(1) Internal environment control. Hormones help control the body's internal
environment by regulating the chemical composition and volume of the body's fluids and
(2) Environmental condition adjustments. Hormones help the body adjust to
changes in the environment. Thanks to various hormones, the body can cope with
emergency demands such as infection, trauma, emotional stress, dehydration,
starvation, hemorrhage, and temperature extremes.
(3) Growth and development.
Hormones are instrumental in regulating the growth and development of the body.
(4) Reproduction. Hormones are very important in the basic process of
reproduction. Various hormones play a significant part in fertilization, nourishment of
the embryo and fetus, delivery, and nourishment of the newborn.
a. Description. The pineal gland is located just posterior to the third ventricle in
the brain. The name was chosen because this gland resembles a pine cone. The
pineal gland starts to calcify (becomes hard due to deposit of calcium salts) at about the
time of puberty. These calcium deposits are referred to as brain salts.
Figure 1-2. The pineal gland and the pituitary gland.