Physiology and Hygiene for Secondary Schools

by Francis M. Walters

The following table shows the main elements in the body and their relation to the different nutrients:

The recently advanced theory that the molecules of the mineral salts, by dissolving in water, separate into smaller divisions, part of which are charged with positive electricity and part with negative electricity, has suggested several possible uses for sodium chloride and other mineral salts in the body. The sodium chloride in the tissues is in such concentration as to be practically all separated into its sodium and chlorine particles, or ions. It has recently been shown that the sodium ions are necessary for the contraction of the muscles, including the muscles of the heart. There is also reason for believing that the different ions may enter into temporary combination with food particles, and in this way assist in the processes of nutrition.

Chittenden, The Nutrition of Man.

Compiled from different sources, but mainly from Atwater's Foods: Nutritive Value and Cost, published by the U.S. Department of Agriculture.

The calorie is the adopted heat unit. As used in this table it may be defined as the quantity of heat required to raise 1 kilogram (2.2 pounds) of water, 1 degree centigrade. The calories also show the relative amount of energy supplied by the different foods.

While alcohol cannot be classed as a food, it is believed by some authorities to contain food value and, in the hands of the physician, to be a substance capable of rendering an actual service in the treatment of certain diseases. It might, for example, be used where one's power of digestion is greatly impaired, since alcohol requires no digestion. But upon this point there is a decided difference of opinion. Certain it is that no one should attempt to use alcohol as food or medicine except under the advice and direction of his physician.

A layer of connective tissue between the mucous membrane and the muscular coat is usually referred to as the submucous coat. This contains numerous blood vessels and nerves and binds the muscular coat to the mucous membrane.

The saliva may continue to act for a considerable time after the food enters the stomach. "Careful examination of the contents of the fundus (large end of the stomach) by Cannon and Day has shown that no inconsiderable amount of salivary digestion occurs in the stomach."—FISCHER, The Physiology of Alimentation.

Perhaps the simplest method of inducing vomiting is that of thrusting a finger down the throat. To make this method effective the finger should be held in the throat until the vomiting begins. An emetic, such as a glass of lukewarm salt water containing a teaspoonful of mustard, should also be taken, and, in the case of having swallowed poison, the vomiting should be repeated several times. It may even be advantageous to drink water and then vomit it up in order to wash out the stomach.