The human skin is composed of three different layers. Known as the integumentary system, the skin is considered an organ, the largest of the body. Without it, living would be impossible. It holds moisture in the body, regulates temperature, acts as a protective layer against the outside world and contains many sensory nerves to warn you of dangerous conditions you encounter.
Epidermis
The epidermis consists of five stratums or layers. They include stratum corneum, stratum lucidium, stratum granulosum, stratum spinosum and stratum basale. The Southern Illinois University Medical School explains these layers are avascular and contain pores and hair shafts that transverse to the lower layers of skin. The stratum basale is the layer where cells multiply. Cells formed in this layer migrate upwards to the outer layer and the older cells slough off, forming new skin. The basale layer attached to the basement membrane; contain melanocytes, Langerhan cells and Merkel cells.
Dermis
The dermis layer contains blood vessels, nerve endings, deep sensory receptors, hair follicles, sweat glands, sebaceous glands and the erector pilli muscle that makes the hair stand on end. It is composed of collagen a type of connective tissue. According to Holistic Online, the health of the collagen determines the health of the skin. Collagen holds moisture and prevents wrinkles. As you age, collagen deteriorates causing wrinkles and poor skin.
Hypodermis
Under the dermis lies the hypodermis. It is composed of fat, insulating the body against temperature variations, providing padding and storing energy. Fat is contained in cells, called adipocytes, bonded by fibrous material. Energy is stored in the adipocytes until needed by the body.
Facial Skin
Facial skin has the same basic components as body skin with some minor differences. Facial skin has a thinner fat layer than skin of the body. It can range from a fraction of an inch in the facial area to two or more inches in the abdominal area. Women have smooth facial skin as opposed to more rugged in men. However, men have hair follicles where women have next to none. Wrinkles are more prominent on the face and neck than the rest of the body due to the thinner fat layer.
Hands and Feet
Skin on the hands and feet contain many more nerve endings than skin of the body. These nerves are what accounts for your exceptional tactile senses. Skin of the feet and hands contain no hair follicles and a thin fat layer. The keratinocytes are more active due to the friction, causing the formation of calluses.
