Skin histology Flashcards
what are the 4 layers of the epidermis
stratum basale
stratum spinosum
stratum granulosum
stratum corneum
function of stratum basale
proliferates and provides cells for the surface
how is the stratum basale attached to the basement membrane
tonofibrils are inserted into hemi-desmosomes of the BM
what do the cells of the stratum spinosum look like
polyhedral-shaped keratinocytes with round-oval nuclei, prominent nucleoli and cytoplasm
function of stratum spinosum
synthesise cytokeratins which accumulate in aggregates = tonofibrils
function of stratum granulosum
has kertaohyaline granules that combine with tonofibrils to produce keratin
what do the cells of the stratum granulosum look like
flattened interconnected keratin squames with no nucleus or cytoplasm
what are the structures called that make up the dermis-epidermis border
epidermal rete ridge
dermal papilla
where are melanocytes found
basal layer of the epidermis
“look” of melanocytes
look like they have a clear area around the nucleus
- have projections up to the surface layer
skin colour is determined by
- melanin content (genetic, sun exposure)
- blood flow
where are langerhans cells found
in the epidermis
function of langerhans cells
APC of the epidermis (modified macrophages)
where are hair follicles found
in the dermis, and sometimes in the subcutaneous layer
where are sebaceous glands found
dermis
what do sebaceous glands look like
foamy looking
where are sweat glands found
normally found in the deep dermis but sometimes in the subcutaneous fat
histology of a sweat gland
2 layers:
- secretory = columnar/cuboidal
- basal = myoepithelial
what is the difference in “look” between the sweat gland and sweat duct of the skin
duct looks darker
what are the 2 main layers of the dermis
superficial layer = papillary dermis (fine collagen bundles)
deeper layer = reticular dermis (coarser collagen bundles)
two main plexuses of the skin
cutaneous plexus
papillary plexus
functions of skin
protection sensation thermoregulation metabolism immunologic sexual attractant
what is the difference in the skin of the scalp
- many more hair follicles (extend into the hypodermis)
what is the difference in the skin of the soles of the feet
epidermis and keratin layers are much thicker
no hair follicles
sweat glands
where do nails attach do
the periosteum of the distal phalanx
what are the features of the skin of the vulva
majora - hair follicles and apocrine sweat glands
minora - no hair follicles, still keratinized, small bundles of muscle, sebaceous and aprocrine glands
what are the 3 main factors influencing the healing of burns
burn depth
surface area
location
