Layers
Two layers of dermis in order of depth
papillary dermis (more superficial)
reticular dermis
embryologic origin of melanocytes
neural crest
I correspond to the alignment collagen and elastic fibers in the reticular dermis
Langer lines
I am the predominant skin cell
keratinocyte
True or false: new skin cells are generated in tissue expansion
True
skin nearby also recruited
Five layers of the epidermis in order of depth
Stratum:
corneum
lucidem
granulosum
spinosum
basale
Epidermal layer that 1) BCC and 2) SCC arises from
1) BCC - stratum basale
2) SCC - stratum spinosum
I sense vibration and deep pressure
Pacinian corpuscle
Melanocytes convert me into melanin
tyrosine
Impact of tissue expansion of thickness of 1) subcutaneous tissue and 2) muscle
subcutaneous tissue and muscle get thinner
Epidermal layer where keratinocytes begin to lose nuclei
stratum granulosum
germ layers that 1) epidermis and 2) dermis arise from
1) epidermis from ectoderm
2) dermis from mesoderm
I connect keratinocytes to each other
desmosomes
I come from bone marrow and present antigens in the skin
Langerhans cell
Impact of tissue expansion on thickness of the 1) epidermis and 2) dermis
1) epidermis thickens
2) dermis thins (lasts for 36 weeks)
Thickest epidermal layer
stratum spinosum
Layer in which friction blisters form
stratum spinosum
I sense light touch and help discrimination and I stain for cytokeratin 20
Merkel cell
True or false: melanin is only found in melanocytes
False, keratinocytes phagocytose processes of melanocytes for melanin
True or false: new hair follicles are made during tissue expansion
False, follicles distract
Epidermal layer (1) thinned and (2) thickened by tretinoin
1) stratum corneum is thinned
2) stratum granulosum is thickened
Five independent functions of the skin
Barrier to trauma
Immunologic defense
Homeostasis
Sensation
Endocrine/Exocrine functions
I make up one third of total body protein content
collagen
I make collagen and elastin
fibroblast
stimulus for angiogenesis in expanding tissue
ischemia