Things that were highlighted in NAVDF notes Flashcards
What are the components of the extracellular lipid bilayer?
1) Ceramides
2) Free fatty acids
3) Cholesterol
In which layer of the epidermis are tight junctions found?
SG2 only!
Which layer of the epidermis provides a permeability barrier?
SG2, where tight junctions live
What cell is able to BYPASS tight junctions?
Langerhans cells – dendrites can pass, in order to sample superficial AGs
What is the rate limiting step for collagen synthesis
Prolyl hydroxylase
How does hyperbaric oxygen affect the dermis?
Promotes collagen formation (prolyl hydroxylase)
How does vitamin C affect the dermis?
Promotes collagen formation (prolyl hydroxylase)
What element is needed for lysyl hydroxylase oxidation?
Copper
What are the signals that induce anagen?
WNT, SHH, KGF, noggin (BMP antagonist)
What are the signals that inhibit anagen?
BMP
Signals that induce catagen
TGF-alpha
EGF
FGF-5
BMP
Signal that promotes hair shaft and IRS differentiation
BMP
(helps keep the epidermis between the follicles WNL)
How does noggin induce anagen?
Acts on Lef-1 transcription factor
Which species’ hair is nonmedullated?
Sphinx, sheep wool, angra goats
First hairs to develop
Sinus hairs
Location of tylotrich hairs on body
Scattered throughout, surrounded by neurovascular tissue
Which hairs have epitrichial sweat glands?
Primary only
Which section of hair follicle is shared in compound hairs?
Infundibulum
Which phase of the hair cycle is the bulb present in?
Anagen
Where does arrector pili muscle attach?
Bulge
Inner root sheath only present during this hair cycle phase
anagen and catagen
Which direction does IRS keratinize?
Outside in (henle first)
Mode of secretion of epitrichial sweat glands
MEROCRINE (not apocrine)
-Secretion via exocytosis
Which species do NOT have epitrichial sweat glands?
Rodents, ferrets