Part 2 — SUMMARY OF PART II
Reading edition
For the maintenance of life the needs of the cells must be supplied and the body as a whole must be brought into proper relations with its surroundings. The last-named condition requires that the body be moved from place to place; that its parts be controlled and coördinated; and that it be adjusted in its various activities to external physical conditions. To accomplish these results there are employed:
1. The skeleton, or bony framework, which preserves the form of the body and supplies a number of mechanical devices, or machines, for causing a variety of special movements.
2. The muscular system, which supplies the energy necessary for executing the movements of the body.
3. The nervous system, which (a) controls and coördinates the various activities and (b) provides for the intelligent adjustment of the body to its environment. (Review Summary of Part I, page 215, and consult Fig. 92, page 214.)
[pg 422]