Ciliary Body

Question 1

What is the ciliary body continuous with?

Answer 1

Iris

Question 2

What are the 2 portions of the ciliary body?
Which is anterior? Posterior?

Answer 2

Pars plicata (anterior 1/3)
Pars plana (posterior 2/3)

Question 3

Describe the structure of the pars plicata? What does it contain?

Answer 3

Anterior 1/3 of ciliary body
Contains ciliary process that produces aqueous
Not smooth, plicated

Question 4

Describe the structure of the pars plana? Where does it extend to?

Answer 4

Posterior 2/3 of ciliary body
Extends back to ora serrata of retina

Question 5

What are the 4 functions of the ciliary body?

Answer 5

Accommodation
Aqueous production
Zonule production
Vitreous production

Question 6

On what side are dentate processes more obvious?

Answer 6

Nasal is more obvious compared to temporal side

Question 7

Which portion of the ciliary body is best in inject needle into? Why is this?

Answer 7

Pars plana
Has lower blood supply

Question 8

How far is the pars plana behind the limbus? Does this vary?

Answer 8

3 to 4mm
Yes, for high myopes and hyperopes

Question 9

Describe the orientation of the apex, anterior, posterior corners, and middle of the ciliary body.

Answer 9

Triangular base is more anterior
Anterior corner at scleral spur
Middle is at iris root
Posterior is next to posterior chamber
Apex at ora serrata

Question 10

What region will the lens be placed if an issue occurs during cataract surgery?

Answer 10

Ciliary sulcus

Question 11

Where do the zonules attach to? How do they aid in accommodation?

Answer 11

Attach to pars plana and lens
Hold lens in place and provide tension based on ciliary body to aid in accommodation

Question 12

What are the 4 layers of the ciliary body from outer to inner?

Answer 12

Supraciliaris
Ciliary Muscle
Ciliary Stroma
Two layers of epithelium

Question 13

What are the functions of collagen bands in the supraciliaris? What other 2 structures are located in the supraciliaris?

Answer 13

Collagen bands allows CB to slide and move
Fibroblasts and pigmented melanocytes
Fluid under abnormal conditions

Question 14

What is on the posterior side of the supraciliary space?

Answer 14

Lamina fusca (sclera)

Question 15

What are the 3 ciliary muscles?

Answer 15

Longitudinal muscle
Radial muscle
Circular muscle

Question 16

Describe the 2 layers of epithelium. Which is outer/inner, which is pigmented/non pigmented? What are each continuous with?

Answer 16

Pigmented ciliary epithelium (outer)- continuous with anterior iris epithelium

Nonpigmented ciliary epithelium (inner)- continuous with posterior iris epithelium

Question 17

What is the orientation of the two layers of the CB epithelium?

Answer 17

Apex to Apex

Question 18

Describe ciliary body detachment (effusion).

Answer 18

Separation of ciliary body and sclera in supraciliaris space, cause when pressure gets low, fluid enters.

Question 19

What is the sensory innervation to the ciliary body from?

Answer 19

Nasociliary branch of V

Question 20

What is the pathway of sympathetic innervation in the ciliary body?

Answer 20

Superior cervical ganglion
LPCN
Blood vessels (to control tonus)

Question 21

What is the pathway of parasympathetic innervation in the ciliary body?

Answer 21

Ciliary ganglion
SPCN
Ciliary muscle (accommodation)

Question 22

Describe the vascular supply to the CB.

Answer 22

Major Circle of Iris- Branches go posterior to CB
Venous return mostly through vortex veins
Terminate at fenestrated capillaries

Question 23

What happens to the non pigmented epithelium at the ora serrata?

Answer 23

Becomes multi layered

Question 24

Describe orientation the longitudinal ciliary muscle.

Answer 24

Adjacent to the supraciliaris
Parallel to the sclera
Long narrow “V”- apex in choroid, base at spur

Question 25

Where does the origin and insertion of the longitudinal ciliary muscle occur?

Answer 25

Tendon of origin inserts into spur and TM
Insertion into choroid via stellate-shaped terminations or “muscle stars.”

Question 26

Describe orientation the radial ciliary muscle.

Answer 26

Beneath (deep) the longitudinal muscle
Wider, shorter interdigitating “Vs”
Transition to circular fibers
Outer to ciliary

Question 27

Where does the origin and insertion of the radial ciliary muscle occur?

Answer 27

Origin at spur
Insertion into connective tissue near the base of ciliary processes

Question 28

Describe the orientation of the circular ciliary muscle (muller’s annular muscle).

Answer 28

Innermost
Circular muscle bundle with sphincter-like action

Question 29

Describe the orientation and histology of the ciliary stroma. What does it form? What is it continuous with?

Answer 29

Loose connective tissue lying between the muscle and the epithelial layers
Forms core of the ciliary processes
Continuous with the connective tissue separating muscle bundles

Question 30

What is the ciliary storma continuous with anteriorly and posteriorly?

Answer 30

Anteriorly – continuous with iris stroma
Posteriorly – thins at pars plana and becomes continuous with the choroidal stroma

Question 31

What major circle is located in the stroma?

Answer 31

Major anterior circle is in stroma, anterior to the circular muscle and near the iris root

Question 32

Describe the capillaries within the ciliary stroma. Where are they mainly located?

Answer 32

Large and fenestrated (leaky)
Mainly near the ciliary processes where aqueous is made

Question 33

Describe the outer layer of the ciliary epithelium. Histology, location, continuity, communication?

Answer 33

Next to stroma
Pigmented
Cuboidal
Joined by desmosomes and gap junction
Continuous with anterior iris epithelium and RPE

Question 34

Describe the inner layer of the ciliary epithelium. Histology, location, continuity, communication?

Answer 34

Nonpigmented
Columnar in the pars plana and cuboidal in the pars plicata
Near apices: desmosomes, gap junctions, tight junctions
Blood– Eye Barrier
Continuous with posterior iris epithelium and sensory retina
ACTIVELY secretes aqueous humor