Which wall and bones are commonly fractured?
The medial wall
What is the function of the cornea?
Bends light - refracting it
What is the choroid?
A layer of blood vessels beneath the retina
What happens if you lose the corneal endothelium?
It doesn't come back (those cells don't divide)
Eye swells - v. painful
Which muscle elevates the eyelid?
Levator palpebrae superiosis
How does the entry of the optic nerve appear?
Which arm of the NS innervates sphincter pupillae?
Which muscles control the aperture of the eye?
Spincter papillae: constricts the pupil
Dilator papillae: dilates the pupil
What causes presbyopia?
The lens looses flexibility
Which bones make up the lateral aspect of the orbit?
Greater wing of the sphenoid
What are zonules?
Ligaments that tether the lens to the ciliary processes
Which muscle closes the upper lid?
Describe the course of flow of the aqueous humour
It is produced by the ciliary epithelium
Travels through the pupil
Drain via the anterior chamber angle into the venous system
What layer do extraocular muscles attachment to the eye?
What is the lamina cribosa?
Fibres of the sclera that pass over the optic nerve in a mesh like pattern
What are the names of the ciliary arteries?
Long posterior ciliary artery
Short posterior ciliary artery
Anterior ciliary artery
Which branch of the NS innervates the ciliary muscles?
What are the layers of the cornea?
What is the function of the endothelium of the cornea?
The maintain fluid balance
What are the functions of the ciliary body?
Produce aqueous humour
Tether the lens
House the ciliary muscle
Does the fovea have rods?
Why is the cornea transparent?
Because the collagen is laid out in a very ordered manner
What is the most important role of the ciliary epithelium?
Produce aqueous humour
What is the optic nerve formed by?
Axons of ganglion cells
How can the eyelids be described?
Transition zone between conjunctiva and skin
What does the ciliary muscle do?
Allows focusing via the lens
What happens if the corneal epithelium is damaged?
It heals v. rapidly
Describe the dual blood supply of the retina?
Central retinal artery supplies the inner layer of the retina while the posterior ciliary artery supplies the outer layer of the retina
How are the cornea and sclera arranged in relation with each other?
They are continuous
When the ciliary muscles are contracted, at what distance can you focus?