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.