Uvea - Week 2 Flashcards
Where does the choroid begin?
Where the ciliary body ends
What is the function of ciliary body?
To produce aqueous, which provides nutrition
What is the pars plicata?
It surrounds the ciliary processes, responsible for aqueous humour production
What do the pars plicata attach to?
To the lens via zonules
What is the pars plana, and what does it merge with?What is the border of mergence called?
Connects to the pars plicata inward, and merges with the retina. The border of the pars plana and retina is called the ora serrata
What is the ora serrata?
The border of the pars plana and retina
How does the ciliary body appear on gonioscopy?
You can only see the anterior face of the ciliary body. It appears as a thin line
What is the favoured site for surgical injection to the eye, and why?
Ora serrata, as it’s least likely to be injured
Describe the ciliary process epithelium
It is double-layered. In contact with the aqueous humour
Is the inner epithelium of the ciliary processes pigmented?
No, only the outer epithelium is
Name the 3 zones of the ciliary body
- ciliary epithelium
- ciliary stroma
- ciliary muscle
Where is the newly made aqueous humour released, and where does it go?
Released into the posterior chamber, and travels up, around the lens, and through the pupil, into the anterior chamber
What is the inner (non-pigmented) layer of the epithelium of ciliary processes continuous with?
Neural retina
What is the outer (pigmented) layer of the epithelium of ciliary processes continuous with?
RPE and Iris
What surrounds the outer epithelium of the ciliary processes?
The inner non-pigmented layer. Inner surrounds outer. Inner is non-pigmented, outer is pigmented
What does the ciliary stroma border?
The ciliary muscle
What covers the ciliary stroma?
Ciliary epithelium layers
Is the ciliary stroma vascular or avascular?
Richly vascularised
Are pigmented cells present in the ciliary stroma?
Yes. Melanocytes
Are fibroblasts present in the ciliary stroma?
Yes
What immune cells can be found in the ciliary stroma?
Mast cells, macrophages and lymphocytes
Name the 3 ciliary muscles beginning with the most superficial. Which has the main bulk?
Longitudinal - form main bulk
Oblique
Circular
Which of the ciliary muscles runs parallel with the sclera?
Longitudinal fibres
During accommodation, which surface of the lens changes more, anterior or posterior?
Anterior
What happens to lens with age?
Thickens
What happens when you accommodate?
Ciliary muscles contract, which loosen the zonules, and allow the lens to increase in curvature.
(Whereas when relaxed, zonules tighten and pull the lens)
Do ciliary muscles receive mainly sympathetic or parasympathetic innervation?
Parasympathetic system (sympathetic is only 1-2%)
Describe the parasympathetic innervation to the ciliary muscles
Receptor: muscarinic receptors To - the midbrain via - ciliary ganglion Nerve - short posterior ciliary nerves Cranial nerve - III (inferior division)
What vessels supply blood to the ciliary body?
Long posterior ciliary arteries (main source) and Anterior ciliary arteries
How do anterior ciliary arteries reach the ciliary bodies? What about the long posterior ciliary arteries?
They travel via the extraocular muscles.
Long posterior ciliary arteries travel between the sclera and the choroid
What do the anterior ciliary arteries and long posterior ciliary arteries form?
Major Arterial Circle
