Flashcards in Ch. 5 Deck (58)
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1
what are the two later of the skin
epidermis and dermis
2
what is hypodermis composed of
areolar an adipose tissue
3
what are the 5 important functions of the skin
protection, body temperature regulation, excretion, production of vitamin D, sensory reception
4
what are the 4 main cell types found in the epidermis
keratinocytes, melanocytes, tactile epithelial cells, dendritic cells
5
keratinocytes
located in stratum spinosum produce keratin, fibrous protein
6
melanocytes
found in basal layer; manufacture and secrete pigment
7
tactile epithelial cells
found in basal layer; attached to sensory nerve endings
8
dendritic cells
found in stratum spinosum; part of immune system; macrophage-like
9
what are the layers of the epidermis
stratum basale, stratum spinosum, stratum granulosum, stratum lucid (only in thick skin), stratum corneum
10
what happens in the stratum basale
cells actively divide
11
what does the stratum basal contain
tactile epithelial cells and melanocytes
12
what does the stratum spinosum contain
thick bundles of intermediate filaments, dendritic cells
13
what does stratum granulosum consist of
few layers of keratinocytes
14
what do keratinocytes contain
keratohyaline granules- help form keratin, lamellar granules-contain waterproofing glycolipid
15
descrie stratum lucidum
occurs only in thick skin (palms and soles), composed of a few rows of flat, dead keratinocytes
16
describe the stratum corneum
thick layers of dead keratinocytes and thickened plasma membranes, protects skin against abrasion and penetration
17
what are the two layers of the dermis
papillary dermis (includes dermal papillae) and reticular dermis (deeper layer)
18
describe the papillary dermis
includes dermal papillae, increase surface area for exchange of gases, nutrients, and wastes
19
what are epidermal ridges (friction ridges)
elevation of dermal ridges, AKA fingerprints
20
purpose of epidermal ridges
increases gripping ability of hands and feet
21
cleavage lines
separation b/t collagen fibers
22
flexure lines
deep creases in palms, wrists, soles, finger, and toes
23
what are the two types of vascular plexuses found in the reticular dermis
dermal plexus, and sub papillary plexus
24
what type of tissue is in the hypodermis
areolar and adipose connective tissue
25
function of hypodermis
anchors skin to underlying structures, helps insulate body
26
what is another name for the hypodermis
superficial fascia
27
name the 3 pigments that contribute to skin color
melanin, carotene, hemoglobin
28
what is melanin made of
made from tyrosine
29
carotene
yellowish pigment from carrots and tomatoes
30