BIOL 212 Lecture Notes - Lecture 4: Melanin, Stratum Lucidum, Keratinocyte
Document Summary
Biology 212 - lecture 4 - the integumentary system. Dehydration (insensible sweat: leakage between the cell - 1 pint/day) Microorganisms (acidic from oil glands - ph is around 4-6) Langerhaun cells: activates and controls immune cells. Pathway of blood that has capillaries up the surface, can be controlled for the temperature. If very cold, can restrict the blood to vital organs and prevented it from upcoming to the surface or else you lose heat. Constrict blood vessels (less blood to surface) Contraction of dermal muscles (heat to goosebumps) Dilate blood vessels (more blood to surface so we can get rid of the heat) Sweat (evaporative heat loss: when water is evaporated off it takes some of the heat) Uv rays activate precursor in skin that goes to liver and kidneys and brings in vitamin d. Cells being damaged might not be replaced fast enough. Decrease in regeneration with damage: layers, capillaries, and glands.
