Introduction
Your skin is the largest and one of
the most important organs of your body which performs some essential functions
such as protection, hydration, sensation and temperature regulation. The
internal structure of your skin, however, is even more interesting. Let’s
discover some of the main structural features of your own skin:
Layers of skin
Your skin is composed of two main
layers, the epidermis and dermis, that both rest on the subcutaneous
(underlying) tissues.
Epidermis: It is the outer (or
uppermost) layer of the skin and is made up of outer dead skin cells and deeper
living cells. The melanocyte (special cells) within the epidermis produces
melanin giving color to the skin and helps protect it from ultraviolet light
Dermis: The dermis is found
beneath the epidermis and makes up bulk (90 percent) of your skin.
Subcutaneous
layer: The
epidermis and dermis sit on the subcutaneous (subcutaneous = beneath the skin)
layers, composed largely of fat, through which the blood vessels and nerves
run. The roots of the oil and sweat glands are located here.
Glands of
skin
There are two main types of glands in
your skin:
Sebaceous oil
glands: These
are distributed throughout the skin but are mostly concentrated in the scalp,
face, mid-chest, and genitals. They are attached to the hair follicles and
secrete an oily substance (sebum) that lubricates and protects the skin.
Sweat glands: These glands are
distributed throughout the body but their greatest number is found in the
palms, soles of the feet, forehead, and underarms. They secrete at times of
stress, emotion, or in the presence of a warmer environment.
Special structures of skin
Hair: Each hair grows from a
single follicle that has its roots in the subcutaneous tissue] of the skin. The
oil glands next to hair follicles provide gloss and, to some degree, waterproofing
of the hair. Hair also contains melanin. The number of melanin granules in the
hair determines its color. Malnutrition can cause damage to the hair.
Fingernails
and toenails:
These are part of the epidermis and are composed of the protein, keratin. Each
nail grows outward from a nail root that extends back into the groove of the
skin. With malnutrition, after an injury, or chemotherapy, the nail formation is
impaired.
Types of skin
Depending on your family (heredity),
your genetic make-up and your lifestyle, you skin can be of one of the
following types:
Oily skin: Oily skin is caused by over
activity of the sebaceous glands. Oily skin is thick with large pores and has a
greater tendency to develop acne, but not wrinkles. Most people, who have oily
skin, also have oily hair.
Dry skin: Dry skin is caused by under
activity of the sebaceous glands, environmental conditions, or normal aging.
Dry skin is usually thinner and more easily irritated. There is a greater
tendency to develop wrinkles, but not acne.
Balanced Skin: Balanced skin is neither
oily nor dry. It is smooth and has fine texture –– with few problems. However,
it has a tendency to become dry as a result of environmental factors and aging
Combination
Skin: Combination skin consists of oily regions, often
on the forehead and around the nose, and regions that are balanced or dry.
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