UM1011 Neuroanatomy - Eye and Ear

Which part of the bony wall is likely to be fractured in a orbital wall blowout
fracture?

Answer explanation

These two walls the inferior (floor) and medial wall is made up of bones that have sinuses, the maxillary and ethmoid sinus. This makes these areas of the orbit at risk of fracture as it is hollow spaces and is thus less dense areas.

Identify the bones that make up the bony orbit.

a

b

c

d

e

i

Sphenoid

Frontal

Nasal 

Occipital

Ethmoid

Maxilla

Lacrimal

Zygomatic

Temporal

Identify this skull bone (Tip: It forms part of the floor or inferior wall of the orbit).

What muscle acts to close the eyelids?

Which cranial nerve provides motor innervation to the Orbicularis Oculi m.?

• CN III (Oculomotor n.)

• CN V1 (Opthalamic)

• CN VII (Facial n.)

• CN II (Optic n.)

What two muscles act to elevate the eyelid?

Which of the two muscles that elevate the eyelid is innervated by sympathetic fibres? ​ (a)   ​

• Superior tarsal muscle
• Levator palpebrae superioris

Levator palpebrae superioris is part of the MoFE.

• True

• False

What cranial nerve provides motor innervation to the Levator palpabrae superioris?​

• CN V1 (Opthalamic n.)

• CN VII (Facial n.)
• CN III (Oculomotor n.)

• CN IV (Trochlear n.)

The fibrous layer of the eyeball is its (a)  

• outermost layer
• Middle layer
• Innermost layer