What Is The Primary Function Of Our Skin?

The skin is the body'southward largest organ. It serves many important functions, including

Protecting the body against trauma
Regulating body temperature
Maintaining water and electrolyte remainder
Sensing painful and pleasant stimuli

The skin has three layers:

Epidermis
Dermis
Fatty layer (also called the subcutaneous layer)

Each layer performs specific tasks.

Getting Under the Pare

The skin has iii layers. Beneath the surface of the pare are nerves, nerve endings, glands, hair follicles, and blood vessels. Sweat is produced past glands in the dermis and reaches the surface of the skin through tiny ducts.

The epidermis is the relatively sparse, tough, outer layer of the pare. About of the cells in the epidermis are keratinocytes. They originate from cells in the deepest layer of the epidermis chosen the basal layer. New keratinocytes slowly migrate up toward the surface of the epidermis. Once the keratinocytes reach the skin surface, they are gradually shed and are replaced by newer cells pushed upwardly from below.

The outermost portion of the epidermis, known as the stratum corneum, is relatively waterproof and, when undamaged, prevents most bacteria, viruses, and other foreign substances from entering the body. The epidermis (along with other layers of the peel) also protects the internal organs, muscles, nerves, and claret vessels from injury. In certain areas of the body that require greater protection, such as the palms of the hands and the soles of the anxiety, the stratum corneum is much thicker.

Scattered throughout the basal layer of the epidermis are cells called melanocytes, which produce the pigment melanin, one of the principal contributors to peel color. Melanin'south primary function, however, is to filter out ultraviolet radiations from sunlight (see Overview of Sunlight and Peel Impairment Overview of Sunlight and Skin Damage Sunlight stimulates vitamin D production, helps control some chronic skin diseases (such equally psoriasis), and causes a sense of well-being. However, sunlight can crusade skin damage. Damage includes... read more Overview of Sunlight and Skin Damage ), which damages DNA, resulting in numerous harmful furnishings, including pare cancer Overview of Skin Cancer Skin cancer is the well-nigh common blazon of cancer. Skin cancer is most common amongst people who piece of work or play sports outside and among sunbathers. Fair-skinned people are particularly susceptible... read more .

The epidermis also contains Langerhans cells, which are role of the peel's immune arrangement. Although these cells help discover foreign substances and defend the body against infection, they besides play a role in the development of peel allergies.

The dermis, the skin's next layer, is a thick layer of fibrous and elastic tissue (made mostly of collagen, with a pocket-size simply important component of elastin) that gives the peel its flexibility and strength. The dermis contains nerve endings, sweat glands and oil glands (sebaceous glands), hair follicles, and blood vessels.

The nerve endings sense pain, bear on, pressure, and temperature. Some areas of the pare comprise more than nerve endings than others. For case, the fingertips and toes incorporate many nerves and are extremely sensitive to bear on.

The sweat glands produce sweat in response to rut and stress. Sweat is equanimous of water, salt, and other chemicals. As sweat evaporates off the skin, information technology helps cool the body. Specialized sweat glands in the armpits and the genital region (apocrine sweat glands) secrete a thick, oily sweat that produces a feature body olfactory property when the sweat is digested by the skin bacteria in those areas.

The sebaceous glands secrete sebum into hair follicles. Sebum is an oil that keeps the pare moist and soft and acts as a barrier against foreign substances.

The pilus follicles produce the various types of pilus found throughout the body. Hair not but contributes to a person'southward advent but has a number of of import physical roles, including regulating body temperature, providing protection from injury, and enhancing sensation. A portion of the follicle also contains stalk cells capable of regrowing damaged epidermis.

The blood vessels of the dermis provide nutrients to the skin and aid regulate body temperature. Heat makes the blood vessels enlarge (dilate), allowing big amounts of blood to broadcast near the peel surface, where the heat can exist released. Cold makes the claret vessels narrow (constrict), retaining the body's rut.

Over different parts of the body, the number of nervus endings, sweat glands and sebaceous glands, hair follicles, and blood vessels varies. The elevation of the head, for example, has many pilus follicles, whereas the soles of the feet have none.

Below the dermis lies a layer of fat that helps insulate the body from heat and cold, provides protective padding, and serves equally an free energy storage area. The fat is contained in living cells, called fat cells, held together by fibrous tissue. The fat layer varies in thickness, from a fraction of an inch on the eyelids to several inches on the abdomen and buttocks in some people.