Skin Structure + Function Flashcards
What is the histology of the epidermis
Stratified squamous epithelium
Name the layers of the epidermis from superficial to deep
- Keratin layer - stratum coreum
- Clear layer - stratum lucidum
- Granular layer - stratum granulosum
- Pricle layer - stratum spinosum
- Basal layer - stratum basale
Merkel cells are found in what layer of the epidermis
basal cell layer
Function of merkel cells
touch receptors
- contain mechanoreceptors
after how many weeks gestation is the skin considered to be fully formed
26 weeks
- basal layer + dermis formed by 4 weeks
- basic skin anatomy formed by 16 weeks
what are blaschko’s lines
lines which show development growth patterns of skin
what is the dermis mainly comprised of
connective tissue
what is the most prominent cell type in the epidermis
keratinocytes
why do cells in basal layer need to be protected by melanin
stem cells reside here
- DNA capped by melanin as this cannot be replaced
in which cell can you find a birbeck granule
langerhans cells
- they look like tennis rackets
name of melanin that is black/brown in colour
eumelanin
- most common type
name of melanin that is red/yellow in colour
pheomelanin
name the 3 stages of hair growth
- anagen - growing
- catagen - involuting
- telogen - resting
where do melanocytes originate from
neural crest
- in ectoderm during embyrogenesis
epidermis arises from which embryological tissue
ectoderm
dermis arises from which embyroglical tissue
mesoderm
which layer of epidermis contains filaggrin and involucrin? what is their function?
Granular layer
- maintain water barrier of the skin
which type of granules will release filaggrin and involucrin
Lamellar granulues in the granular layer
what are corneocytes
cells of the granular layer that are flattened, have lost their nucleus and released contents of lamellar granules (filaggrin and involucrin)
- create 2-3 layers to become the keratin layer
how many days does it take for cells to migrate from the basement membrane to the keratin layer?
28 days
which amino acid is converted to melanin within melanosomes
tyrosine
why do children with PKU often have pale skin
- Process of converting phenylalanine to tyrosine is disrupted
- tyrosine is required to be converted to melanin
- less melanin is produced – pale skin
name 3 different types of glands found in skin
- eccrine
- sebaceous
- apocrine
where are apocrine glands found
axillae and perineum
- androgen dependent
- produce oily fluid responsible for body odour as bacteria decompose it
