Quiz 2 - Epidermis Flashcards
functions of integumentary system
protection body temperature regulation cutaneous sensations (touch and pressure receptors) metabolic functions (ex: vitamin D) excretion immune response
structure of integumentary system
layers: epidermis, dermis, hypodermis
epidermis
stratified, squamous epithelium (keratinized), avascular
layers of epidermis (BSGLC)
stratum basale stratum spinosum stratum stratum granulosum stratum lucidum stratum corneum
stratum basale
deepest layer; single row of cells
- keratinocytes
- basal cells
- merkel cells
- melanocytes
keratinocytes
epithelial cells that produce keratin
basal cells
rapid dividing stem cells, replace superficial keratinocytes at epithelial surface
merkel cells
associated closely with a sensory nerve ending
melanocytes
produce melanin
melanin
pigment that creates a “shield” to protect keratinocytes nucleus from UV radiation damage
stratum spinosum
“spiny” layer - several cell layers think, keratinocytes contain protein filaments that cross-link to adjacent cells
- langerhan’s (dendritic) cells
langerhan’s cells
initiates immune response against pathogens
stratum granulosum
(granular layer) - thin; 3-5 cell layers of flattened keratinocytes
- keratohyaline
- membrane bound granules
keratohyaline
granular protein that surrounds keratin filaments
membrane-bound granules
causes cells to be water resistent
