Exam 1 Part 6 Flashcards
Integument
cutaneous membrane
largest organ in body
Integumentary system
skin and derivities
hair, glands, nails, sensory endings
derma
skin
functions of integumentary system
protection hydroregulation temperature regulation Vitamin D synthesis immune response sensory reception Excretion (oils, sweat)
integument tissue layers
Epidermis
Dermis
Subcutaneous (not part of the system)
Epidermis
ET. outer, subdivided into 4-5 structural layers
keratinized, stratifed squamous ET
most cells are dead (or dying)
airs and glands arise from epidermis that extends into dermis
Dermis
deeper, subdivided into 2 layers. CT
Subcutaneous
hypodermis. mostly fat and loose areolar CT
binds to muscle
Epidermal layers
Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum
Stratum basale
deepest epidermis layer
stem cells
single layer cuboidal cells on basement membrane
3 main types of stratum basale
keratinocytes
Melinocytes
tactile cells
Keratinocytes
toughened, waterproof skin
-constantly divide; migrate toward surface
cells die as keratin accumulates
Melinocytes
produce pigment melanin
protects against UVR -barrier over nucleus)
tactile cells
Merkel cells. touch
stratum spinosum
some cell division
immune response cells
stratum granulosum
keratinization begins here, immune reponse cells
often appears dakr
stratum lucidum
in thick skin only
Stratum corneum
outer most epidermal layer
cells all cornified (drid and flattened keratinized cells) are dead
especially thick on palms of hands and soles of feet
forms calluses and nails
dermis
irregular CT. mainly collagen and some areolar CT
cuts parallel to collagen fibers heal more quickly
deeper, thicker than epidermis
Dermal papillae
Dermal papillae
interface with epidermal ridges to create finger and toes prints (friction ridges)
Dermis also contains:
blood vessels nerves glands (epidermal deriviatives) hair follicles arrector pili muscles
sweat glands
sudoriferous glands
Tattoos are in
the dermis
1st degree burn
in epidermis
