Anatomy of the Eye and Retina Flashcards
what is the site of attachment for the muscles of the eye?
the common tendinous ring (annulus of Zinn)
what are the muscles of the eyelid?
orbicularis oculi
levator palpebrae superioris
superior tarsal muscle
what are the layers of the eyeball?
outer fibrous layer- cornea, sclera, limbus
middle vascular layer- iris, cilliary body, choroid
inner coat- retinal pigment epithelium, retina
where does regeneration of the cornea occur from?
the limbus
what is the function and innervation of the colliery muscle?
innervation- parasympathetic CNIII
function- contracts to pulls cilliary process forward causing the lens to flatten (important for near vision)
what is the function and innervation of the sphincter pupil and dilator pupilae?
sphincter pupillae- contracts pupil, parasympathetic CNIII
dilator pupillae- dilates pupil, sympathetic CNIII
what is the innervation and action of the rectus muscles?
medial- oculomotor CNIII, adduction
lateral- abducens CNVI, abduction
superior- occulomotor CNIII, elevation, adduction and intorsion (of adducted eye)
inferior- occulomotor CNIII, depression, abduction and exotorsion (of adducted eye)
what is the innervation and action of the oblique muscles of the eye?
superior- trochlear CNIV, depression, abduction and intorsion
inferior- oculomotor CNIII, elevation, adduction and extorsion
what is the ophthalmic artery a branch of?
the internal carotid
where does the opthalmic artery enter the orbit?
the optic canal
what does the central retinal artery supply?
central retinal artery- supplies inner retina
which nerve supplies sensation over the cornea?
ophthalmic branch of CNV
where does the lacrimal lake drain?
upper and lower puncta which form openings into the lacrimal canaliculi which lead to the lacrimal sac
where does the lacrimal sac drain?
the lacrimal sac drains into the nasolacrimal duct which drains into the nasal cavity via the inferior nasal meatus
what controls lacrimation?
parasympathetic nervous system
where is aqueous humour produced?
ciliary body
where is aqueous humour found?
the anterior chamber between the lens and the cornea
where does aqueous humour drain?
through the trabecular meshwork into the canal of schlemm
what is open and closed angle glaucoma?
open- outflow of aqueous humour through the trabecular framework is reduced
closed- the iris is forced against the trabecular meshwork preventing any drainage
what does glaucoma cause?
disruption of drainage of aqueous humour leads to increased intraocular pressure which causes damage to the optic nerve
what are the layers of the retina from superficial too deep?
internal limiting membrane nerve fibre layer granular layer inner plexiform layer inner nuclear layer outer plexiform layer photoreceptor layer pigmented epithelium
what is the function of the retinal pigmented epithelium?
contains a high concentration of melanin and it very dark to prevent the reflection of light back into the eye. also provides photoreceptors with vitamin A (essential for phototransduction)
when are on centre off surround retinal ganglion cells activated/inhibited?
the RGC is activated when light hits the centre and inhibited when light hits the surround
what is the function of amacrine cells?
they generate the inhibitory surrounds for the RGCs
