Eye Anatomy Flashcards
What is the name of the structure that supports the eyelid?
The Tarsal Plate.
it is a fibrous tissue which gives shape and strength the the eyelid and provides a place for the elevator palpebrae to attach.
What are the muscle which are responsible for the movement of the eye lid and what nerves supply these muscles?
Orbicularis Oculi closes lid - CN VII
Lavator Palpbrae opens the eye - CN III
Which structure lies underneith the tarsal plate and secreted and oil onto the eye?
The meibomian glands. The oil stops the tears evaporating too quickly.
At what point does the cornea stop at the front of the eye and what is this point called?
Stops at the edge of the cornea and is called the limbus
Where are the majority of the tears produced and what is the name of the other gland responsible for tearing?
Most is the accessory tear gland, the rest is the lacrimal gland but this is only responsible fore reflexive tearing
Where do tears drain to and what path do they follow?
drain out lacrimal puncta, down the lacrimal tubing and then into the inferior turbinate of the nose
What are the three chambers of the eye and where are the boundaries?
Anterior Chamber - Cornea to iris
Posterior Chamber - iris to lens
Vitreous Chamber - Lens to retina
Where is the anterior chamber angle and what structures are associated with it?
The angle between the cornea and the iris. The trabecular meshwork is here and this is on top of the canal of Schlemm
What is the uvea?
The uvea is the collective term for the iris, ciliary body and the choroid as these structures are continuous (think about it)
What are the two functions of the ciliary body?
controlling the shape of the iris and screwing aqueous fluid
What structure tethers the lens to the ciliary body?
the zonular fibres
What is the function of the choroid in the eye?
Blood vessels which supply the outer third of the eye. Supply the cones and rods of the retina
What are the three laters of the lens?
The capsule, the cortex and the nucleus
How does contraction of the ciliary body affect the shape of the lens?
Contraction of the ciliary body causes the lens to become more round as this allows the zonular fibres to relax
With age people become more long sighted and have difficulty seeing things close up. Why is this and what is it called?
Because the lens gets harder with age the lens becomes less complient and so when the ciliary body contracts the lens stays long instead of round. This is called presbyopia
