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Foramen magnum

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A large opening in the anterior inferior portion of occipital bone in the cranium that serves anoutlet of the spinal cord and medulla to enter from the skull to the vertebral column.


Foramen magnum is one of the largest openings or canals situated at the base of the skull to permit the route ofblood vessels, nerves, cerebrospinal fluid and connective tissue into and out of the brain. It also covey the spinal component of the accessory nerve into the cranial fossa andtransmits the anterior and posterior spinal arteries, vertebral arteries and alar ligaments.

The foramen magnum in humans areexceptional compare to other mammals since it is frontward in the occipital bone from the back of the skull beneath the center mass of the skull and brain, thus neck muscles of humans need not to be as tough in order to hold the head upright. Unlike inquadriped mammals in order to create better balance the neck bones and muscles areproportionately smaller. On the other hand, head and brains in humans are relatively larger compare to the upper cervical spine, as consequent human aresusceptible toslip and fall kinds of injuries.

Word Origin: foramen= “hole” + magnum= “large

Synonym: great foramen

See also:

cranial bone

posterior cranial fossa