it is met with a peculiar
fluid called the bile, which saturates it and is thoroughly mixed up
with it The bile is a secretion of the liver and is stored up ready for use in
a strong bag, known as the gall bladder. About
two quarts of bile per day is used in saturating the food as it passes
into the small intestine. Its purpose is to assist the pancreatic juice in
preparing the fatty parts of the food for
absorption and also to aid in the prevention of decomposition and
putrefaction of the food as it passes through the small intestine and the neutralization of the gastric juice which has
already performed its work. The pancreatic juice is secreted by the pancreas, an elongated organ situated just
behind the stomach, and its purpose
is to act upon the fatty portions of the food and to render them possible of absorption
from the intestines along with the other parts
of the food nourishment. About one and one-half pints is used daily in
this work.
The hundreds of thousands of
plush-like "hairs" upon the velvety lining of the small intestine
(above alluded to), and which are known as "villi," maintain a
constant waving motion, passing through and in the soft, semi-liquid food which is passing through the small intestine. They are constantly in motion, licking up and absorbing the nourishment that is contained
in the food-mass and transmitting it to the system.
The several steps whereby the food is converted into blood and is carried to all parts of the system are as follows: Mastication, insalivation, deglutition, stomach and
intestinal digestion, absorption, circulation and assimilation. Let us run over
them again hastily that we may not forget them.
Mastication is performed by the teeth-it is the chewing
process-the lips, tongue and cheeks assisting in the
work. It breaks up the food into small particles and
enables the saliva to reach it more thoroughly.
Insalivation
is the process of saturating the masticated
food with the saliva which pours into it from the salivary
glands. The saliva acts upon the cooked starch in the
food, changing it into dextrine and then into glucose, thus rendering it
soluable. This chemical change is rendered
possible by the action of the pytaline in
the saliva acting as a ferment and changing the chemical constitution of those substances for which it has an
affinity.
Digestion is performed in the stomach and small intestines and
consists in the conversion of the food-mass
into products capable of being absorbed and assimilated. Digestion begins when the food reaches the
stomach. The gastric juice then pours out copiously, and, becoming mixed
up with and churned into the food mass, it
dissolves the connective tissue of meat, releases fat from its envelopes
by breaking them up and transforms some of
the albuminous material, such as
lean meat, the gluten of wheat and white of eggs, into albuminose, in which
form they are capable of being absorbed and assimilated. The transformation occasioned by stomach
digestion is accomplished by the chemical action of an organic ingredient of the
gastric juice, called pepsin, in connection with the acid ingredients of the
gastric juice.
While the process of digestion is
being performed by the stomach the fluid
portion of the food-mass, both that which has entered the stomach as
fluids which have been drunken, as well as
the fluids liberated from the solid food in the process of digestion, is
rapidly taken up by the absorbents of the stomach and is carried to the blood,
while the more solid portions of the food-mass
are churned up by the muscular action of the stomach, as we have stated.
In about a half-hour the solid portions of
the food-mass begin slowly to leave the stomach in the form of a grayish, pasty substance, called chyme,
which is a mixture of some of the sugar and salts of the food, of transformed
starch or glucose, of softened starch, of broken fat and connective tissue, and
of albuminose.
The Chyme, leaving the stomach,
enters the small intestine, as we have described and comes in contact with the
pancreatic and intestinal juices and with the bile, and intestinal digestion
ensues. These fluids dissolve most of the food that has not already been softened.
Intestinal digestion resolves the chyme into three substances, known as (1)
Peptone, from the digestion of albuminous particles; (2) Chyle, from the
emulsion of the fats; (3) Glucose, from the transformation of the starchy
elements of the food. These substances are,
to a large extent, carried into the blood and become a part of it, while
the undigested food passes out of the small intestine through a trap-door-like
valve into the large bowel called the colon, of which we shall speak bye-and-bye.
Absorption,
by which name is known the process by which the above-named
products of the food, resulting from the digestive process, are taken up by the veins and lacteals, is effected by endosmosis. The
water and the fluids liberated from the food-mass by the stomach digestion are rapidly absorbed and carried away by
the blood in the portal vein to the liver. The peptone and glucose from
the small intestines also reaches the portal vein to the liver through the
blood vessels of the intestinal villi, which
we have described. This blood reaches
the heart after passing through the liver, where it undergoes a process
which we will speak of when we reach the subject of the liver. The chyle, which
is the remaining product of the food-mass in
the intestines after the peptone and
glucose have been taken up and carried
to the liver, is taken up and passes through the lacteals into the
thoracic duct, and is gradually conveyed
to the blood, as will be further described in our chapter on the
Circulation. In our chapter on the circulation
we will explain how the blood carries the nutriment derived from the
digested food to all parts of the body,
giving to each tissue, cell, organ and part the material by which it
builds up and repairs itself, thus enabling the body to grow and develop.
The liver secretes
the bile, which is carried to the small intestine, as we have stated. It also
stores up a substance called glycogen,
which is formed in the liver from the
digested materials brought to it by the portal vein (as above
explained). Glycogen is stored up in the liver, and is afterwards gradually
transformed, in the intervals of digestion, into glucose or a substance similar to grape sugar. The pancreas secretes
the pancreatic juices, which it pours into the small
intestine, to aid in intestinal digestion, where it acts chiefly
upon the
fatty portions of the food. The kidneys are located in the loins, behind the intestines. They are two in number and are shaped like beans. They purify
the blood by removing from it a
poisonous substance called urea and
other waste products. The fluid secreted by " the kidneys is carried by two
tubes, called ureters, to the
bladder. The bladder is located in the pelvis and serves as a reservoir for the
urine, which consists of waste fluids carrying with it refuse matter of the system.
Before leaving this
part of the subject we wish to call the attention of our readers to the fact
that when the food enters the stomach and small intestines improperly masticated and insalivated-when the teeth and salivary glands have
not been given a chance to do their work
properly-digestion is interfered with and impeded and the digestive organs are overworked and are rendered
unable to accomplish what is asked of them. It is like asking one set of workmen to do
their own work in addition to the work which should have been previously performed by another set of
men-it is asking the railroad engineer to perform the duties of firemen as well as his own-to keep the fire going
on an up grade and run the
locomotive on a dangerous bit of road
at the same time. The absorbents of the
stomach and intestines must absorb something-that
is their business-and if you do not
give them the proper materials they
will absorb the fermenting and putrefying mass in the stomach
and pass it along to the blood. The blood
carries this poor material to all parts of the body, including the
brain, and it is no wonder that people
complain of biliousness, headache, etc., when they are being
self-poisoned in this way.
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