CHP6 The Intugumentary System

Eumelanin moderate of pheomelanins blond sulfur

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Unformatted text preview: e scaly cells scaly Hair texture & color Hair **Intertwining cells lining follicle have free edges facing downward to ‘interlock’ w/ scales of hair cuticle (facing upward) upward) • Thus, hair & layer of follicle cells pull out together Hair texture= cross sectional shape • Straight= round • Wavy= oval Wavy= • Curly (kinky)= flat Hair color= due to pigment granules in cells of cortex • Brown/black= eumelanin (a form of melanin) • Blond= tiny amount of eumelanin, [moderate] of pheomelanins Blond= (sulfur-containing pigment) (sulfur-containing • Red= [slight] of eumelanin, [high] of pheomelanins • White/gray= lack of pigments & air spaces in medulla Hair follicle Hair Follicle structure= diagonal tube into dermis & sometimes diagonal hypodermis hypodermis • 2 llayers= epithelial root sheath & connective tissue root sheath ayers= epithelial connective • Epi r.s.= an extension of epidermis, lies adjacent to hair root • Connective t. r.s.= derived from dermis, surrounds the epithelial Connective sheath sheath Nerve & muscle fibers associated w/ follicles= hair receptors, piloerector muscle receptors piloerector • Hair receptors= nerve fibers that respond to hair movements Piloerector muscle (arrector pili)= bundle of smooth muscle bundle cells extending from dermal collagen fibers to the bulge in root sheath in • Bulge= stem cells of hair growth • SNS stims p. muscle causing hair to stand on end • Cold temps, fear, sti...
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This note was uploaded on 01/12/2014 for the course ZOO 250 taught by Professor Staff during the Fall '08 term at S.E. Louisiana.

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