BIOL 2021 Lecture Notes - Lecture 5: Squamous Cell Carcinoma, Hematoma, Collagen
15 Apr 2016
School
Department
Course
Professor
Document Summary
Shield cell nuclei from uv rays and absorb them. As rays are absorbed, melanin is secreted, travels through epidermal layers, and becomes a suntan. Darker skin results in vitamin d deficiency in more northern areas. Freckles result from sun exposure: they are chewed up by lysosomes. Moles are clusters of melanin that have buried deeper in the dermis: they are not the result of sun. layers (order: can"t lose good southern bananas) Stratum corneum= hard, dead layer (shedded skin). Stratum granulosum= keratinocytes contain glycolipid that allows waterproofing. Attaches to underlying dermis. callus: epidermis thickening from friction blister: separation of epidermis from dermis by fluid-filled pocket. Dermal ridges are what create palm prints, footprints (genetically determined) used for gripping reticular layer. Dense irregular connective tissue (ideal for strength and extensibility in different directions) Stretch marks result from ripping of the collagen fibres. Movement of fetus during development results in reticular layer of dermis.
