Fourth ventricle

Dr Jeremy Jones et al.

The fourth ventricle is one of the components of the ventricular system in the brain, along with the lateral and third ventricles. It extends from the cerebral aqueduct (of Sylvius) to the obex and is filled with CSF.

CSF enters the ventricle via the cerebral aqueduct and leaves via one of four routes:

It is characteristically diamond-shaped in cross-section and located within the pons or upper part of the medulla oblongata. The "roof" (dorsally) is formed by the cerebellum and the "floor" (ventrally), by the rhomboid fossa. The side "walls" are formed by the cerebellar peduncles.

The obex is the most caudal tip of the fourth ventricle.

Related pathology

See also

Neuroanatomy
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Article information

rID: 5849
Section: Anatomy
Synonyms or Alternate Spellings:
  • 4th ventricle

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