Answer
Foramina are holes. The largest and most important opening in the skull is the foramen magnum. This is where the spinal cord (SC) joins the medulla oblongata of the brain. The function of foramina is to allow passage or transit og nerves and blood vessels.
The foramen magnum is in the occipital bone and in addition to allowing the passage of the spinal cord it also permits the egress of accessory nerve ( CN XI) and the vertebral arteries.
The following are some other skull foramina:
The supraorbital foramen
This foramen is in the frontal bone ; it facilitates the passage of the supraorbital nerve , artery, and
brain. It is also the passageway used by the ophthalmic nerve.
Work Step by Step
The mastoid foramen; is in the temporal bone; it transmits the meningeal artery, and vein , a mastoid vein, and an occipital artery.