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59 Cards in this Set
- Front
- Back
4 cell types of epidermis
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keratinocytes
melanocytes merkel cells langerhans' cells |
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keratinocyte function
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produce keratin
produce antibiotics and enzymes that detoxify harmful chemicals |
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melanocyte function
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produce melanin, dark skin pigment
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light-skinned people vs. dark-skinned people
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light-skinned people: melanin digested by lysosyme a light distance above basal layer
dark-skinned people: no digestion occurs and melanin occupies distance above basal layer |
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merkel cells function
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serve as receptor for touch
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langerhans' cell function and location
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police outer body surface, using receptor-mediated endocytosis to take up foreign proteins that invaded epidermis
found in stratum spinosum |
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layers of epidermis (deep--> superficial)
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stratum basale
stratum spinosum stratum granulosum stratum lucidum stratum corneum |
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Functions of Skin
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protect body from bumps, scrapes, cuts, microorganisms
screens out UV rays synthesize vitamin D insulates/cushions underlying body tissue protects body from water loss helps regulate body temperature excretes wastes contains sense organs |
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location of tonofilaments
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stratum spinosum
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layers where mitosis occurs
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mostly stratum basale, but also in stratum spinosum
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function of stratum granulosum
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contain keratohyaline and lamellated granules
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function of lamellated granules
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slows water loss
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function of stratum corneum
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protection against penetration and abrasion
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cells of dermis
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fibroblasts, macrophages, mast cells, white blood cells
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function of dermis
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binds body together
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fibers of dermis
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collagen, reticular, elastic
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plexus
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network of converging and diverging vessels
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cutaneous plexus function and location
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between hypodermis and dermis
nourishes hypodermis and structures in deeper portions of dermis |
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subpapillary plexus function and location
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below dermal papillae
supplies more superficial dermal structures |
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function of vascular plexuses
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thermal regulation
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layers of dermis and connective tissue found in it
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superficial papillary layer composed of areolar connective tissue
deeper reticular layer composed of dense irregular connective tissue |
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function of dermal papillae
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tighten connection between epidermis and dermis
increase surface area for diffusion of nutrients and oxygen |
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function of epidermal ridges
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gripping
contain sweat pores along crest--> fingerprints |
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striae
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silvery-white scars from tearing of collagen due to "extreme stretching" of skin
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hypodermis consists of which tissues?
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areolar and adipose connective tissue
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function of hypodermis
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anchors skin to underlying structures
helps insulate body |
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what happens to hypodermis with weight gain?
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thickens
females- breast and thighs males- anterior abdomen |
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contributions to skin color
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3 pigments: carotene, melanin, hemoglobin
and Vitamin D |
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what amino acid is melanin made of?
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tyrosine
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what varieties of melanin are there?
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yellow, red, brown, black
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freckles
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localized accumulation of melanin in basal layer of epidermis due to exposure to sun
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moles
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localized accumulation of melanin in basal layer of epidermis and top layers of dermis that transform into melanin-containing cells
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where does carotene accumulate?
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stratum corneum of epidermis
fat of hypodermis |
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function of Vitamin D
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required for uptake of calcium from diet
production stimulated by UV rays |
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where are sebaceous glands NOT found?
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palms and soles
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function of sebum
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lubricant to keep skin soft and moist
keep hair from becoming brittle |
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blackheads
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accumulations of dried sebum and bacteria in oil duct
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acne
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active infection of sebaceous glands
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holocrine secretion
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whole cells break up to form product
-how sebum made |
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sweat
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blood filtrate released via exocytosis
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function of sweat
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acidic--> retards growth of bacteria on skin
thermoregulation (in mammals) |
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true sweat composition
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99% water
1% salt and metabolic wastes |
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Eccrine glands and its location
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produce true sweat
on palms, soles, forehead |
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apocrine glands and its location
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produce yellow, milky colored sweat
on axillary, anal, genital areas |
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correlation between apocrine glands and puberty?
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apocrine glands function at puberty under influence of androgens
- enlarge and recede with phases of women's menstural cycle - activity increases with sexual foreplay - analogous to sexual scent glands of other animals |
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3 concentric layers of hair
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composed of keratinocytes
medulla cortex cuticle |
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medulla
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central core, consist of large cell and air spaces
only found in thick hair cells |
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cortex
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surrounds medula
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cuticle
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outermost layer--> overlap like shingles to prevent matting of hair
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composition of wall of hair follicle
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outer connective tissue root sheath
inner epithelial root sheath |
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parts of every nail
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distal free edge
body proximal root |
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distal free edge
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grows past skin layer
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proximal root
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tucked into cuticle
actively growing part of nail |
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nail bed
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bed of epidermis the nail rests on
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eponychium
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aka cuticle
proximal nail fold |
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chief parts of hair
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root
shaft |
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hair follicles
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tubular invaginations of epidermis that extend from epidermis to skin
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hair bulb
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deep expanded end of hair follicle
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root plexus
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knot of sensory nerves around hair bulb
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