quiz 4 Flashcards
darker skin tone in areas of greater sunlight, lighter skin tones found in areas that have least amount of sunlight
geographic distribution
dark skin tones serve to protect against cell damage due to?
excessive ultraviolet radiation
absorbs ultraviolet radiation and prevents excessive amounts of stratum germinativium and dermis
melanin
presence of a thicker stratum corneum also prevents excessive (uvr) from reaching the _____ _____ _____
lower mitotic cells
melanocytes respond to increased amounts of ultraviolet radiation by producing melanin
tanning
you get vitamin D from?
UVR reaching the deeper skin layers to facilitate to facilitate this chemical process
dark skin in low UVR exposure
decreased production of vitamin D
necessary for bone growth
Vitamin D
lack of vitamin d leads too
a deficiency in rickets in children, and osteomalacia in adults
True or False: are dark skin people more sucepatable to damage in by extreme cold than light skin
true
reside in the dermis and subcutaneous layer, but originate from epidermal tissue; hair is present on nearly all human skin surfaces, but primarily is short and very fine
hair and the hair follicle
houses the hair
Follicle
zone of actively dividing cells at the base of the hair
bulb
a column of flattened, dead keratinized cells within the follicle
Root
a column of flattened, dead keratinized cells external to the skin’s surface
Shaft
Muscle attached to hair follicle surface and to the dermis; also responsible for goosebumps
Arrector pili muscle
modified hardened stratum corneum; divisible into nail root, nail body, and free edge
nail plate
underlying the nail plate; continous with stratum basal and stratum spinosum of surrounding epidermis
nail bed
part of the nail plate; light half moon region at the proximal end of the nail plate, due to extreme thickness of underlying nail bed
Lunula
holocrine gland; secretes sebum which lubricates and waterproofs hair and stratum corneum; alveolar in shape, connected to the hair follicle
sebaceous gland
odoriferous merocine sweat gland, concentrated in axillary and pubic regions; responds to emotional stress; tubular in shape, connected to the hair follicle
Apocrine
merocrine sweat gland, found all over the body, especially in the forehead,back, palms, and soles; functions in evaporative cooling, plus excretion of certain bodily wastes; tubular shape, exits directly onto the surface of the skin
Eccrine
