Skin (Integumentary System)
Integumentary System:- 1. protection mechanical chemical bacterial UV desiccation. 2. temperature homeostasis sweat glands, flushing arrector pili, pale. 3.cretion affects fluid & electrolyte balance sweat glands release: water, salts, ammonia oil glands release: lipids, acids. 4. sensation touch (light touch, wind, etc) pressure heat cold pain. 5. synthesis vitamin D precursor passes through capillaries in skin and light converts it to vitamin D. 6. nonverbal communication eg. humans and other primates have much more expressive faces than other animals. Layers of Skin : 1) Epidermis 2) Dermis 3) Hypodermis Epidermis Stratified squamous epithelium upper layers dead, filled with keratin (waxy protein) lower layers living cells replaced every 35-45 days subdivided into 5 identifiable layers: 1) Stratum Basale: Lowermost layer of epidermis single cell layer thick only cells that get adequate nutrition and oxygen by diffusion from tissues below...