, which investigates their functions, or
the special work done in their vital processes.

The word anatomy, however, is usually employed instead of morphology.
It is derived from two Greek words, and means the science of dissection.
Human anatomy then deals with the form and structure of the human
body, and describes how the different parts and organs are arranged, as
revealed by observation, by dissection, and by the microscope.

Histology is that part of anatomy which treats of the minute
structure of any part of the body, as shown by the microscope.

Human physiology describes the various processes that go on in the
human body in health. It treats of the work done by the various parts of
the body, and of the results of the harmonious action of the several
organs. Broadly speaking, physiology is the science which treats of
functions. By the word function is meant the special work which an
organ has to do. An organ is a part of the body which does a special
work. Thus the eye is the organ of sight, the stomach of digestion, and
the lungs of breathing.

It is plain that we cannot understand the physiology of our bodies without
a knowledge of their anatomy. An engineer could not understand the working
of his engine unless well acquainted with all its parts, and the manner in
which they were fitted together. So, if we are to understand the
principles of elementary physiology, we must master the main anatomical
facts concerning the organs of the body before considering their special
functions.

As a branch of study in our schools, physiology aims to make clear certain
laws which are necessary to health, so that by a proper knowledge of them,
and their practical application, we may hope to spend happier and more
useful, because healthier, lives. In brief, the study of hygiene, or
the science of health, in the school curriculum, is usually associated
with that of physiology.[1]

6. Chemical Elements in the Body. All of the various complex
substances found in nature can be reduced by chemical analysis to about 70
elements, which cannot be further divided. By various combinations of
these 70 elements all the substances known to exist in the world of nature
are built up. When the inanimate body, like any other substance, is
submitted to chemical analysis, it is found that the bone, muscle, teeth,
blood, etc., may be reduced to a few chemical elements.

In fact, the human body is built up with 13 of the 70 elements, namel