Choroid Flashcards
what kind of capillaries are the choroid capillaries?
fenestrated capillaries
what is the tissue type of the choroid
connective vascular tissue (thin)
waht is the function of the choroid
nourishment of the retina and structures around the retina (main), conduit to other parts of the eye (massive movement of water molec), light absorption (bc of melanin pigment)
what is the inner surface of the choroid? outer surface?
inner=part of bruch’s membrane
outer=suprachoroid
what are the limits of the choroid
from posterior optic nerve margins and ends anteriorly at the ciliary body
how many micrometers thick posteriorly and anteriorly?
220 post and 100 ant (thins at ora serrata)
what are the layers of the choroid starting from inner to outer?
bruchs, choriocapillaris, sattlers layer, hallers layer, suprachroid, lamina fusca
which layer contains small and medium vessels?
sattlers layer
which layer contains large vessels?
hallers layer
what is the most outer portion of the suprachoroid before going into the sclera?
lamina fusca
what is the suprachoroidal space?
the area where outer choroid ends and sclera inner begins.
-continous w/ anterior supraciliary space in anterior eye-between ciliary stroma and trasition to sclear anteriorly
what are the cells in the suprachoroid
melaoncytes and fibroblasts
the stroma contains which layers?
what cells are in the stroma?
both vascular layers (hallers and sattlers)
- random collagen 1, elastic fibers, fibroblasts, melanocytes
- also, mast cells, macrophages, lymphocytes
what are the vascular layers (outer hallers and sattlers layer) supplied from?
short posterior ciliary arteries
in the vascular layers, the venous drainage is from the
vortex veins (4-6)
- each drain 1 sector of choroid
- drain into sup and inf. ophthalmic veins after pierce sclera
what supply the posterior part of the choroid? what supply the anterior choroid?
short post ciliary artiers
anterior cil and long post cil supply anterior
what is the choriocapillaris?
bed of fenestrated capillaries. it is a vascular network fed from sattlers layer
what is the choriocapillaris separated from?
RPE by Bruch’s
the choroid does ______ by blood flow, it can change its blood flow as needed
thermoregulation
blood flow regulation can affect
IOP-cna change blood flow to increase or decrease IOP
-protection of sclera from increases in IOP
choroid has a role in ocular growth regulation:
-large changes in ____ in response to defocus in animal models
thickness
-also in humans but must smaller changes
changes in choroidal thickness also form part of the _____ response to defocus.
how do they change for myopes? hyperopes?
compensatory.
thicken in myope
thin in hyperopic defocus
