DERM WEEK 1 Flashcards
Which component of skin?
- outer layer
- stratified cellular epithelium
- contain keratinocytes (structural keratins)
- recieves movement from basement membrane
- contains four layers
epidermis
Which component of the skin?
- formed from mesoderm below ectoderm
- beneath epidermis
- made up of connective tissue
- less cellular
dermis
what cells produce pigment in the skin?
melanocytes
- from neural crest (transient embryonic structure that gives rise to most of the peripheral nervous system)
what three layers are formed at 4 weeks of foetal skin development?
- periderm
- basal layer
- dermis

what five layers are produced at 16 weeks? (final stage development)
- (from inner to outer)
- dermis
- basal layer
- prickle cell layer
- granular layer
- keratin layer

where are melanocytes loacted?
- in the basal layer
what are blaschko’s lines?
- development growth pattern of skin
- lines become apparent when some diseases of skin or mucosa maifest themselves into these patterns

what five layers does the skin consist of?
- epideris
- appendages (nails, hair, glands, mucosae)
- dermo-epidermal junction
- dermis
- sub-cutis
what is the sub-cutis?
predominantly fat
name three key cells in the epidermis
- melanocytes
- langerhans cells
- merkel cells
name three body sites where the epidermis may vary
- scalp
- armpit
- sole of foot
skin on palm

abdominal skin

scalp skin

what three factors control epidermal turnover?
- growth factors
- cell death
- hormones
how many days does it take for the epidermis to regenerate?
28 days
where do keratinocytes migrate from?
basement membrane
purpose of keratinocytes?
- preserve agains microbial, viral, fungal and parasitic invasion
- protect against UV radiation
- minimise heat, solute and water loss
what layer of the epidermis?
- usually one cell thick
- small cuboidal
- lots of intermediate filaments (keratin)
- highly metabolically active

basal layer
what epidermis layer?
- large polyhedral cells
- lots of desmosomes (connections)
- intermediate filaments connect to the desmosomes

prickle cell layer

what layer of the epidermis?
- 2-3 layers of flatter cells
- large keratohyalin granules
- contain filaggrin and involucrin
- lamellar bodies
- high lipid content
- cell nuceli and organelles lost

granular layer

what layer in the epidermis?
- overlapping non-nucleated cell remnants
- insoluble cornified envelope
- 80% keratin and filarggrin
- lamellar granules release lipid
- acts as a tight waterproof barrier

keratin layer

purpose of the teeth being keratinised?
to deal wtih friction/pressure
name some organs that are lined by mucosal membrane
- eyes
- mouth
- nose
- genito-urinary
- Gi tracts





























