Integumentary (Accessory Structures) A&P

Nails

• Protective covering

• Nail plate, nail bed, lunula

Hair follicle

• In dermis

• Grows hair

• Prevents heat loss

• Reduces sunburn

• Protects and filters

• Made from modified epidermal cells

Arrector Pili

• Attaches to hair follicles

• When contracted hair stands on end and gives goose bumps

• Stimuli: cold/emotions

Sebaceous Glands

• In dermis, opens into follicles

• Secrete sebum (oil) that keeps skin and hair pliable and “greasy”

Eccrine Sweat Glands

• In dermis and hypodermis, everywhere but lips and genitalia

• Release sweat in response to temperature, causes cooling

• Empty via pores on skin surface

• Merocrine glands

Apocrine Sweat Glands

• In dermis and hypodermis of scilla and groin

• Ducts empty into hair follicles in response to emotional stimuli

• Become active at puberty

• Bacteria on skin is responsible for body odor