|Bone: Foramen magnum|
|Occipital bone. Inner surface.|
|Gray's||subject #31 129|
In anatomy, in the occipital bone, the foramen magnum (Latin: 'great hole') is one of the several oval or circular apertures in the base of the skull (the foramina), through which the medulla oblongata (an extension of the spinal cord) enters and exits the skull vault.
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 membrana tectoria and alar ligaments.
In humans, the foramen magnum is farther underneath the head than in great apes. Thus, in humans, the neck muscles do not need to be as robust in order to hold the head upright. Comparisons of the position of the foramen magnum in early hominid species are useful to determine how comfortable a particular species was when walking on two limbs (bipedality) rather than four.
The foramen magnum is the border line above which is the brain, and below, the spinal cord.
- SUNY Figs 22:4b-10
- Norman/Georgetown cranialnerves (XI)
- Roche Lexicon - illustrated navigator, at Elsevier 34257.000-1
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant. Template:Skull
Foramina of the skull (and canals, fissures, meati, and hiati)
|Anterior cranial fossa||to Orbit: ethmoidal foramina (anterior, posterior)|
to Nasal cavity: olfactory foramina (CN-I) - foramen cecum
|Middle cranial fossa||to Orbit: optic canal (CN-II) - superior orbital fissure (CN-III,IV,V1,VI) foramen lacerum - hiatus for greater petrosal nerve - hiatus for lesser petrosal nerve - sphenoidal emissary foramen|
|Posterior cranial fossa||internal auditory meatus/facial canal/stylomastoid foramen (CN-VII,VIII) - jugular foramen (CN-IX,X,XI) - foramen magnum (CN-XI) - hypoglossal canal (CN-XII) - condylar canal - mastoid foramen|
|Orbit||to Nasal cavity: nasolacrimal canal|
Pterygopalatine fossa: inferior orbital fissure
|Pterygopalatine fossa||to Nasal cavity: sphenopalatine foramen Nasopharynx: palatovaginal canal|
|Nasal cavity||to Oral cavity: incisive canals - incisive foramen|
|Other||external acoustic meatus - mandibular foramen - mental foramen - parietal foramen - petrotympanic fissure - semilunar hiatus|
de:Foramen magnumhu:Öreglyuksk:Veľký otvor
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