Orbit

Question 1

Functions of the eyelid?

Answer 1

Protect eyelid, spread lacrimal secretions across surface and shade eyelid

Question 2

What is the palpebral fissure?

Answer 2

Space between the corners of the eyes (medial and lateral canthi) – opening of eyelids basically

Question 3

Where is the ciliary gland located?

Answer 3

Within the subcutaneous tissue of the eye

Question 4

What results from ciliary gland infection?

Answer 4

Sty

Question 5

Origin, insertion, innervation and action of levator palpebrae superioris

Answer 5

O: lesser wing of sphenoid
I: Skin of upper eyelid and tarsal plate
IN: oculomotor nerve (III)
Action: elevate eyelid

Question 6

Origin, insertion, innervation and action of superior oblique

Answer 6

O: Body of sphenoid
I: Through trochlea to sclera
IN: Trochlear nerve (IV)
Action: Depress and ABduct eye

Question 7

Origin for the rectus muscles?

Answer 7

Common tendinous ring

Question 8

Insertion for the rectus muscles?

Answer 8

Sclera posterior to cornea

Question 9

One rectus muscle not innervated by oculmotor nerve?

Answer 9

Lateral rectus - abducens nerve (VI)

Question 10

Ptosis?

Answer 10

Drooping of upper eyelid

Question 11

What can cause complete ptosis?

Answer 11

Destruction of the oculomotor nerve or one of its branches to levator palpebrae superioris

Question 12

What muscle originates at the lesser wing of the sphenoid but inserts on the tarsal plate of upper lid?

Answer 12

Tarsal muscle (of Muller)

Question 13

What causes slight ptosis?

Answer 13

Paralysis of tarsal muscle

Question 14

Symptoms of Horner’s syndrome?

Answer 14

Paralysis of tarsal muscle
Slight ptosis
Miosis
Enopthalmos
Anhidrosis and blushing

Question 15

Pupillary constriction due to paralysis of dilator pupillae muscle

Answer 15

Miosis

Question 16

Posterior displacement of the eye

Answer 16

Enopthalmos

Question 17

Inability to sweat normally

Answer 17

Anhidrosis

Question 18

What innervates the tarsal muscle?

Answer 18

Post-ganglionic fibers (smooth muscle)

Question 19

What is the palpebral fascia comprised of?

Answer 19

Tarsus and orbital septum

Question 20

What does the palpebral fascia attach to?

Answer 20

Medial and lateral palpebral ligaments

Question 21

Membrane that lines back of eyelids?

Answer 21

Palpebral conjunctiva

Question 22

Thin, transparent membrane that attaches to eyeball?

Answer 22

Bulbar conjunctiva

Question 23

Describe how tears drain?

Answer 23

• Lacrimal gland
• Lacrimal ducts
• Lacrimal canaliculi
• Lacrimal sac
• Nasolacrimal duct
• • Drains into inferior nasal meatus/turbinate

Question 24

Bones that make up the orbit?

Answer 24

Frontal, zygomatic, maxilla, lacrimal, sphenoid, ethmoid, palatine

Question 25

If bones in the orbit are fractured what can occur?

Answer 25

Intracanalicular portion of optic nerve now vulnerable to ischemia due to loss of blood supply

Question 26

What runs in the optic canal?

Answer 26

CN II and opthalmic artery

Question 27

Where do blow-out fractures occur?

Answer 27

Floor of the orbit

Question 28

What may result from a blow-out fracture?

Answer 28

Sensation loss below the eye where the infraorbital nerve would supply if it was damaged

Question 29

Le-Forte 1

Answer 29

Transverse fracture of maxilla only

Question 30

Le-Forte 2

Answer 30

Pyramid shaped fracture involving maxilla and medial orbit

Question 31

Le-Forte 3

Answer 31

Transverse fracture of many facial bones and orbits - usually separating face from base of skull

Question 32

What can cause a blow-out fracture?

Answer 32

Trauma to front of eyeball

Question 33

What are not cardinal positions of gaze?

Answer 33

Straight up and down

Question 34

What is the chief sensory nerve of the eye?

Answer 34

Nasociliary nerve from V1

Question 35

Describe the direct and consensual corneal reflexes?

Answer 35

Lightly touch cornea Nasociliary nerve endings respond - afferent Facial nerve response - efferent Orbicularis oculi contracts to blink

Question 36

What nuclei are involved in the direct and consensual corneal reflexes?

Answer 36

Descending nucleus of V - sensory | Facial nucleus - motor

Question 37

Main blood supply to orbit?

Answer 37

Opthalmic artery

Question 38

Main blood supply to retina?

Answer 38

Central Artery of retina

Question 39

Terminal branches of opthalmic artery?

Answer 39

Dorsal nasal and supratrochlear

Question 40

Where does the opthalmic artery originate?

Answer 40

Internal carotid artery

Question 41

What vein in the eye drains into the cavernous sinus?

Answer 41

Superior opthalmic vein

Question 42

What are the 3 aspects of the triad of accommodation?

Answer 42

Convergence of vision Pupillary constriction Thickening of the lens

Question 43

Result of a syphilis infection; Pupils are unreactive to light but constrict during accommodation

Answer 43

Argyll-Robertson pupil

Question 44

Describe papilledema

Answer 44

INCREASED INTRACRANIAL PRESSURE restricts venous return from retina which causes swelling of optic disc

Question 45

Result of a lesion on ciliary ganglion; Initially pupil is unreactive to light but if convergence is maintained the pupil will slowly constrict

Answer 45

Holmes-Adie pupil