- Posterior cranial fossa
Posterior cranial fossa Base of the skull. Upper surface. The Posterior cranial fossa is labeled in green. Latin fossa cranii posterior Gray's subject #47 192 MeSH Cranial+Fossa,+Posterior
This is the most inferior of the fossae. It houses the cerebellum, medulla and pons. Anteriorly it extends to the apex of the petrous temporal. Posteriorly it is enclosed by the occipital bone. Laterally portions of the squamous temporal and mastoid part of the temporal bone form its walls.
- See main article at Foramen magnum
The most conspicuous, large opening in the floor of the fossa. It transmits the medulla, the ascending portions of the spinal accessory nerve (XI), and the vertebral arteries.
Internal acoustic meatus
Lies in the anterior wall of the posterior cranial fossa. It transmits the facial (VII) and vestibulocochlear (VIII) cranial nerves into canal in the petrous temporal bone.
Lies between the inferior edge of the petrous temporal bone and the adjacent occipital bone and transmits the internal jugular vein (actually begins here), the glossopharyngeal (IX), the vagus (X) and the accessory (XI) nerves.
Anterior condylar (hypoglossal) canal
Lies at the anterolateral margins of the f. magnum and transmits the hypoglossal (XII) nerve.
Also visible in the posterior cranial fossa are depressions caused by the venous sinuses returning blood from the brain to the venous circulation: Right and left transverse sinuses which meet at the confluence of sinuses (marked by the internal occipital protuberance).
The transverse sinuses pass horizontally from the most posterior point of the occiput.
Where the apex of the petrous temporal meets the squamous temporal, the transverse sinuses lead into sigmoid (S-shaped) sinuses (one on each side).
These pass along the articulation between the posterior edge of the petrous temporal and the anterior edge of the occipital bones to the jugular foramen where the sigmoid sinus becomes the internal jugular vein.
The posterior cranial fossa is formed in the endocranium, and holds the most basal parts of the brain.
Bones of head and neck: compound structures of skull (TA A02.1.00.002–052, GA 2.178–199) Neurocranium Facial skeletonNasion · Gonion Both Bones of head and neck: Foramina of the skull (and canals, fissures, meati, and hiati) (TA A02.1.00.053–097, GA 2.178–199) Anterior cranial fossa Middle cranial fossaforamen lacerum · hiatus for greater petrosal nerve · hiatus for lesser petrosal nerve · sphenoidal emissary foramen Posterior cranial fossa Orbit Pterygopalatine fossa Other
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posterior cranial fossa — n CRANIAL FOSSA (a) … Medical dictionary
cranial fossa — n any of the three large depressions in the posterior, middle, and anterior aspects of the floor of the cranial cavity: a) the posterior one that is the largest and deepest of the three and lodges the cerebrum, pons, and medulla oblongata called… … Medical dictionary
cranial fossa — noun : one of the three large depressions in the posterior, middle, and anterior aspects of the floor of the cranial cavity which lodge respectively the cerebellum and the temporal and frontal lobes of the two hemispheres of the cerebrum … Useful english dictionary
cranial fossa posterior — f. cranii posterior … Medical dictionary
Middle cranial fossa — Base of the skull. Upper surface. (Middle cranial fossa is the centermost of the three indentations, in pink and yellow.) Latin fossa cranii media Gray s … Wikipedia
Anterior cranial fossa — Base of the skull. Upper surface. (Anterior cranial fossa is the top of the three indentations.) Latin fossa cranii anterior Gray s … Wikipedia
Cranial cavity — Body cavities Cranial cavity … Wikipedia
Fossa — is the Latin word for ditch or trench . It can refer to one of the following:AnatomyIn anatomical terminology, fossa has come to mean a depression or hollow, in general, in a bone. Other parts of the body may be involved, for example, the… … Wikipedia
Posterior fossa — may refer to:* Posterior cranial fossa * Posterior intercondyloid fossa … Wikipedia
fossa cranii posterior — [TA] posterior cranial fossa: the posterior subdivision of the floor of the cranial cavity, lodging the cerebellum, pons, and medulla oblongata; it is formed by portions of the sphenoid, temporal, parietal, and occipital bones … Medical dictionary