Foramen Lacerum Definition: Foramen Lacerum is a triangular opening located in the middle cranial fossa, allowing for a few vessels to pass through it. It measures about 9mm in length and 7mm in breadth.
Where is Foramen Lacerum located?
The foramen is located between the sphenoid bone, apex of petrous temporal and basilar part of occipital. It is situated anteromedial to carotid canal. The anterior border of Foramen lacerum is formed by the body of sphenoid bone, and its posterior body is formed by petrous apex, while the medial border is formed by basilar part of occipital bone.
Structures passing through Foramen Lacerum
To remember this easily, keep this order “MEIG” as follows:
- Meningeal branch of ascending pharyngeal artery (which is a branch of external carotid artery)
- Emissary vein – Actually a group of veins that connect the pterygoid plexus and intracranial cavernous sinus.
- Internal carotid artery – It partially traverses through the foramen, and the artery, vein of pterygoid canal pass through along with it.
- Greater petrosal nerve – It transits into foramen lacerum before joining the nerve of pterygoid canal
If someone has a nasopharyngeal carcinoma, it finds a route through the foramen lacerum to cavernous sinus, affecting the cranial nerves.
The Foramen Lacerum is filled with connective tissue, and the superior surface of it has the internal carotid artery passing along.