Chambers of eyeball Flashcards
Pg 176-178
Where is the anterior chamber found?
between iris and cornea
what is the volume of the AQ in the anterior chamber?
0.2ml
What is the depth of the AC in the centre?
3mm
What binds the posterior chamber?
anteriorly: iris
peripherally: ciliary processes
posteriorly lens and zones
communicates with anterior chamber via pupil
what is the rate of formation of the aqueous?
2-6microlitres/minute
describe the drainage of the aqueous
90% trabecular meshwork
10% anterior surface of ciliary body - AQ enters extracellular spaces and diffuses into suprachoroidal space –> vortex veins
What is the function of the aqueous humor>
supply metabolic needs of lens and cornea, supports wall of eyeball and maintains optical shape
what does the aqueous contain?
glucose, amino acids, ascorbic acid, dissolved gasses
what is the normal IOP and what does it vary with?
10-20mmHg
Varies with each heartbeat and respiration
List three things that contribute to maintenance of normal IOP
rate of formation of AQ by ciliary processes
Rate of drainage through TM
pressure in episcleral vessels into which canal of Schlemm drains
How often is the entire volume of aqueous replaced?
every 1-2hrs
What forms the blood-aqueous barrier
zonula occludes of non pigmented ciliary epithelium (NB can become disrupted by inflammation)
where are the two most likely places for resistance to AQ outflow?
where the lens is in contact with the iris (age, diabetes, synechiae)
where the AQ leaves the anterior chamber to enter veins
How do corticosteroids cause an increase in IOP?
They close the AQ outflow channels by altering the acid mucopolysaccharide content of the TM
What is the main source of antioxidants in the anterior chamber?
The ciliary body (contains high levels of superoxide dismutate, glutathione peroxidase, catalase)
