Ciliary Body Flashcards
What is the ciliary body in general?
Ring like structure behind the iris and surrounding the crystalline lens
What are the two regions of the ciliary body?
- pars plicata
- pars plana
Describe the pars plicata location and what it contains
- wider, anterior portion
- contains ciliary processes that extend into the posterior chamber, space between the processes is called valleys of Kuhn
What are the valleys of kuhnt?
Regions between the ciliary processes
Where is the pars plana?
- it is the flatter region
- extends from posterior of the pars plicata to the ora serrata
What are the dentate processes of the ora serrata? What are oral bays?
- dentate processes are forward pointing spices of the ora serrata (serrated pattern). They are elongation of retinal tissue that expand into the pars plana
- oral bays are the regions between the dentate processes
What are zonule fibers? How do they attach? What do they assist in?
- fibers attach the ciliary body and the lens
- some insert into internal limiting membrane of pars plana and travel through valleys of kuhnt of plicata.
- some attach directly to valleys
- assist in lens change in accommodation
What are the layers of the ciliary body from superficial to deep?
- Supraciliaris
- Ciliary muscle
- Ciliary stroma
- Ciliary epithelium
What kind of tissue/ cells is supraciliaris?
- loose connective tissue
- pigmented melanocytes, fibroblasts, and collagen bands
What is the advantage of the arrangement od the supraciliaris? Disadvantage?
Advantage: allows ciliary body to slide against the sclera without detachment from or stretching the tissue
Disadvantage: allows for the accumulation of fluid within its spaces which could lead to displacement
What kind of muscle is the ciliary muscle?
Smooth
What are the three directions the ciliary muscle fibers are arranged?
Longitudinal, radial, circular
Where does the longitudinal muscle lie?
-adjacent to supraciliaris, parallel to sclera
What is the shape of the longitudinal muscle bundles?
- long narrow V
- base is at the scleral spur
- apex is in the choroid
Where is the longitudinal ciliary muscle insertion?
-in anterior 1/3 of choroid (muscle stars)
Describe the radial ciliary muscle fibers
- wider, shorter Vs
- originate at scleral spur and insert into connective tissue near the base of the ciliary processes
Describe circular muscle
- innermost region
- circular bundles with sphincter action
- located near the major circle of the iris
Describe the innervation of the ciliary muscle
- para: activates muscle for contraction
- sym: inhibitory effect
What type of tissue is the ciliary stroma?
-highly vascularized loose connective tissue
Where is the ciliary stroma located? What does it form?
-located between ciliary muscle and epithelial layers and forms the core of each ciliary process
What is the ciliary stroma continuous with anteriorly? Posteriorly?
- Anteriorly: continuous with iris stroma
- Posteriorly: thins in the pars plana is continues as choroidal stroma
Where is the major arterial circle of the iris located?
-in ciliary stroma anterior to the circular muscle and near the iris root
What forms the major arterial circle of the iris?
-anastomoses of the long posterior ciliary arteries and the anterior ciliary arteries
Where are the ciliary stromal capillaries located?
- near the pigmented epithelium
- they are large and fenestrated, especially in ciliary processes
