The Integumentary System Test: March 10, 2017 All multiple choice/matching Will cover integumentary system, and Dean Vaughn Lessons 7-8

Functions of the Skin A. Protection: the skin is a physical barrier that protects against physical damage, dehydration, UV rays, and pathogenic invasion. B. Body temperature maintenance: the skin contains sweat glands that secrete fluid to help regulate the body’s temperature C. Excretion: during perspiration, small amounts of wastes (salt, water, & organic compounds) are released D. Perception of stimuli: many nerve endings and receptors are contained in the skin that detects stimuli related to temperature, touch, pressure, and pain.

The Skin: Made up of strata that have unique functions in the body A. Epidermis: forms the outermost layer of the skin. The epidermis is made up of epithelial tissue. This type of tissue can also line internal organs and body cavities. Keratin: a fibrous, water-repellent protein Melanocytes: produce melanin pigments. Melanin is responsible for protecting the skin from UV radiation. Different amounts of melanin can lead to different skin colors.

B. Dermis: lies directly below the epidermis B. Dermis: lies directly below the epidermis. It is made up of connective tissue, blood and lymphatic vessels, nerve fibers, hair follicles and sebaceous and sweat glands. Collagen is main component of the connective tissue of the dermis. Gives skin its shape, strength, and elasticity. (Collagen comes from the Greek kolla =glue) C. Subcutaneous Layer (hypodermis): deepest layer of skin situated below the dermis. Connects the skin to the surface of muscles. Important in providing heat insulation and protecting deeper tissues in the body. Lipocytes: cells that manufacture and store fat

Pore of sweat gland Hair shaft Epidermis Sebaceous gl. Arrector pilli Dermis Sweat gland duct Hair follicle Hypodermis Vein Artery Nerve fibers Lipocytes Sweat gland

D. Accessory organs of the Skin a. Glands: cell or groups of cells that secretes specific substances i. Sebaceous: everywhere except palms and soles of feet; secrete sebum, an oily substance, into the hair follicles. It is a slightly acidic substance so prevents bacterial growth. ii. Sweat glands: found on almost all exterior body surfaces. Coiled glands that terminate at openings called pores. Sweat is mostly water but also contains salt and metabolic waste products. The smell produced from sweat occurs when bacteria interact with sweat.

b. Hair: made up of fibers of dead protein cells filled with hard keratin. Connected to the skin via the hair follicle. Arrector pili (small muscle fibers) attach to the hair follicles and can allow your hair to stand up when you’re cold or frightened.

c. Nails: made of hard keratin c. Nails: made of hard keratin. Fingernails cover the dorsal surface of the last bone of each finger. Toenails cover the superior surface of each toe. Many health disorders result in altered growth and appearance of the nails. Basic nail structure: i. Nail plate: translucent part of the nail, which is closely molded to the underlying tissue. ii. Cuticle: narrow band of epithelial tissue attached to the surface of the nail and at the base and sides of the nail plate. iii. Nail root: area of the dermis where the nail rests iv. Lunula: semilunar, white area at the proximal end of the nail

Cuticle Nail Plate Lunula Nail Plate Nail Root

Skin Diseases and Conditions A. Acne: inflammatory disorder of the sebaceous glands that produces pimples on the skin. B. albinism: inherited condition that prevents the normal production of melanin. Results in extremely pale skin and white hair. a. Albin/ism:_____________________________________ Condition of whiteness

C. Burns: injuries to skin tissue caused by prolonged heat contact a. First-degree: superficial epidermal lesions, redness, blisters b. Second-degree: epidermal and dermal lesions, redness, blisters, and hyperesthesia Hyper/esthesia:______________________________________________ c. Third-degree: epidermis and dermis are destroyed, severe hyperesthesia or anesthesia, depending on nerve damage Above normal sensation

D. psoriasis: chronic disease marked by itchy, erythematous skin with silvery patches E. Scleroderma: chronic, progressive disease marked by hardening and shrinking of connective tissue. Causes edema or pain in the muscles or joints.

F. Varicose veins: veins have a twisting appearance due to loss of elasticity G. Vitiligo: Loss of pigment in one or more areas of the skin, creating milky-white patches