What is the Foramen Magnum?
A foramen is an aperture that permits the passage of structures from one region to another and in our skull base there are various, in which the largest one is the Foramen Magnum.
Foramen Magnum (“the Great hole”) is part of the occipital bone, located within the posterior cranial fossa (the posterior area of the skull base). This aperture has got an oval shape with a large antero-posterior diameter.
Why is it so important?
Foramen Magnum allows the communication between the cranial cavity and the vertebral canal, or in other words, between the brain and the spinal cord.
This opening is traversed by vital structures including: lower end of medulla oblongata, meninges, the vertebral arteries, the anterior and posterior spinal arteries, the dural veins; and also the spinal roots of accessory nerves.
Pathologies associated with this structure:
Foramen magnum meningioma
Cerebral herniation
Chiari malformations
Interesting fact - human evolution
Some researchers believe that the location of this foramen explains why we are able to walk. Suggesting that in order to have an upright posture, the foramen magnum moved itself forward – an evolutionary process occurred over millions of years!
