Choroid

Question 1

what kind of capillaries are the choroid capillaries?

Answer 1

fenestrated capillaries

Question 2

what is the tissue type of the choroid

Answer 2

connective vascular tissue (thin)

Question 3

waht is the function of the choroid

Answer 3

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)

Question 4

what is the inner surface of the choroid? outer surface?

Answer 4

inner=part of bruch’s membrane

outer=suprachoroid

Question 5

what are the limits of the choroid

Answer 5

from posterior optic nerve margins and ends anteriorly at the ciliary body

Question 6

how many micrometers thick posteriorly and anteriorly?

Answer 6

220 post and 100 ant (thins at ora serrata)

Question 7

what are the layers of the choroid starting from inner to outer?

Answer 7

bruchs, choriocapillaris, sattlers layer, hallers layer, suprachroid, lamina fusca

Question 8

which layer contains small and medium vessels?

Answer 8

sattlers layer

Question 9

which layer contains large vessels?

Answer 9

hallers layer

Question 10

what is the most outer portion of the suprachoroid before going into the sclera?

Answer 10

lamina fusca

Question 11

what is the suprachoroidal space?

Answer 11

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

Question 12

what are the cells in the suprachoroid

Answer 12

melaoncytes and fibroblasts

Question 13

the stroma contains which layers?

what cells are in the stroma?

Answer 13

both vascular layers (hallers and sattlers)

• random collagen 1, elastic fibers, fibroblasts, melanocytes
• also, mast cells, macrophages, lymphocytes

Question 14

what are the vascular layers (outer hallers and sattlers layer) supplied from?

Answer 14

short posterior ciliary arteries

Question 15

in the vascular layers, the venous drainage is from the

Answer 15

vortex veins (4-6)

• each drain 1 sector of choroid
• drain into sup and inf. ophthalmic veins after pierce sclera

Question 16

what supply the posterior part of the choroid? what supply the anterior choroid?

Answer 16

short post ciliary artiers

anterior cil and long post cil supply anterior

Question 17

what is the choriocapillaris?

Answer 17

bed of fenestrated capillaries. it is a vascular network fed from sattlers layer

Question 18

what is the choriocapillaris separated from?

Answer 18

RPE by Bruch’s

Question 19

the choroid does ______ by blood flow, it can change its blood flow as needed

Answer 19

thermoregulation

Question 20

blood flow regulation can affect

Answer 20

IOP-cna change blood flow to increase or decrease IOP

-protection of sclera from increases in IOP

Question 21

choroid has a role in ocular growth regulation:

-large changes in ____ in response to defocus in animal models

Answer 21

thickness

-also in humans but must smaller changes

Question 22

changes in choroidal thickness also form part of the _____ response to defocus.
how do they change for myopes? hyperopes?

Answer 22

compensatory.
thicken in myope
thin in hyperopic defocus