Down the Gullet. When the food has been thoroughly moistened and crushed in the mouth and rolled into a
lump, or bolus, at the back of the tongue, it is started down the elevator shaft which we call the gullet, or
esophagus. It does not fall of its own weight, like coal down a chute, but each separate swallow is carried
down the whole nine inches of the gullet by a wave of muscular action. So powerful and closely applied is this
muscular pressure that jugglers can train themselves, with practice, to swallow standing on their heads and
even to drink a glass of water in that position; while a horse or a cow always drinks "up-hill." This driving
power of the food tube extends throughout its entire length; it is carried out by a series of circular rings of
muscles, which are bound together by other threads of muscle running lengthwise, together forming the
so-called muscular coat of the tube. By contracting, or squeezing down in rapid succession, one after another,
they move the food along through the tube. The failure of these little muscles to act properly is one of the
causes of constipation and biliousness. Sometimes the action of the muscles is reversed, and then we get a
gush of acid, or bitter, half-digested food up into the mouth, which we call "heart-burn" or "water-brash."
The Stomach--its Shape, Position, and Size. By means of muscular contraction, then, the gullet-elevator
carries the food into the stomach. This is a comparatively simple affair, merely a ballooning out, or swelling,
of the food tube, like the bulb of a syringe, making a pouch, where the food can be stored between meals, and
where it can undergo a certain kind of melting or dissolving. This pouch is about the shape of a pear, with its
larger end upward and pointing to the left, and its smaller end tapering down into the intestine, or bowel, on
the right, just under the liver. The middle part of the stomach lies almost directly under what we call the "pit
of the stomach," though far the larger part of it lies above and to the left of this point, going right up under the
ribs until it almost touches the heart, the diaphragm only coming between.[3] This is one of the reasons why,
when we have an attack of indigestion, and the stomach is distended with gas, we are quite likely to have
palpitation and shortness of breath as well, because the gas-swollen left end of the stomach is pressing upward
against the diaphragm and thus upon the heart and the lungs. Most cases of imagined heart trouble are really
due to indigestion.
The Lining Surface of the Stomach. Now let us look mo