Anatomy of foramen magnum

Anatomy of foramen magnum definition The foramen magnum (Latin: great hole) is a large oval opening (foramen) in the occipital bone of the skull in humans and many other animals. It is one of the several oval or circular openings (foramina) in the base of the skull. The spinal cord, an extension of the medulla oblongata, passes through the foramen magnum as it exits the cranial cavity. Apart from the transmission of the medulla oblongata and its membranes, the foramen magnum transmits the vertebral arteries, the anterior and posterior spinal arteries, the tectorial membranes and alar ligaments. It also transmits the accessory nerve into the skull. Compartment: The alar ligament which is attached on each side to the tubercle of occipital condyle on each side of the foramen magnum divides it into an anterior smaller compartment and a posterior larger compartment Structures passing through anterior compartment (osseo-ligamentous compartment) are Apical ligament and tip of dens Upper band of Cruc