FUNCTIONS OF THEINTEGUMENTARY SYSTEM
(in-teg-̄u -men′tă -rē ) system
consists of the skin and accessory structures, such as hair, glands, and nails.
Integument means covering, and the integumentary system is one of the more
familiar systems of the body to everyone because it covers the out-side of the
body and is easily observed. We are also familiar with this system because we
are concerned with the appearance of the integumentary system. Skin without
blemishes is considered attrac-tive, whereas acne is a source of embarrassment
for many teenagers. The development of wrinkles and the graying or loss of hair
are signs of aging that some people find unattractive. Because of these
feelings, we invest much time, effort, and money on changing the appearance of
the integumentary system. Many of us apply lotion to our skin, color our hair,
and trim our nails. We also try to prevent sweating by using antiperspirants
and to reduce or mask body odor by washing and by using deodorants and
The appearance of the
integumentary system can indicate physiological imbalances in the body. Some
disorders, such as acne or warts, affect just the integumentary system. Other
dis-orders affect different parts of the body but are reflected in the
integumentary system, providing useful signs for diagnosis. For example,
reduced blood flow through the skin during a heart attack can cause a person to
look pale, whereas increased blood flow as a result of fever can cause a
flushed appearance. Also, some diseases cause skin rashes, such as those
characteristic of measles, chicken pox, and allergic reactions. In addition, the
integ-umentary system and the other systems often interact in complex ways in
both healthy and diseased states (see Systems Pathology, “Burns,” later).
Although we are often
concerned with how the integumentary system looks, it has many important functions
that go beyond appearance. Major functions of the integumentary system include
1.Protection. The skin
provides protection against abrasionand ultraviolet light. It also prevents
microorganisms from entering the body and reduces water loss, thus preventing
integumentary system has sensory receptors that can detect heat, cold, touch,
pressure, and pain.
3.Vitamin D production. When
exposed to ultraviolet light,the skin produces a molecule that can be
transformed into vitamin D, an important regulator of calcium homeostasis.
The amount of blood flow beneath the skin’s surface and the activity of sweat
glands in the skin both help regulate body temperature.
amounts of waste products are lost through the skin and in gland secretions.