BIOL 1117 Midterm: Anatomy and Physiology exam 2
7 Nov 2016
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Skin also known as integument: the integumentary system includes the skin and its accessory organs. The (cid:271)od(cid:455)"s largest a(cid:374)d hea(cid:448)iest organ (15% body mass) Consists of two layers: epidermis: stratified squamous epithelium, dermis: connective tissue layer. Hypodermis: another connective tissue layer below the dermis. Thick skin: on palms and sole, and corresponding surfaces on fingers and toes: has sweat glands, but no hair follicles or sebaceous (oil) glands. Thin skin: covers rest of the body: possesses hair follicles, sebaceous glands and sweat glands. Resistance to trauma and infection: resists and recovers from trauma quickly, keratin: packed into epidermal cells, linked together with desmosomes, increase durability and impermeability, acid mantle (ph 4-6) antibacterial. Other barrier functions: waterproofing: stops water loss and water gain, blocks uv radiation, blocks some harmful chemicals other chemicals (drugs and poisons) can go right through. Vitamin d synthesis: skin first step, liver and kidneys complete process, needed for bone development and maintenance.
