Chapter 15: Body Systems Lesson One: Integumentary System

FUNCTIONS OF THE SKIN Protective covering for the body Barrier between vital organs and outside world (viruses, bacteria, temperature)

Regulates body Temperature Blood vessels enlarge when hot and radiate heat. Sweat also cools the skin when it evaporates. Blood vessels constrict or narrow to conserve heat.

Enabling you to sense the world around you (Sense of touch; pain, pressure and temperature)

STRUCTURE OF THE SKIN TWO MAIN LAYERS Epidermis – outer thin layer Dermis – inner thicker layer

MELANIN – pigment that gives color to the skin, eyes, and hair; produced by cells in the epidermal layer.

ATHLELTE’S FOOT Caused by the same fungus as ringworm Highly contagious: Occurs between toes and is associated with wearing shoes and sweating.

OTHER PROBLEMS OF THE SKIN RINGWORM- Common fungal infection that affects various parts of the body.

BOILS- inflamed pus-filled area of the skin: usually an infected hair follicle.

WARTS- Contagious growths on the outer layer of skin. Caused by viruses.

MOLES- small round, thick, dark spots on the skin. Usually harmless, but if changes in them occur, see a doctor.

PSORIASIS- skin disease in which thickened patches of inflamed red skin form, often covered by white flaking scales. Cause unknown.

VITILIGO – disorder in which patches of skin lose their color. These areas are sensitive to sunlight. Caused by absence of skin cells that produce melanin.

IMPETIGO – Caused by bacteria entering small breaks in the skin. Highly contagious.

BLISTERS – raised areas filled with a watery fluid. Should be covered and left to heal on its own. Can become infected if broken.

CALLUS – An area of thickened skin that results from constant friction or pressure.

CORN – A callus on a toe caused by the pressure from a tight-fitting shoe.