Chapter 5 Flashcards
what does integumentary system do?
separates/protects from external environment.
-sensation, temp reg, Vitamin D, excretion of small amount of waste products
Epidermis is what epithelium
stratified squamous epithelium, divided into 5 strata (regions)
stratum basale
keratinocytes (product cells of superficial strata)
stratum spinosum
several layers of cells held together by desmosomes
stratum granulosum
cells filled with granules of keratohyalin.
cell death occurs.
stratum lucidum
layer of dead, transparent cells
stratum corneum
consists of many layers of dead squamous cells. most superficial cells slough off.
keratinization
transformation of living cells of stratum basale into dead squamous cells of stratum corneum
- keratinized cells have protective barrier - structural strength. cells not shed.
thick skin
has all 5 epithelial strata
thin skin
contains less layers per stratum. hair is only found here. stratum lucid is usually absent.
melanocytes
produce melanin inside melanosomes and transfer melanin to keratinocytes. size/distribution of melanosomes determine skin color. genetic but influenced by UV and hormones.
carotene
ingested plant pigment, causes skin to be yellowish
red skin color
-increased blood flow
cyanosis
- decreased blood flow / decreased oxygen
-pale/ blue skin
dermis
connective tissue, 2 layers: papillary and reticular
papillary layer
layer of dermis.
-projections called dermal papillae, composed of loose connective tissue and capillaries
reticular layer
-main layer of dermis
-dense irregular connective tissue consisting mostly of collagen