Ciliary Body anatomy and physiology

Question 1

outer to the ciliary body is

Answer 1

Sclera

Question 2

Inner to the ciliary body are

Answer 2

The posterior and vitreous chambers

Question 3

Anterior to the ciliary body

Answer 3

Continuous with the iris, TM, and SS

Question 4

Posteriorly, continuous with

Answer 4

The choroid and retina.

Question 5

Transition between the ciliary body and retina/choroid

Answer 5

Ora serrata

Question 6

Location of pars plicate and pars plana

Answer 6

Pars plicata- wider anterior region.

Pars plana- Thinner, flatter posterior region.

Question 7

Where are ciliary processes located?

Answer 7

Para plicata- wider anterior region.

70-80 processes.

Question 8

What are ciliary processes composed of?
Where do they extend into?
What do they produce?

Answer 8

Composed of projections of ciliary stroma covered by pigmented and non pigmented epithelium.

Extends into the posterior chamber.

Produces aqueous humor.

Question 9

Flow of aqueous humor

Answer 9

From the ciliary processes located in pars plicata.

Into the posterior chamber, between the lens and the iris, though the pupil, into the anterior chamber.

Question 10

Where does pars plana extend from and to

Answer 10

From the posterior pars plicata to ora serrata.

Question 11

What part of the ciliary body appears serrated

Answer 11

Pars plana in the area of ora serrata.

Question 12

Layers of the ciliary body from outer to inner

Answer 12

Outer 
Superciliaris 
Muscles 
Stroma 
Pigmented 
Non pigmented 
Inner

Question 13

Supraciliaris. What is it? What is it continuous with?

Answer 13

Potential space between ciliary body and sclera. Continuous with the surachoroid space (between choroid and sclera)

Question 14

Ciliary muscle. Composed of what?

Surrounded by what?

Answer 14

Smooth muscle fibers with longitudinal, radial, and circular orientations.

Surrounded by the ciliary stroma.

Question 15

Longitudinal muscle fibers attach to

Answer 15

The SS and TM

Question 16

Ciliary stroma is composed of what?

Answer 16

Vascularized, loose CT (collagen, fibroblasts, ground substance) with melanocytes and WBCs.

Question 17

Pigmented epithelium

• How many layers?
• What junctions?

Answer 17

Single layer of epithelial cells that are apex to apex with the non pigmented epithelium.

Gap junctions.

Question 18

Non pigmented epithelium

Answer 18

Most inner layer that lines the posterior chamber and part of the vitreous chamber.

Single layer of epithelial cells joined by tight junctions that form a complete barrier.

Zonules arise from the BM of non pigmented epithelium, which faces the posterior chamber.

Question 19

Where do zonules arise from?

Answer 19

Arise from the basement membrane of these cells. Insert into the lens capsule in the equatorial regions of the lens.

Question 20

Blood supply to the ciliary body

Answer 20

The major arterial circle of the iris (MACI).

Supplies the ciliary body.

Question 21

Capillaries are in the ciliary stroma. Are they fenestrated or non?

Answer 21

They are highly fenestrated. Allow water, molecules, and ions to leak out of the capillaries and enter the stroma.

Question 22

Innervation to the ciliary body

Answer 22

Parasympathetic.

Question 23

How is aqueous humor made?

Answer 23

It is a filtrate of blood.

Question 24

What does aqueous humor consist of?

Answer 24

Water, molecules, and ions that leak out from the capillaries in the ciliary stroma.

Question 25

What force makes the IOP?

Answer 25

Aqueous humor exerts a force on the internal surface area of the anterior eye.

Question 26

2 routes of aqueous humor drainage

Answer 26

1. Trabecular (70-90%)

2. Uveoscleral (10-30%)

Question 27

Trabecular route of aqueous drainage

Answer 27

Anterior chamber
Posterior trabecular meshwork
Schlemms canal 
Aqueous veins to episcleral veins 
OR 
intrascleral collector channels to intrascleral venous plexus to conj/episcleral veins.

Question 28

Uveoscleral route of aqueous drainage

Answer 28

Anterior chamber
Iris root 
Ciliary body 
Supraciliaris 
Suprachoroidal space 
Vortex veins or absorbed into scleral stroma.