Mouth, Pharynx And Esophagus
( Originally Published 1938 )
When you convey a piece of food to your mouth, particularly if it is savory, you instinctively roll it about, with your tongue and crunch or chew it with your teeth in order to get its full flavor and to swallow it with ease. Flavor, we have learned, is important for good digestion for it helps to increase the flow of digestive juices, just as the sight and smell of appetizing food do. By rolling the food about the mouth and chewing it, it is broken up into small particles with the aid of saliva and therefore reaches all the taste buds on the tongue so that you can delight in the delicious flavor of the morsel while at the same time the digestive juices are getting ready for their work.
Mastication has another function which many authorities consider more important than the two we have just cited: it directly aids digestion in two ways first, by breaking the food into smaller bits, it enables the various digestive fluids to do their work with greater ease since broken up they can penetrate the food more readily and, secondly, by mixing the food with saliva which is the first digestive fluid with which the food comes in contact. The saliva contains a digestive ferment or enzyme, ptyalin, which acts on starches, breaking them down into simple sugars.
To just what degree of fineness food should be masticated is a debatable question. A few decades ago thorough mastication to the point where the food and saliva formed a consistency of thin cream was all the rage. If you didn't "Fletcherize", as this type of chewing was called after its prime advocator, you were doomed to an early death, and even worse, might become a social outcast. However, Fletcher himself died rather prematurely in spite of his chewing and "Fletcherism" lost its prestige. But on the other hand, we have all experienced, at some time or other, the disagreeable effects of "bolting" our food and as we have described them in a previous chapter, there is no need to dwell upon them here. The best thing to do is to strike a happy medium between Fletcherism and bolting. In this way indigestion and consequent constipation due to bolting may be avoided as well as the boredom of Fletcherism which is only partly relieved by watching the faces of your table companions go through rabbit-like contortions!
After the food is swallowed it passes into the pharynx or throat and from there into the esophagus, a tube continuous with the pharynx, about eight inches long in a grown person. Wavelike contractions of this tube propel the food to the stomach where it enters the cardiac orifice of the stomach. This part of the stomach is so named by reason of the fact that it is located near the heart, that is, slightly on the left side of the body, just below and back of the lower ribs.