RPE Flashcards
what type of cells are located in the RPE
polarized cuboidal epithelial cells
what are the functions of the RPE
absorption of excess light, blood-retina barrier, eliminate waste, distribute nutrients to retina, processes vitamin A
how many cells are in the RPE
4-6 million in a hexagonal patter
where is the RPE the densest
in the fovea
how many RPE photoreceptors does each cell face
30-40
what is the RPE responsible for, for each photoreceptor
phagocytizing tne shed discs from the outer segments on a daily basis
what is the potential space called between the RPE and photoreceptor
the subretinal space
what extends from the apical surface of the RPE
micovilli
what is between the apical membrane and the photoreceptor layer
the interphotoreceptor matrix (gel substance) and exchanges metabolites
where is the end product of phagocytosis of the discs deposited
either on Bruch’s membrane as Drusen or remain within the cell as Lipofuscin
how often does the whole photoreceptor outer segments get turned over
8-13 days
what makes the RPE cell unique
it has sodium-potassium ATPase pump in the apical membrane
what do the sodium-potassium ATPase pumps regulate
the fluid fluxes that contribute to the adhersion of the neurosensory retina to the RPE
where are zonula occludens located
apically along the lateral membrane, between adjacent RPE cells
what does the basal membrane have
highly convoluted infoldings extending 1mm into the cytoplasm of the cell
