chapter 5: integumentary system Flashcards
31= lab, beyond 31= lecture
what are 2 basic structures of the skin?
epidermis and dermis
they are cemented together
which layer is immediately deep to the dermis?
subcutaneous layer/ hypodermis
what is subcutaneous layer primarily composed of?
adipose tissue
what is the structure of the epidermis?
keratinized stratified squamous epithelium
Name the 4 cells of the epidermis
keratinocytes
melanocytes
dendritic
tactical epithelial
describe keratinocytes
produce keratin(fibrous protein that gives epidermis durability and protective capabilities)
describe melanocytes
spidery black cells that produce brown-black pigments called melanin
dendritic cells
aka langerhans cells
arise from bone marrow and migrate to epidermis
ingest foreign substances and play key role in activating immune system
tactile epithelial cells
spikey hemispheres that form sensitive touch receptors located at epidermal-dermal junction
what are the 4 (5) layers of epidermis?
stratum corneum (horny layer)
(stratum lucidum (clear layer))
stratum granulosum (granular layer)
stratum spinosum (spiny layer)
stratum basale (basal layer)
describe stratum corneum
aka horny layer
has 20-30 dead, scalelike, keratinocytes
constantly being exfoliated and replaced
describe stratum lucidum
aka clear layer
present only on thick skin, palm of hand sole of feet
describe stratum granulosum (2)
aka granular layer
has abundant granules
1. lamella granules: has waterproofing glycolipids secreted into extracellular space
2. keratinohyaline granules: helps form keratin in superficiaal layers
describe stratum spinosum
aka spiny layer
thick weblike bundles of intermediate filaments made of pre keratin protein
called spiky bc when the tissue is prepared, cells shrink, but desmosomes hold tight to adjacent cells.
receives adequate nourishment from diffusion of nutrients from dermis
describe stratum basale
aka basal layer
single row of cells immediately above dermis
constantly undergoing mitosis to form new cells
10-25% are melanocytes
receives adequate nourishment from diffusion of nutrients from dermis
what are the 2 parts of the dermis?
describe them
- papillary dermis: superficial region
made of areolar connective tissue
dermal papillae attach to epidermis above (hence fingerprints) - reticular dermis: deepest skin layer
has irregular dense tissue
contains many artieries and veins.
carotene
yellow-orange pigment present in stratum corneum and adipose tissue
cyanotosis
bluish cast when blood is poorly oxygenated, like in asphyxiation
jaundice
tissues become yellowed, diagnosis of liver disease
addisons disease
bronzing of the skin, adrenal cortex is hypoactive
name all nail parts (9)
nail plate
free edge
hyponychium
nail root
nail folds
eponychium
nail bed
nail matrix
lunule
primary hair regions (2)
- hair shaft: region projecting from surface of skin
- hair root: beneath the surface and is embedded in the hair follicle
layers of hair shaft and hair root (3)
medulla: center
cortex: surrounds medulla
cuticle: protective
hair follicle
in both epidermal and dermal
epithelial root sheath is enclosed by basement membrane, glassy membrane peripheral connective tissue sheath (essentially dermal tissue)
