Structure and Function Flashcards
what are the two layers of the skin
epidermis and dermis
what cells make up the epidermis
stratified squamous cells
where is the epidermis derived from
the ectoderm
what cells make up 95% of the epidermis
keratinocytes
what are the four defined layers of the epidermis
keratin
granular
prickle cell
basal
what is the dermis derived from
the mesoderm
What are the 4 types of epidermal cell
keratinocytes
melanocytes
Langerhans cells
Merkel’s cells
what are melanocytes and where do they originate from
pigment producing cells originating from the neural crest
what 3 layers are formed at 4 weeks of foetal skin development
Periderm
Basal layer
Dermis
by 16 weeks what are the 5 layers of skin formed
keratin layer granular layer prickle cell layer basal layer dermis
at how many weeks do hair, melanocytes and appendages form
26 weeks
what pattern does the development of skin follow
Blashko’s lines
what factors regulate epidermal turn over
growth factors
cell death
hormones
(loss of this control is seen in skin cancer and psoriasis)
How many days does it take for the epidermis to regenerate (from bottom to top)
28 days
which layer is one cell thick, has small cuboidal shaped cells, contains intermediate filaments and is highly metabolically active
basal layer
the prickle cell layer is thinner in psoriasis true/false
false
its thicker
what layer contains island bodies (secretory cells)
granular