Eye And Eye Movement (extra)

Question 1

How to test superior and inferior rectus ms.?

Answer 1

Abduct eye with lateral rectus m and raise/lower eye. Only SR m or IR m can work on eye if LR m abducts.

Question 2

How to test superior oblique andingerior oblique ms.?

Answer 2

When eyes addicted by MR m, only SO m and IO m can work on eye.

Question 3

Sensory innervation of the eye

Answer 3

Nasociliary n (V1) —> long ciliary n —> choroid, iris, cornea

Question 4

SNS to the eye

Answer 4

Sympathetic root synapse in ciliary ganglion and travels to dilator papillae m and tarsal ms.

Question 5

PSNS to eye

Answer 5

CN III synapses in ciliary ganglion with short ciliary n and acts on sphincter pupillae m and ciliary m/body

Question 6

Trochlear palsy

Answer 6

Head tilts away from affected side. Double vision worse on looking down.

Question 7

Abducens palsy

Answer 7

Cannot look laterally

Question 8

Oculomotor palsy

Answer 8

Down and out eye
Complete ptosis
Pupillary dilation

Question 9

Pupillary light reflex (4)

Answer 9

1. Retinal cells of CN II sense light and synapse in protectable nucleus.
2. Cells from pretectal nucleus synapse in Edinger-Westphal nucleus.
3. Preganglionic cells synapse in ciliary ganglion.
4. Postganglionic cells will innervate pupillary constrictor m.

Question 10

Corneal reflex (3)

Answer 10

1. Receptors in cornea detect irritant, travel in CN V, and synapse in trigeminal nucleus.
2. Cells from trigeminal nucleus projects in facial nucleus.
3. Facial n will cause eye to blink.

Question 11

Fibrous layer of eye

Answer 11

Sclera and cornea

Question 12

Vascular layer of eye

Answer 12

Choroid, ciliary body and iris

Question 13

Inner layer of eye

Answer 13

Retina

Question 14

Palpebrae conjunctiva

Answer 14

On inner eyelid

Question 15

Bulbar conjunctiva

Answer 15

On outermost eye

Question 16

Superior tarsal m.

Answer 16

Innervated by SNS. Partially closes eye. Partial ptosis is affected.

Question 17

What muscle closes eyelid?

Answer 17

Orbicularis oculi m.

Question 18

Venous drainage from eye into the cavernous sinus

Answer 18

Vortices veins drain into superior ophthalmic v and inferior ophthalmic v to cavernous sinus.

Question 19

Venous drainage to Pterygoid plexus

Answer 19

Infraorbital v (from facial v) and from inferior ophthalmic v send a branch to pterygoid plexus

Question 20

Tear production (3)

Answer 20

1. Greater petrosal n (CN VII) and deep petrosal n become N of pterygoid canal.
2. Will synapse in Pterygopalatine ganglion.
3. Postganglionic fibers will travel on V2 (zygomatic branch) to a communicating branch then to lacrimal n (V1).

Question 21

Lacrimal apparatus and drainage

Answer 21

Lacrimal gland makes tears. They drain into lacrimal canaliculi —> lacrimal sac —> nasolacrimal duct.

Question 22

Flow of aqueous humor (4)

Answer 22

1. Ciliary process secrete aqueous humor into posterior chamber.
2. Flows thru pupil to anterior chamber (nourishes lens and cornea).
3. Drains thru trabecular meshwork to sclera venous sinus.
4. Humor removed by limbdal plexus.

Question 23

Relationships of the sinuses to the orbit

Answer 23

Frontal sinuses superior
Maxillary sinuses inferior
Ethmoid sinuses medial
Sphenoid sinuses posterior

Question 24

Orbital blow out fx

Answer 24

From indirect trauma.
Occurs medially and inferiorly involving maxillary bone.
Contents can be trapped in maxillary sinus.
Double vision, exophthalmos.

Question 25

Angle of axis of orbit

Answer 25

45

Question 26

Angle of the lateral walls of orbit

Answer 26

90

Question 27

What axis is parallel?

Answer 27

Orbital axis (axes of gaze)

Question 28

Intorsion vs extorsion

Answer 28

Intorsion (medial rotation) | Extorsion (lateral rotation)

Question 29

Where do the rectus ms. originate?

Answer 29

Tendinous ring

Question 30

Action of superior oblique m.

Answer 30

Abduct, depress and medially rotate eyeball

Question 31

Action of inferior oblique m.

Answer 31

Abduct, elevate and laterally rotate eyeball

Question 32

Action of inferior rectus m.

Answer 32

Depresses, adducts and laterally rotates eyeball

Question 33

Action of superior rectus m.

Answer 33

Elevates, adducts and medially rotates eyeball

Question 34

Adductors of eye

Answer 34

Medial rectus m. | Superior and inferior rectus ms.

Question 35

Abductors of eye

Answer 35

Lateral rectus m. | Superior and inferior oblique ms.

Question 36

Elevate eyes

Answer 36

SR m. | IO m.

Question 37

Abduct and elevate

Answer 37

IO m.

Question 38

Adduct and elevate

Answer 38

SR m.

Question 39

Abduct and depress

Answer 39

SO m.

Question 40

Adduct and depress

Answer 40

IR m.

Question 41

Depress eyes

Answer 41

SO m. | IR m.

Question 42

How to test the superior/inferior rectus ms. clinically:

Answer 42

Abduct eye, then have pt look up or down. Can't look up: SR m. Cant't look down: IR m.

Question 43

How to test the superior/inferior oblique ms. clinically:

Answer 43

Adduct eye, then have pt look up or down. Can't look up: IO m. Can't look down: SO m.

Question 44

Which nerves do NOT enter via the tendinous ring?

Answer 44

Lacrimal n. Frontal n. CN IV

Question 45

What muscle keeps eyelid open?

Answer 45

Tarsal ms.

Question 46

Central retinal v. occlusion

Answer 46

Hardening of CRA and HTN can compress the CRV. | Ketchup looking.

Question 47

Central retinal a. occlusion

Answer 47

From atherosclerosis, embolism. | Retina is white. Cherry red spot.

Question 48

Anterior chamber

Answer 48

Between cornea and iris/pupil

Question 49

Posteriro chamber

Answer 49

Between iris pupil and lens/ciliary body

Question 50

How does ciliary body assist in near vision?

Answer 50

Contracts ciliary ms. --> reduced tension on suspensory L. | Lens becomes rounder.