Eye and Eye Movements

Question 1

Trochlear palsy

Answer 1

Head tilts away from affected side

Diplopia worse on downward gaze

Question 2

Horner syndrome

Answer 2

Constriction of pupil (miosis)
Ptosis
Redness and increased skin temperature
Absence of sweating (anhidrosis)
PAM horner

Question 3

Pupillary light reflex

Answer 3

Light sensed by CN II and will synapse in the pretectal nucleus
Cells from pretectal nucleus will synapse in Edinger-Westphal nucleus
Preganglionic parasympathetic neurons will travel with CN III and synapse in ciliary ganglion
Postganglionic parasympathetic neurons synapse in the pupillary constrictor muscle

Question 4

Corneal reflex

Answer 4

Receptors in cornea detect touch and travel in CN V1 axons which synapse in trigeminal sensory nucleus.
Cells from trigeminal nuclei travel to facial motor nuclei
Facial nerve neurons cause orbicularis oculi to blink the eye

Question 5

Fibrous layer of eyeball

Answer 5

Sclera around back and side of eye, cornea towards front

Question 6

Vascular layer of eyeball

Answer 6

Choroid
Ciliary body
Iris

Question 7

Inner layer of eyeball

Answer 7

Retina- contains optic part and Ora serrata

Also has small indent in back called macula

Question 8

Levator palpebrae superioris vs tarsal muscle

Answer 8

LPS is innervated by CN III and if interrupted, results in complete ptosis
Tarsal muscle is innervated by sympathetic fibers originating from T1, and if interrupted results in partial ptosis. Usually involved in horners syndrome

Question 9

Papilledema

Answer 9

Caused by increased intracranial pressure. This is an emergent situation where you quickly need to find the cause

Question 10

The optic artery is a branch from which artery

Answer 10

Internal carotid

Question 11

Central retinal vein occlusion

Answer 11

Eye becomes much more red “ketchup”
Hardening of the central retinal artery or hypertension in central retinal artery can compress CRV
Hemorrhages or dilated veins can also cause this

Question 12

Central retinal artery occlusion

Answer 12

“Pale with a red spot”
Retina appears white with a cherry red spot
Caused by atherosclerosis, embolism

Question 13

Tear production parasympathetic pathway

Answer 13

Greater petrosal from facial nerve joins deep petrosal from carotid plexus, forming nerve of pterygoid canal.
Synapses in pterygopalatine ganglia, postsynaptic fibers travel with Zygomatic branch of V2, then communicating branch, and finally the Lacrimal branch of V1 to enter lacrimal gland

Question 14

Ciliary processes

Answer 14

Secrete aqueous humor which fills anterior and posterior chambers

Question 15

Anterior chamber

Answer 15

Space between cornea and iris/pupil

Question 16

Posterior chamber

Answer 16

Space between the iris/pupil and the lens and ciliary body

Question 17

Blockage of Schlemms Canal (scleral venous sinus)

Answer 17

Can lead to increased pressure and glaucoma

Question 18

Hyphema

Answer 18

Circulating red blood cells in anterior chamber
Grade I- 1/3rd of anterior chamber volume full
Grade II- 1/3-1/2 anterior chamber volume
Grade III- 1/2 anterior chamber volume
Grade IV- entire anterior chamber full “eight ball hyphema”
Caused by rupture of arterial circle of iris

Question 19

Ciliary body muscles

Answer 19

Contraction of ciliary muscles decreases size of ciliary body
Reduces tension on suspensory ligament
Lens becomes more rounded for near vision

Question 20

Choroid layer is continuous with

Answer 20

Ciliary body and then iris - these are vascular layers

Question 21

Bulbar/ocular conjunctiva

Answer 21

Lines the outermost part of the eyeball

Question 22

Palpebral conjunctiva

Answer 22

Lines the innermost part of eyelids