Head – Orbits, Face & Mandibular Region

ORBITS

List the contents in the superior orbital fissure, dividing the contents based on its relation to the annulus of Zinn (10 marks)

EXTERNAL to Annulus of Zinn

1. Lacrimal nerve (part of CNV1)
2. Frontal nerve (part of CNV1) – forms supratrochlear and supraorbital
3. Trochlear nerve CN4 to Superior oblique muscle
4. Superior ophthalmic vein

WITHIN the Annulus of Zinn

• Within the optic canal
  1. Optic nerve CN2
  2. Ophthalmic artery
• Not within the optic canal but within Annulus of Zinn
  1. Superior division of CN3
  2. Inferior division of CN3
  3. Nasociliary nerve (part of CNV1) travels medial orbital wall (close to nose) to give off long ciliary nerve, nerve to ciliary ganglion, posterior and anterior ethmoidal nerve, and infratrochlear nerve
  4. Abducens nerve CN6 to lateral rectus