Structure and function of skin Flashcards
what embryological layer forms epidermis
ectoderm - to make periderm
what embryological layer forms dermis
mesoderm
what forms melanocytes
neural crest
what are Blaschko’s lines
pattern of developmental growth of skin cells. it does not follow vessels, nerves or lymphatics
true/false - epidermis is stratified columnar epithelia
false - it is stratified squamous epithelia
what is the primary cell type of the epidermis
keratinocyte
name 2 examples of where control of cell turnover is lost in the epidermis
skin cancer
psoriasis
the basal layer is how many layers thick and is made up of what type of stem cells
1 layer thick
cuboidal stem cells
what intercellular junctions do cells in the prickle cell layer contain
desmosomes
what is the keratin layer made up of
non-nucleated remnants of keratinocytes
keratin
filaggrin
how is the keratin layer waterproof
filaggrin binds water
tight intercellular junctions limit diffusion
intercellular lipid bilayer and lipid content repels water
what do keratohyalin granules contain and where are they found
keratin and filaggrin
granular layer
what do lamellar bodies contain/secrete
lipids and filaggrin
how do melanocytes create colour in the skin?
contain melanosomes that travel up dentrites to release melanin to keratinocytes
what is the compound converted to melanin by melanocytes?
tyrosine
how does melanin protect basal cells
blocks passage of UV radiation from light to basal cells to prevent DNA damage