Foramen spinosum

Foramen spinosum
The inner surface of the sphenoid bone, with the foramen spinosum labelled at the left, second from the bottom.
The inner surface of the base of the skull, with the sphenoid bone yellowed. The foramen spinosum is visible at the bottom right of the bone.
Details
Identifiers
Latin	Foramen spinosum
Dorlands /Elsevier	f_12/12373713
TA	A02.1.05.038
FMA	53156
Anatomical terms of bone []

The foramen spinosum is one of two foramina located in the base of the human skull, on the sphenoid bone. It is situated just anterior to the spine of the sphenoid bone, and just lateral to the foramen ovale. The middle meningeal artery, middle meningeal vein, and the meningeal branch of the mandibular nerve pass through the foramen.

The foramen spinosum is often used as a landmark in neurosurgery, due to its close relations with other cranial foramina. It was first described by Jakob Benignus Winslow in the 18th century.

The foramen spinosum is a foramen through the sphenoid bone situated in the middle cranial fossa. It is one of two foramina in the greater wing of the sphenoid bone. The foramen ovale is one of these two cranial foramina, situated directly anterior and medial to the foramen spinosum. The spine of sphenoid falls medial and posterior to the foramen. Lateral to the foramen is the mandibular fossa, and posterior is the Eustachian tube.

The foramen spinosum varies in size and location. The foramen is rarely absent, usually unilaterally, in which case the middle meningeal artery enters the cranial cavity through the foramen ovale. It may be incomplete, which may occur in almost half of the population. Conversely, in a minority of cases (less than 1%), it may also be duplicated, particularly when the middle meningeal artery is also duplicated.