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Third ventricle

The third ventricle (ventriculus tertius) is one of four connected fluid-filled cavities comprising the ventricular system within the human brain. It is a median cleft in the diencephalon between the two thalamus, and is filled with cerebrospinal fluid (CSF).

It is in the midline, between the left and right lateral ventricles. Running through the third ventricle is the Interthalamic adhesion, fibers which connect the two thalami.

The posterior wall is the base of the pineal gland.

Gross anatomy

The third ventricle is a median cleft between the two thalami (see thalamus) and is bounded laterally by them and the hypothalamus. Its anterior wall is formed by the lamina terminalis, and posteriorly there is the pineal recess. There are two protrusions on the anterior surface of the third ventricle:

supra-optic recess (above the optic chiasm)

infundibular recess (above the pituitary stalk)

The third ventricle communicates with the lateral ventricles via the foramen of Monro (interventricular foramen) and with the fourth ventricle via the aqueduct of Sylvius (cerebral aqueduct).

Anterior recesses of the third ventricle


see Third ventricle tumor.

Third ventricle floor

see Third ventricle approach

third_ventricle.txt · Last modified: 2017/06/07 21:26 by administrador