skin and lymph Flashcards
what are the regions of the skin
1.epidermis: thick superficial layer
2. dermis: deep fibrous CT
3. hyperdermis: loose areolar and adipose, deepest to skin
functions of the skin
-protection
-body temp regulation
-excretion
-vitamin D production
-sensory reception
epidermis
4 cell types
-keratinocytes
-melanocytes
-tactile epithelial cells
-dendritic cells
epidermis
keratinocytes
location: spiny layer
function: produce keratin, fibrous protein that provides mechanical protection, produces antibiotics and enzymes that detoxify chemicals
epidermis
melanocytes
location: basal layer
function: manufacture and secrete pigment melanin
epidermis
tactile epithelial cells
location: basal layer
function: innervation
epidermis
dendritic cells
location: spiny layer
function: part of the immune system
layers of the epidermis
- stratum basale: deepest
- stratum spinosum
- stratum granulosum
- stratum lucidum (extra)
- stratum corneum
epidermis
stratum basale
deepest layer of the epidermis
attached to the dermis
contains tactile epithelial cells and melanocytes
cells actively divide
epidermis
stratum spinosum
spiny
contain thick bundles of intermediate filaments that resist tension
contain dendritic cells
keratinocytes lost contact with the dermis, lose blood supply
epidermis
stratum granulosum
contains flattened keratinocytes
-keratohyalin granules: help form keratin
-lamellated granules: contain a waterproof glycolipid that helps slow water across the epidermis
epidermis
stratus lucidum
only in thick skin
composed of several rows of flat and dead keratinocytes
epidermis
stratum corneum
outside layer
thick layer of dead keratinocytes
cells are shed
protects
dermis layers
- papillary layer: includes dermal papillae fingerlike projections that extend to the epidermis, and increase SA
- reticular layer: deeper, contain networks of collagen fibers
epidermal ridges come from
dermal papillae
