Ch. 5 Flashcards
epidermis
epithelium of skin
dermis
connective tissue of skin
hypodermis
connective tissue just underneath skin
thick skin
hairless, no sebaceous oil glands
palms of hands, front of fingers, soles of feet, bottom of toes
adaptive for high friction
thin skin
hairy, has sebaceous oil glands and sweat glands
covers most of the body
functions of skin
resistance to trauma and infection
water retention
synthesis of vitamin D
thermoregulation
nonverbal communication
epidermis details
keratinized stratified squamous epithelium
avascular
sparse nerve endings
cells of epidermis
keratinocytes, stem cells, melanocytes, tactile (Merkel) cells, dendritic cells
keratinocytes
synthesize keratin
vast majority of epidermal cells
stem cells
divide and produce keratinocytes
only in stratum basale
melanocytes
make melanin
found in stratum basale
tactile (merkel) cells
touch receptors that join with nerves
only found in stratum basale
dendritic (langerhans) cells
immune surveillance
found in stratum spinous and stratum granulosum
layers of epidermis
stratum corneum
stratum lucid
stratum granulosum
stratum spinosum
stratum basale
stratum corneum
several layers of dead, scaly cells
stratum lucidum
only in thick skin, cells lack organelles
stratum granulosum
cells have dark granules
stratum spinosum
several layers of cells, often the thickest layer in the epidermis
stratum basale
only one cell thick, varied cell types
dermis
rich in collagen fibers
large blood supply
cutaneous glands, hair follicles, arrestor muscles, and nail roots
layers of dermis
papillary layer
reticular layer
papillary layer
superficial, thin
areolar tissue
blood vessels
reticular layer
deep, thick
dense irregular connective tissue
striae - stretching of collagen
hypodermis
not true layer of skin
below dermis
adipose and areolar tissue
functions:
-energy storage
-thermal insulation
-connection to deeper tissue
