General View of the Body : Part 2

Physiology and Hygiene for Secondary Schools
by Francis M. Walters

(Page 3 of 24)

The various organs also combine with one another in carrying on the work of the body. An illustration of this is seen in the digestion of the food - a process which requires the combined action of the mouth, stomach, liver, intestines, and other organs. A number of organs working together for the same purpose form a system. The chief systems of the body are the digestive system, the circulatory system, the respiratory system, the muscular system, and the nervous system.

The Organ and its Work. - A most interesting question relating to the work of the organ is this: Does the organ work for its own benefit or for the benefit of the body as a whole? Does the hand, for example, grasp for itself or in order that the entire body may come into possession? Only slight study is sufficient to reveal the fact that each organ performs a work which benefits the body as a whole. In other words, just as the organ itself is a part of the body, the work which it does is a part of the necessary work which the body has to do.

But in working for the general good, or for the body as a whole, each organ becomes a sharer in the benefits of the work done by every other organ. While the hand receives only a little of the nourishment contained in the food which it places in the mouth or of the heat from, fuel which it places on the fire, it is aided and supported by the work of all the other organs of the body - eyes, feet, brain, heart, etc. The hand does not and cannot work independently of the other organs. It is one of the partners in a very close combination where, by doing a particulary work, it, shares in the profits of all. What is true of the hand is true of every other organ of the body.

An Organization. - The relations which the different organs sustain to each other and to the body as a whole suggest the possibility of classifying the body as an organization. This term is broadly applied to a variety of combinations. An organization is properly defined as any group of individuals which, in working together for a common purpose, practices the division of labor. This definition will be better understood by considering a few familiar examples.

A baseball team is an organization. The team is made up of individual players. These work together for the common purpose of winning games. They practice the division of labor in that the different players do different things - one catching, another pitching, and so on. A manufacturing establishment which employs several workmen may also be an organization. The article manufactured provides the common purpose toward which all strive; and, in the assignment of different kinds of work to the individual workmen, the principle of division of labor is carried out. For the same reason a school, a railway system, an army, and a political party are organizations.

An organization of a lower order of individuals than these human organizations is to be found in a hive of bees. This is made up of the individual bees, and these, in carrying on the general work of the hive, are known to practice the division of labor.

Is the Body an Organization? - If the body is an organization, it must fulfill the conditions of the definition. It must be made up of separate or individual parts. These must work together for the same general purpose, and, in the accomplishment of this purpose, must practice the division of labor. That the body practices the division of labor is seen in the related work of the different organs. That it is made up of minute, but individual, parts will be shown in the chapter following. That it carries on a general work which is accomplished through the combined action of its individual parts is revealed through an extended study of its various activities. The body is an organization. Moreover, it is one of the most complex and, at the same time, most perfect of the organizations of which we have knowledge.

Summary. - Viewed from the outside, the body is seen to be made up of divisions which are more or less familiar. Viewed internally, it is found to consist of different kinds of materials, called tissues. The tissues are adapted, by their properties, to different purposes both in the construction of the body and in carrying on its work. The working parts of the body are called organs and these in their work combine to form systems. The entire body, on account of the method of its construction and the character of its work, may be classed as an organization.

Exercises. - 1. Name and locate the chief external divisions of the body.

2. What tissues may be found by dissecting the leg of a chicken?

3. Name the most important properties and the most important uses of muscular tissue, osseous tissue, and connective tissue.

4. Define an organ. Define a system. Name examples of each.

5. Name the chief cavities of the body and the organs which they contain.

6. What tissues are present in the hand? How does each of these aid in the work of the hand?

7. Define an organization. Show that a railway system, an army, and a school are organizations.

8. What is meant by the phrase "division of labor"? In what manner is the division of labor practiced in a shoe or watch factory? What are the advantages?

9. What are the proofs that the body is an organization?

Practical Work

Observation on the Tissues. - Examine with care the structures in the entire leg of a chicken, squirrel, rabbit, or other small animal used for food. Observe, first of all, the external covering, consisting of cuticle and hair, claws, scales, or feathers, according to the specimen. These are similar in structure, and they form the epidermis, which is one kind of epithelial tissue. With a sharp knife lay open the skin and observe that it is attached to the parts underneath by thin, but tough, threads and sheaths. These represent a variety of connective tissue. The reddish material which forms the greater portion of the specimen is a variety of muscular tissue, and its divisions are called muscles. With a blunt instrument, separate the muscles, by tearing apart the connective tissue binding them together, and find the glistening white strips of connective tissue (tendons) which attach them to the bones. Find near the central part of the leg a soft, white cord (a nerve) which represents one variety of nervous tissue. The bones, which may now be examined, form the osseous tissue. At the ends of the bones will be found a layer of smooth, white material which represents one kind of cartilaginous tissue. The adipose, or fatty, tissue, which is found under the skin and between the other tissues, is easily recognized.

Relation of the Tissues to the Organs. - Observe in the specimen just studied the relation of the different tissues to the organ as a whole (regarding the leg as an organ), show how each of the tissues aids in the work which the organ accomplishes. Show in particulary how the muscles supply the foot with motion, by tracing out the tendons that connect them with the toes. Pull on the different tendons, noting the effect upon the different parts of the foot.

D.C. Heath and Co. - Publishers
Original copyright 1909