BISC 3221 Chapter Notes - Chapter 4: Tretinoin, Calcitriol, Merocrine

• School: Fordham University
• Department: Biological Sciences
• Course: BISC 3221
• Professor: Craig Frank

Document Summary

4. 2 the epidermis: stratified squamous epithelium, four cells types: keratinocytes, melanocytes, merkel cells, Thick and thin skin: thin skin: four layers, covers most of body, stratum corneum a few cell layers deep, thick skin: palms, soles, 30 or more layers of keratinized cells. Epidermal ridges: epidermal ridges: from stratum basale, increases area of contact, dermal papillae: projections from dermis toward epidermis, extend between ridges, ridges on palms and soles increase sa and friction, for grip (genetically determined shapes) In keratinocyte, melanin is closest to nucleus: melanocytes respond to uv is mto increase rates of melanin production/transfer. 4. 3 the dermis: deep to epidermis, 2 main components: superficial papillary, deeper reticular layer. In both, backs of hands and upper surfaces of feet, abdominal region: elastic, only superficial region has large arteries/veins, the rest has limited capillaries and no vital organs (subcutaneous injection useful for injections i. e. hypodermic needles)