Ciliary Body

Question 1

what is the main function of the ciliary body

Answer 1

to form and secrete aqueous humor and enhance the outflow

Question 2

what functions of the ciliary body have been suggested

Answer 2

it may be involved in synthesizing lens zonules and hyaluronic acid of the vitreous humor

Question 3

where in the uvea is the ciliary body

Answer 3

intermediate portion

Question 4

which side of the eye (temporal or nasal) is the ciliary body longer

Answer 4

temporally by 1mm

Question 5

what is the supraciliary lamina

Answer 5

where there are loose attachments from the outer surface of the ciliary body and the lamina fusca (sclera)

Question 6

where is the supraciliary space

Answer 6

between the supraciliary lamina and the lamina fusca

Question 7

what is the pas plicata

Answer 7

begins at the iris root and has fin-like projections/ridges that go into the posterior chamber

Question 8

what is a ciliary process

Answer 8

the fin-like projection from the pars plicata

Question 9

where is the aqueous humor secreted

Answer 9

from the ciliary processes

Question 10

how many ciliary processes are there per eye

Answer 10

about 70-80

Question 11

what travels between the ciliary processes

Answer 11

the lens zonules from the lens

Question 12

what is the pars plana

Answer 12

the posterior continuation of the ciliary body from the pars plicata

Question 13

what is at the nasal edge of the pars plana

Answer 13

the scallopes of the ora serrata (the temporal side is straight)

Question 14

what is the central bay/ora bay

Answer 14

the scallopes of the ora serrata

Question 15

what are dentate processes

Answer 15

retinal teeth in between the ora bays

Question 16

where is the ciliary sulcus

Answer 16

posterior to the root of the iris

Question 17

what is the ciliary sulcus used for

Answer 17

placement of haptics from IOL’s when they cannot be placed in the capsular bag

Question 18

does the ciliary body have a bilayered epithelium

Answer 18

yes- nonpigmented and pigmented ciliary epithelium

Question 19

which direction does the base of the nonpigmented epithelium face

Answer 19

the posterior chamber

Question 20

what connects the PE and NPE

Answer 20

junctional complexes that keep the potential space between them from separating and gap junctions

Question 21

why do the apices of the PE and NPE face each other

Answer 21

they were derived from a single layer during embryological development

Question 22

what does the base of the PE face

Answer 22

the ciliary stroma

Question 23

the NPE is a continuous layer with which layers

Answer 23

the posterior pigmented iris epithelium turns into the NPE and that turns into the retina

Question 24

how are the NPE cells joined

Answer 24

tight junctions at the apex and desmosomes at the base

Question 25

why do the NPE cells have tight junctions

Answer 25

to form the blood-aqueous barrier for the ciliary body

Question 26

what is the primary component of the blood aqueous barrier

Answer 26

the zonula occudens (tight junctions)

Question 27

why do the NPE and PE have gap junctions

Answer 27

to work in metabolic concert and work in tandem to create the aqueous humor

Question 28

what shape or the PE cells

Answer 28

cuboidal

Question 29

what is the PE layer continuous with

Answer 29

the anterior pigmented iris epithelium turns into the PE and then it is the RPE

Question 30

do the PE cells have tight junctions

Answer 30

no, they are not part of the blood aqueous barrier

Question 31

how is the ciliary stroma classified

Answer 31

it is loose areolar connective tissue and continuous with the iris stroma

Question 32

why does the ciliary stroma continue into each ciliary process in the pars plicata

Answer 32

to carry the vascular supply that gives rise to the fenestrated capillaries that leak source material to make/secrete aqueous humor

Question 33

what does the major arterial circle (MAC) supply to each ciliary process

Answer 33

an anterior and posterior arteriole

Question 34

is the anterior arteriole fenestrated

Answer 34

yes, it is larger than the posterior and supplies the tip of the process (fenestrated for the formation of aqueous humor)

Question 35

is the posterior arteriole fenestrated

Answer 35

no, it is the vascular supply to the ciliary muscle

Question 36

what forms the major arterial circle of the iris

Answer 36

branches of the anterior ciliary and long posterior ciliary arteries

Question 37

what is the bulk of the ciliary body

Answer 37

the ciliary muscle

Question 38

what type of muscle is found in the ciliary body

Answer 38

smooth muscle (3 types)

Question 39

what is the outer most muscle of the ciliary muscles

Answer 39

the longitudinal or Brucke's fibers

Question 40

where is the apex of the longitudinal muscle located/where does it originate

Answer 40

from stellate structures called epichoroidal stars that are located in the anterior 1/3 of the choroid

Question 41

where does the longitudinal muscle insert (the base)

Answer 41

in the scleral spur and the trabecular meshwork

Question 42

what happens to the longitudinal muscles during accommodation

Answer 42

contraction pulls on the trabecular meshwork and increases the size of the openings so the aqueous humor can exit the eye more readily (decreasing IOP)

Question 43

where do the radial muscle fibers originate

Answer 43

in the scleral spur

Question 44

where do the radial muscles insert

Answer 44

into connective tissue near the base of the ciliary processes of the pars plicata

Question 45

what are the inner most muscle fibers

Answer 45

the annular or circular muscle fibers

Question 46

where is the circular muscle located

Answer 46

close to the peripheral edge of the lens

Question 47

what is the action of the annular or circular muscles

Answer 47

sphincter like action during accommodation, mostly involved in accommodation