eye function and pathology

Question 1

what are the three controls of eye movement

Answer 1

scanning - eyes flick from one visual field to another
tracking - eyes follow an object across the visual field (poor function results in nystagmus)
compensation - holding gaze on an object of interest during movements of the head (vestibulo-ocular/fixation reflex)

Question 2

what happens with oculomotor nerve 3 palsy

Answer 2

in a complete case you get. ptosis, mydriasis which is decreased tone of constrictor pupillae muscle and down and out (unopposed left superior oblique and lateral rectus)

and partial is characterised by increased ICP putting pressure on CN3

Question 3

what will an aneurysm of the posterior communicating artery result to?

Answer 3

pupilary dilation - mydriasis

Question 4

what happens in the event of abducens nerve palsy

Answer 4

the eye is fully adducted by the unstopped pull of the medial rectus

Question 5

what is the optic nerve covered by

Answer 5

covered by meninges and extension of sub-arachnoid space

Question 6

optic tract results in what pathways?

Answer 6

Ipsilateral (nasal) and contralateral (temporal)

Question 7

what the two roots of the optic tract

Answer 7

• medial - medial geniculate (10%)
• Lateral - lateral geniculate (90%)

Question 8

where is the primary visual cortex found

Answer 8

• occupies walls of calcarine sulcus (also called striate cortex)