BIOL 212 Lecture Notes - Lecture 4: Stratum Spinosum, Stratum Lucidum, Stratum Corneum
Document Summary
Constrict blood vessels (less blood to surface: 2. Contraction of dermal muscles (arrector pili) (--> heat; goosebumps: b. Dilate blood vessels (more blood to surface: 2. Vitamin d synthesis: aging in the integument, 1. Decreased mitosis of all cells: fewer cells so layers get thinner, fewer cells so less hair, fewer glands, wbc, capillaries, melanocytes, 2. Decrease in function of cells: decreased matrix and fibers in ct, decreased sweat, oil, pigmentation, 3. Fewer melanocytes: pale skin, reduced tolerance for sun exposure, 4. Dry epidermis: reduction in sebaceous and sweat gland activity, 5. Thin epidermis: slow repairs, decreased vitamin d production, reduced # of langerhans cells, 6. Reduced sweat gland activity: tendency to overheat, 7. Thin dermis: sagging and wrinkling due to fiber loss, 8. Reduced blood supply: slow healing, reduced ability to lose heat, 9. Changes in distribution of fat and hair: due to reduction in sex hormone levels, 10. Fewer active follicles: thinner, sparse hairs, general characteristics, 1.
