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27 Cards in this Set
- Front
- Back
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single row of cuboidal cells
directly on dermis desmosomes keratin & melanin granules intense mitotic activity innermost layer |
stratum basale/ stratum germinativum
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prickle cell layer
langerhans cells polygonal cells several layers tonofilaments (fibrous pt of keratin) lots of desmosomes mitosis in initial layers only lamellar granules appear |
stratum spinosum
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mitotically active stratum spinosum + stratum basale
(only place to find epidermal stem cells) |
Malpighian layer/ stratum Malpighii
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3-5 layers
flattened polygonal cells keratohyalin granules (blue, coarse) lamellar granules cells begin to die |
stratum granulosum
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what does a lamellar granule do when released?
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makes intercellular spaces impermeable to water
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palms and soles
clear/ glassy cells |
stratum lucidum
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very flattened cells
dead thick cell membrane lack ALL organelles soft keratin |
stratum corneum
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where is most of the melanin found in the epidermis?
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in KERATIN cells -- they engulf it after the melanocytes produce it
also correct: "cells that are more deeply localized/ dividing more actively" |
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what is the difference between a melanin granule and melanosomes?
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there is no tyrosinase activity in a melanin granule
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what are the 2 layers of the dermis?
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papillary (fine collagenous fibers, nn or bv's, interlock dermis to epidermis)
reticular (deep, dense irreg CT, coarse collagen, larger bv's/nn, sm mm or skel mm sometimes) |
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are there reticulocytes in the reticular layer?
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NO!
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what is the primary purpose of the dermis?
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tensile strength via collagen
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deep touch/ pressure
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pacinian corpuscles
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light touch/ pressure
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meisner's corpuscles
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warm temp
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free nerve endings
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cold temp
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free nn endings
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pain
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free nerve endings
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loose irreg CT
lots of fat secretory portion of sweat glands nn Pacinian corpuscles hair roots |
subcutaneous layer
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what is the primary purpose of the subcutaneous layer?
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stabilizes skin while allowing independent movement
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where is hard keratin found?
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hair
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what is the hair papilla?
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highly cellular CT, fills indentation at base of hair
many capillaries, nn has melanocytes INDUCTIVE INFLUENCE on cells of hair matrix |
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what is the mechanism of the secretory portion of the excretory duct of glands?
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NO LUMEN
basal cells undergo mitosis, daughter cells pushed toward center of gland; at the center cells degenerate |
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entire cell lost in process of secretion
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holocrine - sebaceous gland
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what is the difference btw the sweat and sebaceous excretory ducts?
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sebaceous: unbranched, wide, short, strat. sq. epithelium
sweat: long, highly coiled, NO LINING in epidermal portion, strat. cuboidal in dermal & SQ portions |
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what lines the secretory portion of the sweat glands?
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simple; cuboidal to columnar
contractile myoepithelial cells btw base and basal lamina |
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no part of the cell is lost in formation and release of secretory product
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merocrine -- sweat glands
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what are the 2 types of sweat glands and how do they differ?
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eccrine: directly to skin surface, whole body, clear secretion, T regulation
apocrine: empty into hair follicle, armpits/groin/nipples, viscous cloudy bacteria food, pheremones, EMOTIONAL STRESS releases |
