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Unformatted text preview: pigment produced by melanocytes in stratum basale
& stratum spinosum Skin color (cont.)
Melanin (cont)• Synthesis stimulated by UV radiation (sunlight) & genetics
• [melanocytes] in freckles, moles, dorsal surfaces of hands/feet,
nipples, anus, scrotum, penis, etc.
• Yellow, brown, black and reddish hues
• Suntan fades because……? 7 ‘abnormal’ colors= cyanosis, erythema, jaundice,
bronzing, pallor, albinism, hematoma
Cyanosis= blueness from deficiency of O2 in blood
• Blocked airways, drowning, heart attack, cold weather Erythema= redness due to dilated cutaneous vessels or
dermal pooling of blood
• Anger, sunburn, exercise, embarrassment Abnormal skin color (cont.)
Jaundice= yellowing of skin/whites of eyes due to
excess of bilirubin in blood
• Liver disease, cancer, hepatitis; premature babies Bronzing= golden-brown color of Addison disease
(deficiency of glucocorticoid hormones of adrenal
Pallor= pale color from lack of blood flow; ‘white of
• Emotional stress, low bld pressure, circulatory shock, cold
temps, severe anemia
temps, Albinism= a genetic lack of melanin
Hematoma= a bruise (visible clotted blood) Skin markings
Hemangiomas (birthmarks)= discolored skin due to
benign tumors of dermal blood capillaries
• Strawberry birthmarks are slightly swollen & disappear in
childhood; port wine birthmarks are flat, d...
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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.
- Fall '08