11. Eye and Eye Movements (Keim) Flashcards Preview

15. Neuro Test 1 > 11. Eye and Eye Movements (Keim) > Flashcards

Flashcards in 11. Eye and Eye Movements (Keim) Deck (45)
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1
Q

What are the 3 layers of the eye and their sublayers?

A
2
Q

Which muscles of the eye are not innervated by the oculomotor nerve?

Which nerves are they innervated by instead?

A

Lateral rectus - abducens

Superior oblique - trochlear nerve.

3
Q

Why do patients with trochlear palsy lean to one side?

Which side do they lean to?

A

Pts with trochlear palsy lean away from the affected side because the affected eye is extorsioned. They turn to compensate.

4
Q

What nerve innervates levator palpebrae superioris?

A

Occulomotor (CN III)

5
Q

What are the causes discussed for a central retinal artery occlusion?

A

Atherosclerosis or embolism.

6
Q

What nerve innervates the superior and inferior rectus muscles?

A

The oculomotor nerve.

7
Q

Which cranial nerve comes out dorsally from the midbrain?

A

Trochlear.

8
Q
A
9
Q

Diagnosis?

(ignore the arrow, that is making a different point.)

A

Papilledema.

10
Q

What nerves does the frontal nerve of the orbit branch into?

A

Supraorbital N

Supratrochlear N

11
Q

What is the action and innervation of the lateral rectus muscle?

A

Abduction of the eyeball.

Abducens CN VI

12
Q

What is the other name for the suspensory ligament of the lens?

What two structures does it attach?

A

Zonular fibers.

Ciliary body and the lens.

13
Q

Describe the presentation for occulomotor palsy.

What muscles are working?

A

Superior oblique and lateral rectus work, causing the eye to go “down and out.”

We also see ptosis, due to the loss of the occulomotor control of the levator palpebrae superioris.

The pupil will be dilated because the parasympathetics to the eye also travel in the oculomotor nerve.

14
Q

What can cause glaucoma?

A

Increased intraocular pressure - possibly due to blockage of the scleral venous sinus.

15
Q

Describe the corneal reflex.

A

When the cornea is touched with cotton, the nasociliary nerves will carry the general somatic afferent information back to the trigeminal sensory nucleus or spinal trigeminal nucleus.

Those nerves will then synapse with the facial nucleus.

The nerves out of the facial nucleus will activate the orbicularis oculi (ocular and palpebral parts).

16
Q

What causes complete ptosis, and what causes partial ptosis?

A

Complete ptosis is due to damage of the oculomotor nerve.

Partial ptosis is due to damage of the sympathetics (tarsal muscle) such as in Horner Syndrome.

17
Q

What cranial nerve carries parasympathetics for tear production?

A

Facial nerve.

(Via greater petrosal.)

18
Q

Parasympathetics to the eye run with what nerve?

Sympathetics to the eye run with what nerve?

A

Parasympathetics: Oculomotor nerve

Sympathetics: Nasociliary nerve (from the ophthalamic branch of the

19
Q

What type of vision would someone be using if their ciliary muscles were relaxed, near vision or far vision?

A

Far vision.

20
Q

Why is the central retinal artery so important?

A

Because it is the only artery to the retina, and if it is occluded, you will end up blind.

21
Q

What sorts of things can cause central retinal vein occlusion?

A

Hardening or hypertension of the central retinal artery.

Increased intracranial pressure.

22
Q

Which muscles are innervated by the superior and inferior branches of the oculomotor nerve respectively?

A
  • Superior
    • Levator palpebrae superioris
    • Superior rectus
  • Inferior
    • Inferior oblique
    • Inferior rectus
    • Medial rectus
23
Q

What muscles are the adductors of the eye?

A

Superior rectus

Inferior rectus

Medial rectus

24
Q

What is Müller’s muscle?

A

The tarsus muscle.

25
Q

Diagnosis?

A

Central retinal artery occlusion.

26
Q

Diagnosis?

A

Central retinal vein occlusion.

27
Q

Will damage to the lacrimal nerve cause an inability to produce tears?

A

Close to the lacrimal gland (after the communicating branch from the nerve of the pterygoid canal) - yes, otherwise no.

28
Q

What nerves does the nasociliary nerve branch into?

A

Anterior ethmoidal N

Posterior ethmoidal N

Infratrochlear N.

Long ciliary nerves.

Contribution to the ciliary ganglion.

29
Q

What two cranial nerves are involved in a pupillary light reflex test?

A

Optic (CN II)

Oculomotor (CN III)

30
Q

How does general somatic afferent sensory innervation reach the brain from the bulb of the eye?

A

Afferent fibers run through the long ciliary nerve, OR the short ciliary nerve and ciliary ganglion, to the nasociliary nerve, to the ophthalmic branch of the trigeminal nerve, to the sensory root of the trigeminal nerve.

(Green Sensory Heading)

31
Q

What two muscles and their nerves help to maintain an open eyelid?

A

The levator palpebrae superioris M. via the oculomotor N.

The tarsus M. via the sympathetics from T1-T4.

32
Q

What are the bones of the orbit?

A

Maxillary

Frontal

Zygomatic

Ethmoid

Lacrimal

Sphenoid

Palantine

Many Friendly Zebras Enjoy Lazy Summer Picnics

33
Q

To test superior and inferior oblique, will you have the patient look medially or laterally?

A

Medially.

34
Q

Describe the pupillary light reflex.

A

Requires Optic (CN II) to see the light, and oculomotor (CN III) to constrict the pupil.

When the light is shined, the retina cells pick up the signal and send their signal to where they synapse in the pretectal nucleus.

Cells from the pretectal nucleus send the signal to the Edinger-Westphal nucleus, which respond back to the preganglionic parasympathetic neurons traveling with the oculomotor nerve.

Those postganglionic parasympathetic nerve fibers then activate the pupillary constrictor muscle.

35
Q

To test superior and inferior rectus, will you have the patient look medially or laterally?

A

Laterally.

36
Q

What muscles are the abductors of the eye?

A

Superior oblique

Inferior oblique

Lateral rectus

37
Q

Which nerves run through the common tendinous ring?

Which nerves run outside the common tendinous ring?

A
  • Within
    • Superior branch of the oculomotor N.
    • Inferior branch of the oculomotor N.
    • Nasociliary N.
    • Abducens N.
    • Optic N.
  • Without
    • Trochlear N.
    • Frontal N.
    • Lacrimal N.
38
Q

Through which route do the parasympathetics reach the eye?

A

Via the parasympathetic root of the oculomotor nerve synapsing at the ciliary ganglion and then carried by the short ciliary nerve only.

39
Q

Diagnosis?

Describe what happened.

A

Hyphema. Breakage of blood vessels in the anterior chamber of the eye.

40
Q

Describe the flow of aqueous humor in the eye.

A

The ciliary process creates the aqueous humor into the posterior chamber, and it flows into the anterior chamber. From there it flows into a structure called the scleral venous sinus to drain (Schlemm’s Canal).

41
Q

What is the Vidian nerve?

A

The nerve of the pterygoid canal.

42
Q

Describe the flow of tears from start to finish.

A

Lacrimal gland -> eye -> lacrimal canaliculus -> lacrimal sac -> nasolacrimal duct.

43
Q

What are the actions of the superior rectus m?

A

Elevates, adduct, intorsion.

44
Q

Which part of the orbit do “blowout fractures” of the orbit typically affect?

Which sinuses can things prolapse into?

A

The inferior or medial parts.

Inferior: Maxillary sinus

Medial: Ethmoid sinus

45
Q

Starting medially and travelling inwards, what are the contents of the cavernous sinus?

A

Internal Carotid A.

Oculomotor N.

Trochlear N.

Abducens N.