Anatomy of the Ciliary Body

What's the functions of the ciliary body?

- Accommodation - Aq production by the nonpigmented ciliary epithelial cells which sit inner against the posterior chamber - zonule production - vitreous production

Why's the pars plicata rough?

Bc of ciliary processes

Where is the major circle of the iris?

In the ciliary stroma; not in the iris.

Go outside in from sclera:

Sclera -> ciliary body -> iris

What's the ora serrata?

The most anterior part of the retina. This is where the retina and ciliary body (pars plana of the ciliary body) are continuous with the retina.

How does the ora serrata of the retina and the ciliary body come together?

The ora serrata of the retina has dentate processes and the ciliary body (pars plana part) has oral bays which the dentate processes of the ora serrata part of the retina indent into.

Where in the ciliary body would you do an injection?

The pars plana bc it's less vascularized than pars plicata.

What does the circular ciliary muscle do?

When the circular ciiliary muscle contracts (inner most layer of the ciliary mucle) it relaxes the zonules allowing the lens to thicken for acc.

What are the layers of the ciliary body?

-Supraciliaris -Ciliary muscle -Ciliary stroma -2 Layers of epithelium Nonpigmented (inner) Pigmented(outer)

What's the width of the ciliary body?

5.9mm on the nasal side 6.7mm on the temporal side

Anterior base of ciliary body: Middle base of ciliary body: Posterior base of ciliary body: Apex or posterior part of ciliary body:

Anterior base of ciliary body: against scleral spur (posterior of scleral spur is where ciliary muscle fibers start; anterior of scleral spur is where trabecular meshwork is) Middle base of ciliary body: iris root where iris inserts into the ciliary body Posterior base of ciliary body: Faces the posterior chamber and vitreous. where zonules come out of? Apex or posterior part of ciliary body: Ora serratus; the most anterior part of the retina which inserts/meets the pars plana's oral bays with dentate processes

What's the most anterior ciliary muscle layer?

Anterior is longitudinal ciliary muscle then radial muscle(which has aspects of both the longitudinal and circular layers) then circular most inner LRC don't be a lurker LRC

How are the 2 layers of the ciliary epithelium arranged?

Apex to apex nonpigmented is inner The iris epithelium which both are pigmented are also organized apex to apex

Is the ciliary body wider on the nasal or temporal side?

Ciliary body is wider on the temporal side bc the retina and ciliary body are continuous so retina is wider on the nasal side how it comes into the eye so the ciliary body is less wide on the nasal side

Compare the capillaries in the iris stroma and ciliary stroma:

Iris stroma = Nonfennestrated capillaries; most anterior part of the blood eye barrier Ciliary stroma = fennestrated esp near the ciliary processes so blood can flow out, through ultrafiltration move into pigemented ciliary epithelium then nonpigmented epithelium, Na K, HCO3, and Cl out and water in, aq is prod via an active process.

Is this iris stroma or ciliary stroma thicker?

Iris stroma is thicker. Ciliary body is mostly muscle.

Describe the longitudinal ciliary muscle

Longitudinal ciliary muscle is adjacent to the supraciliaris and runs parallel to the sclera.

Where does the longitudinal muscle start and end? What happens when it contracts?

Longitudinal muscle makes a long narrow V shape inserting into the posterior part of the scleral spur which has its anterior attachment in the TB. The longitudinal ciliary muscle ends at the choroid via muscle stars. When it contracts in an anteroposterior motion (moves backwards) it will pull on scleral spur and TB increasing outflow

What's the ciliary body mostly composed of?

Muscle

How much of the ciliary body is the pars plana?

Pars plana is the posterior 2/3 of the ciliary body

How much of the ciliary body is the pars plicata?

Pars plicata (rough) is the anterior 1/3 of the ciliary body

Is the pars plicata or pars plana wider?

Pars plicata.

What part of the ciliary body is up against the lamina fusca?

The lamina fusca is the innermost layer of the sclera. The supraciliaris layer of the ciliary body is up against the lamina fusca bc it's the most anterior/outer part of the ciliary body. The supraciliaris has collagen that allows it to slide against the sclera when the longitudinal ciliary muscle contracts.

Does the pars plana or pars plicata get more blood supply?

The pars plana is almost nonvascular. But the pars plicata is highly vascular (7% of total ocular blood going to ciliary body) via branches from the major circle of the iris to make aqeuous. The ciliary body can withstand a 75% decrase in blood supply