Orbit

Question 1

Name the movements of superior Rectus

Answer 1

Adduction
Elevation
Intortion

Question 2

Name the movements Of Inferior Rectus

Answer 2

Adduction
Depression
Extortion

Question 3

Name the movements of medial Rectus

Answer 3

Adduction

Question 4

Name the movement of lateral Rectus

Answer 4

Abduction

Question 5

Name the movement of superior oblique

Answer 5

Abduction
Depression
Intortion

Question 6

Name the movements of inferior oblique

Answer 6

Abduction
Elevation
Extortion

Question 7

Name the bones which form the medial wall of the orbit

Answer 7

Ethmoid
Lacrimal
Maxilla

Question 8

Between which structures does the superior orbital fissure exist?

Answer 8

Greater and lesser wings of the sphenoid bone

Question 9

What structure is inferior to the orbit?

Answer 9

Maxillary sinus

Question 10

Which bone forms the lateral wall of the orbit?

Answer 10

Zygomatic bone

Question 11

Which motor nerve enters the back of the orbit but does not pass through the common tendinous ring?

Answer 11

Trochlea

Question 12

Which structure lies immediately posterior to the orbit?

Answer 12

Cavernous sinus

Question 13

The branch of the Occulomotor nerve to inferior oblique carries which type of autonomic fibres?

Answer 13

Parasympathetic

Question 14

Name the 3 branches of the nasocilliary nerve

Answer 14

Anterior ethmoidal
Posterior ethmoidal
Infratrochlea

Question 15

What are the 3 major branches of V1 in the orbit?

Answer 15

Frontal
Nasocilliary
Lacrimal

Question 16

Name the branches of the frontal nerve

Answer 16

Supratrochlea

Supraorbital

Question 17

Name an artery which supplies the orbit but is not a branch of the ICA.

Answer 17

Recurrent meningeal. This passes through the superior orbital fissure and is a branch of middle meningeal from the maxillary artery.

Question 18

Name the 2 ways in which venous drainage occurs from the orbit.

Answer 18

Into the cavernous sinus, anteriorly into the facial vein via the angular vein.

Question 19

Name the muscles of the eye supplied by sympathetic innervation

Answer 19

Dilator pupillae

Superior tarsal muscle

Question 20

If superior oblique muscle is deinnervated, what position is the eye unable to obtain?

Answer 20

Looking inferiorly and medially.

This is due to weakness of inferior Rectus in this position

Question 21

What position will the eye adopt in loss of CN III

Answer 21

Down and out
With ptosis
Dilated pupil (loss of parasympathetic root)

Question 22

Describe how sympathetic supply to the back of the orbit originates.

Answer 22

This originates in the cervical sympathetic ganglia and traverses into the H and N via the periarterial plexus. The sympathetic root then supplies the ciliary ganglion and sympathetic supply is carried to the eye by short ciliary nerves.

Question 23

What is the suspensory ligament in the orbit?

Answer 23

This is formed by fusion of the fascia of the Rectus muscles on the medial and lateral aspects of the eye which creates a sling to support the eye.

Question 24

How is movement of the eye limited?

Answer 24

Fascia of the medial and Rectus muscles attach to the lacrimal and zygomatic bones by fanning out and therefore limiting eye movement.