orbit and eye Flashcards
what is the bony orbit?
bilateral, symmetrical cavities containing the eyeballs and associated structures
what bones make up the superior bony orbit?
frontal bones
what bones makes up the medial orbit?
ethmoid bone and the lacrimal bone
what bones make up the deep orbit
sphenoid bone
what bone makes up the lateral orbit
zygomatic bone
what bone makes up the inferior bony orbit
maxilla
what nerves go through the superior orbital fissure
oculomotor nerve, trochlear nerve, ophthalamic division of trigeminal nerve, abducens nerve
what nerves go through the optic canal
optic nerve
what nerves go through the inferior orbital fissure
none!
what are the three lateral layers of the eye
outer fibrous layer, middle vascular layer, inner neural layer
what is in the outer fibrous layer of the eye?
sclera and cornea
what is in the middle vascular layer of the eye
iris, ciliary body, and choroid
what is in the inner neural layer
retina
what is the function of the cornea
to firstly retract the light entering the eye - directing light to the lens
what is the function of the sclera
supportive outer layer, attachment site of extraocular muscles, lubricates eye
what is the function of the limbus
transition zone btw the cornea and sclera
what is the combo of the iris, ciliary body, and choroid called?
uvea
what is the function of the iris
contains pupillary dilator and sphincter muscles to control pupil size
what is the function of the ciliary body?
to produce aqueous humour that nourishes avascular cornea, contains ciliary muscles, and helps focus lens using zonular fibers and ciliary muscles
what is the function of the lens?
to focus light on the retina
what do ciliary muscles, zonule, and lens look like when focusing on distant bjects
ciliary muscles would be relaxed, the zonule would be taut, and the lens would be flattened for focusing on distant objects
what nervous system controls the sphincter pupillae?
the parasympathetic nervous system`
what do the sphincter pupillae do?
contricts pupil when the sphincter pupilae is contracted
are the sphicter pupillae muscles proximal or distal to the pupil?
proximal!
what is the purpose of the choroid?
to nourish the retina and maintain eye temp and volume
what is the purpose of the retina
captures light to send to the brain
what is the the outer fibrous layer
sclera and the cornea
what is in the middle vascular layer
iris, choroid, ciliary body
what is in the inner layer
retina
what chambers are in the anterior cavity of the eye
anterior and posterior chamber
what chamber is in the posterior cavity of the eye
vitreous chamber
where is the anterior chamber
btw cornea and the iris`
what is the purpose of the anterior chamber
to contain the aqueus humour
where is the posterior chamber
btw the iris and the lens
what is the purpose of the posterior chamber?
to aid in production and circulation of aqueous humour
what is the purpose of aqueous humour?
to main eye pressure
what is the purpose of the vitreous chamber?
to contain vitreous humour
what is the purpose of vitreous humour
to maintain shape of eye, to nourish the eye
where is the vitreous chamber of the eye
behind the lens
which extraocular muscles are on top of the eye?
superior rectus, trochlea, superior oblique
what extraocular muscles are on the lateral and medial sides of the eye
the lateral rectus and the medial rectus
what extraocular muscles are on the bottom of the eye?
inferiror oblique and inferior rectus
what movement does the inferior oblique do?
moves the eyeball up and out
what movement does the superior oblique do?
moves the eye down and out
what movement does the superior rectus do?
moves eye up
what movement does the lateral rectus do?
moves eye laterally
what innervates the extraocular muscles?
the oculomotor nerve except it does not innervate the lateral rectus (this is the abducens nerve) and the superior oblique (this is the trochlear nerve)
what is the lacrimal apparatus
system of glands and ducts that produces and drains lacrimal fluid
what is lacrimal fluid?
fluid that lubricates eye surface, removes debris from eye, aka tears
where is the lacrimal gland on the eye?
superior and lateral
what structures does the lacrimal apparatus contain?
lacrimal gland, excretory lacrimal ducts, superior and inferior puncta, superior and inferior lacrimal canaliculi, lacrimal sac, and nasolacrimal duct
(LNL PEC)
what structures of the lacrimal apparatus are medial?
puncta, canaliculi, lacrimal sac, nasolacrimal duct
