Eye and Eye Movements Flashcards

1
Q

What bones form the orbit?

A
Frontal
Ethmoid
Sphneoid (greater wing) 
Zygomatic 
Lacrimal 
Maxillary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Draw the anatomical relationship of the paranasal sinuses - frontal, ethmoid and maxillary sinuses

A

REfer to drawings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens if you get an infection in the ethmoid sinuses?

A

Infection can erode to the orbits and cause optic neuritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Orbital Blow out fractures:

A

Fracture of the orbital walls caused by indirect trauma
Usually occurs medially and inferiorly involving the maxillary bone
Contents of the orbit may prolapse and entrapped in the maxillary sinus
Clinical: diplopia, globe ptosis, exophthalmos (protrusion of eyeball)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the position of the orbital globe

A

Medial walls are parallel but lateral walls are right angles to each other , causing the axes of the orbit to diverge at 45 degrees while the axes of gaze are parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Draw out the different movements of the pupil and their axis

A

Refer to drawings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Draw the schematic for remembring EOM actions:

A

Refer to drawings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How would you clinically test the EOMs?

A

H test, Superior/inferior rectus and obliques are tested through actions opposite their actions
So to test Inferior/superior Oblique: Adduct the eye (since these are abductors)
To test the superior/inferior rectus: Abduct the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do you discriminate between muscle and nerve dysfunction?

A

Trap one muscle and test the muscle doing opposite the movement. Trapping means the visual gaze axis is perpendicular to muscle fiber direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Long ciliary N. and short ciliary N. innervation:

A

Sensation to cornea and sympathetic to dilator pupilae

Short ciliary carries parasympathetic fibers to dilator pupillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Long ciliary carries … fibers

Short Ciliary carries …. Fibers

A

Sympathetic to dilator pupilae

parasympathetic to sphincter pupilae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which nerves go through the superior orbital fissure?

What is the tendinous ring? Which nerves go through it?

A

Lacrimal, frontal and trochlear. Do NOT pass through the tendinous ring
Formed by the rectus muscles. Oculomotor, Abducens, Nasociliary (also passes through the superior orbital fissure)

*OAN passes through both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Optic nerve passes through ….

A

Tendinous ring and optic canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Draw the sympathetic pathway of eye movement:

A

REfer to drawings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do the sympathetic fibers of the external carotid plexus innervate?

A

Salivary glands, sweat glands, blood vessels (vasoconstriction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What comes off the internal carotid plexus:

A

Deep petrosal N. (sympathetic). Joins greater petrosal N. (parasympathetic) to form the N. of the pterygoid canal. Sympathetic fibers join the parasympathetic pterygopalatine ganglion to the blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is the eye sympathetically innervated?

A

From the Internal carotid plexus, sympathetic fibers jump on to nerves that will get them where they wanna go.
Via ciliary ganglion (parasympathetic) then short ciliary N. > dilator pupilae (do sympathetic stuff!)
Via the nasociliary N. > dilator pupilae.
Via the Superior root of CN III then > superior tarsal muscle (keep eyes open!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Horner’s syndrome:
Cause
Clinical

A

Damage to the sympathetic innervation of the head and neck. No sympathetics = parasympathetics take over.
Constricted pupil, ptosis (eyes staying shut), anhydrosis (no sweat), vasodilation leading to flushing of skin,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Draw the parasympathetic pathway of eye movement:

A

Refer to drawings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe parasympathetic innervation to the eye:

A

From parasympathetic root of the Ciliary ganglion > Synapse at ciliary ganglion > post synaptic parasympathetic travels to the sphincter pupilae and ciliary muscle to constrict the pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Trochlear palsy:

A

Superior oblique paralysis. Eye is laterally rotated.

Patient presents with eye tilted away from affected side. Diplopia worse on downward gaze.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Abducens palsy:

A

Cannot look laterally with affected eye

23
Q

Oculomotor Palsy:

A

Eye is down and out due to loss of ocular muscle innervation. SO and LR are still intact.
Complete ptosis due to loss of innervation to LPS
Pupil dilation due to loss of parasympathetic innervation to pupil (Oculomotor carries parasympathetics)

24
Q

Explain the pupillary light reflex:

A

4 neuron pathway. Light sensed by CN II (sensory) and will synapse to pretectal nucleus > pretactal nucleus cells synapse to Edinger-Westphal nucleus > Preganglionic parasympathetic neurons travel with CN III (motor portion) and will synapse to ciliary ganglion > postganglionic parasympathetic neurons synapse in the pupillary constrictor muscle and constrict the pupil

25
Q

Explain the corneal reflex:

A

Corneal receptor detect touch and irritation > travel in CN V and synapse in trigeminal sensory nucleus or spinal trigeminal nucleus > cells at the TSN project to facial nucleus > neuron in facial nerve will cause eye to blink

26
Q

Layers of the eyeball:

A

Fibrous (sclera and cornea)
Vascular (choroid - full of blood vessels, ciliary body and iris)
Inner (retina)

27
Q

Draw the cross section of the optic nerve and its contents:

A

Refer to drawings

28
Q

Difference between Levator Palpebrae superioris and Lateral Tarsal muscle:

A

Lateral tarsal muscle keeps the eye open. Innervated by sympathetic nerve fibers

29
Q

Characteristics of bacterial vs. viral conjunctivitis

A

Bacterial: crusty eyes, discharge
Viral: Red with no discharge

30
Q

Subconjunctival hemorrhage:

A

Rupture of eye vessel between the sclera and bulbar conjunctiva
Can happen whenever you increase your interabdominal pressure (like blowing your nose)

31
Q

Complete ptosis:

A

Complete closure of eye

Paralysis of the levator palpebrae superioris due to damage of CN III or one of its branches.

32
Q

Tarsal ptosis:

A

Paralysis of the tarsal muscle. Somewhat close eyes.
Innervated by postganglionic sympathetic fibers (from T1 level)
Horner’s usually due to Tarsal muscle paralysis due to sympathetic nerve damage

33
Q

Papilledema

A

Caused by increased intracranial pressure (ICP) in the subarachnoid space and pushing on the optic disc.
Emergent as cause of increased ICP needs to be determined.

34
Q

Where do the arteries supplying the eye branch from?

A

Internal carotid artery

35
Q

Anastomosis of eye arteries:

A

Supraorbital A. anastomose with Superficial temporal A.
Supratrochlear A. anastomose with Angular
Lacrimal anastomose with middle meningeal
Ethmoidal anastomose with sphenopalatine

36
Q

Draw the arteries of the eye

A

Refer to drawings

37
Q

Importance of anastomosis:

A

Blood flow keeps going despite occlusion.

If ophthalmic a. is blocked, anastomosis takes care of the blood flow by supplying the central retinal artery

38
Q

Central retinal artery:

A

Sole blood supply to the eye (no anastomose). Occlusion will cause organ death

39
Q

Venous supply to the eye:

A

Superior and inferior ophthalmic vein can drain infections in the face to the cavernous sinus and cause meningitis.

40
Q

Central retinal vein occlusion:
Cause
Clinical

A

Hardening of the CRA and HTN in CRA can compress the CRV

Hemorrhages and dilated veins

41
Q

Central Retinal Artery occlusion
Cause
Clinical

A

Artherosclerosis, embolism

Retinal appears white. Cherry red spot. Veins and arteries attenuated

42
Q

What is the lacrimal apparatus?

A

Consists of the lacrimal gland, lacrimal canaliculi, lacrimal sac and nasolacrimal duct

43
Q

Draw the lacrimal apparatus

A

Refer to drawings

44
Q

Drainage of tears:

A

Lacrimal gland > lacrimal canaliculi > puncta “wick” the tear into the lacrimal sac > through the nasolacrimal duct > inferior nasal meatus

45
Q

Lacrimal part of the orbicularis oculi

A

Attaches to the lateral side lacrimal sac, opening it up when you blink and suck it down the lacrimal aparatus

46
Q

Draw the parasympathetic innervation of the lacrimal gland

A

REfer to drawings

47
Q

Describe the process of tear production:

A

Greater petrosal N.(parasympathetics from CN VII) and deep petrosal n. form the N. of the pterygoid canal > Parasympathetic fibers synapse to the pterygopalatine ganglion > fibers travel with v2 > zygomaticotemporal n. and its communicating branch to get to lacrimal n. > synapse at lacrimal gland

Only lesions on this pathway can affect tear production. Trigeminal nerve is just a highway.

48
Q

Four eye chamber:

A

Ciliary body
Ciliary process
Anterior chamber
Posterior chamber

49
Q

Describe the flow of the aqueous humor:

A

Ciliary process secrete the aqueous humor > posterior chamber >anterior chamber > flow into the scleral venous sinus (Schlemm’s canal)

50
Q

Draw the flow of the aqueous humor

A

Refer to drawings

51
Q

Glaucoma:

Cause

A

Blockage of the Schlemm’s canal leading to increased pressure

52
Q

Hyphema
Cause
Clinical

A

Rupture of blood vessels that supply the anterior chamber

53
Q

Ciliary body mechanics (effect on lens)

A

Contraction of ciliary muscles decreases the size of the ciliary body
Reduces the tension on the suspensory ligament and lens becomes more rounded (for near vision)

54
Q

2 types of conjunctiva:

A

Palpebral (lines inner most part of the eyelid)

Bulbar (ocular) conjunctiva (lines the outermost part of the eyeball