Eye and Eye movements Flashcards
What vessels exit the Optic Canal?
CN II
Opthalmic A.
What structures pass through the Inferior Orbital Fissure?
Maxillary N.
Infraorbital A.
Zygomatic N. (V2)
What bone of the orbit is normally involved in an orbital blowout fracture?
Maxillary B.
What are some consequences of an orbital blowout fracture?
Diplopia (eyes not aligned)
Globe ptosis (eyeball falling through orbit)
Exophthalmos
What is the movement of the eyeball around the AP axis?
Intorsion (medial rotation)
Extorsion (Lateral rotation)
What extra-ocular muscles abduct the eyeball?
Superior Oblique
Inferior Oblique
Lateral Rectus
What extra-ocular muscles adduct the eyeball?
Superior Rectus
Inferior Rectus
Medial Rectus
What extra-ocular muscles are involved in bilateral eyeball depression?
Superior Oblique M.
Inferior Rectus M.
What extra-ocular muscles are involved in bilateral eyeball elevation?
Superior Rectus M.
Inferior Oblique M.
What nerves pass through the common tendinous ring of the orbit?
Superior/Inferior divisions of CN III
Nasociliary N.
Abducens CN VI
Optic CN II
A patient who is unable to look laterally with the L eye but is still able to perform all other ocular movements most likely has what disorder? What muscle is affected?
Abducens CN VI
Lateral Rectus M.
In a patient with CN IV palsy, what muscle is affected? How will the patient compensate?
Superior Oblique M.
Pt will turn head down and away from the affected side
When would a patient complain the most of diplopia if they have trochlear palsy?
When they have downward gaze (reading)
A patient presents with L eye looking down and out, droopy eyelid, and pupil dilation, what cranial nerve has been affected?
Oculomotor N.
Aneurysms of posterior cerebral A., posterior communicating A., and superior cerebellar A. can compress the Oculomotor N, affecting what autonomic division?
Parasympathetic
How does an afferent lesion affect the pupillary light reflex?
Ipsilateral side will not perform a direct response but will still perform a consensual response because motor innervation is still intact
How does an efferent lesion affect the pupillary light reflex?
Ipsilateral side will not have pupillary muscle constriction but the contralateral side will still have a consensual response because afferents are still intact
What comprises the outer covering of the Optic N.?
Meninges, continuous with meninges from the cranium
What vessels are found running within the Optic N.?
Central Retinal V. and A.
What is the conjunctiva that lines the innermost part of the eyelids?
Palpebral conjunctiva
What is the conjunctiva that lines the outermost part of the eyeball?
Bulbar (ocular) conjunctiva
Between what layers of the eye would a subconjunctival hemorrhage collect?
Bulbar conjunctiva and sclera
Complete Ptosis results from destruction of what CN? What muscle is affected?
CN III
Levator Palpebrae Superioris M.
Partial Ptosis results from destruction of what? What muscle is affected?
Postganglionic sympathetic fibers
Tarsal Ms.
Ptosis as a result of Horner’s syndrome is failure of what muscle?
Tarsal M.
How does papilledema present? What is it caused by?
Bulging optic disc
Caused by increased intracranial pressure
What branch of the Opthlamic A. anastamoses with Middle Meningeal A.?
Lacrimal A.
Sphenopalantine A. anastamoses with what arteries in the nasal cavity?
Anterior and Posterior Ethmoidal As.
Occlusion of what terminal artery will result in blindness?
Central Retinal A.
A patient presenting with dilated veins and small hemorrhages in the eye has occlusion of what vessel?
Central Retinal V.
A patient presenting with a pale retina and a red spot in the eye most likely has occlusion of what vessel?
Central Retinal A.
Where is the lacrimal gland located?
Lateral superior aspect of the eye
What muscle is responsible for opening the lacrimal sac and pulling tears in?
Lacrimal part of orbicularis oculi M.
Where does aqueous humor come from?
Ciliary processes
Blockage of the scleral venous sinus can result in what disorder?
Glaucoma
Rupture of blood vessels in the anterior chamber of the eye can result in what disorder?
Hyphema
What attaches the ciliary processes to the lens of the eye?
Zonular fibers/suspensory ligament of the lens
What is the action of the ciliary muscles for near vision? What is the effect on the lens?
Contract and decrease size of ciliary body, reduces tension on suspensory ligament
Lens become round
What is the action of the ciliary muscles for far vision? What is the effect on the lens?
Relaxed ciliary muscles and increased size of ciliary body, increases tension on suspensory ligament
Flatten lens
