1. Hair2. Skin glands3. Nails

Accessory Organs of the Skin

A. Forms from epidermal cellsB. Housed in the hair follicleC. 2 distinct sections

1) Shaft – portion that projects from skin surface

2) Root – deep portion penetrating the dermis

D. Arrector pili muscles1) Smooth muscle attached to each hair follicle2) Contract when stimulated by cold or nervous impulses,

pulling hair up straight and causing goosebumpsE. Hair root plexus – dendrites of neurons that are sensitive to

touch

1. Hair

A. Sebaceous glands1) “seb ” = grease2) Oil-producing (Why do we want this?)3) Usually associated with hair follicles in the dermis4) Keep hair and skin soft, pliable, and waterproof

B. Sudoriferous glands1) “sudori ” = sweat; “ferous ” = bearing2) 2 main types

a) Eccrine – secretes cooling sweat directly onto the skinb) Apocrine – stimulated during stress/excitement; secreted

into hair follicles3) Modified sweat glands

a) Ceruminous (“cer ” = wax) – external ear canalb) Mammary –- milk-producing

2. Skin Glands

• Made of tightly packed, keratinized (???) epidermal cells

• Consists of:– Nail body – visible portion– Free edge – part that extends past the end of the

digit– Nail root – portion buried in a fold of skin– Lunula (“little moon”) – crescent-shaped area of

the nail

3. Nails

1. Protective covering– Prevents water loss– Keeps microbes and contaminants out

2. Cutaneous sensation – gathers information of environment

3. Excretion and absorption4. Synthesis of vitamin D5. Wound healing6. Temperature regulation

Functions of Integument

• When body temperature is too high:– Blood vessels in the dermal area dilate, so heat

can be released to the environment.– Sweat glands are stimulated, and the

evaporating sweat cools the body.

• What happens when the body is too cold?

Temperature Regulation