Orbital fissure
Fissura orbitalis
Definition
The orbital fissure is an opening in the floor of the orbit through which the trochlear, oculomotor, ophthalmic, and abducens nerves pass, communicating with the ocular annexes and certain blood vessels.
It forms at the articulation between the wings of the basisphenoid bone and the wings of the presphenoid bone.
Variation :
In ruminants, the orbital fissure and the foramen rotundum fuse to form the latter.
References
König HE, Liebich HG. Anatomia dos Animais Domésticos. 6ª edição. Porto Alegre: Artmed; 2016.
Evans HE, De Lahunta A. Guide to the Dissection of the Dog. 8ª edição. Philadelphia: Saunders; 2016. Orsini JA, Grenager NS, De Lahunta A. Comparative veterinary anatomy: a clinical approach. Academic Press, 2021.
Gelatt KN, Plummer CE. Essentials of veterinary ophthalmology. 4ª edição. Nova Jersey: Wiley-Blackwell; 2022.
