Cranial foramina

The cranial foramina are the holes that exist in the skull to allow the passage of structures into and out of the cranium. Some clefts/fissures, which are not entirely surrounded by bone, and canals, which are longer than their diameter, are often included in this category.

Most cranial foramina are at the base of skull:

Additional cranial foramina include congenital calvarial defects, such as​ parietal foramen.

Other foramina in the skull are not strictly related to the cranium (bones surrounding the intracranial cavity) but rather to the bones of the face and jaw: