fourth ventricle

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ventricle

 [ven´trĭ-k'l]
a small cavity or chamber, as in the brain or heart.
ventricle of Arantius
1. the rhomboid fossa, especially its lower end.
fourth ventricle a median cavity in the hindbrain, containing cerebrospinal fluid.
ventricle of larynx the space between the true and false vocal cords.
lateral ventricle the cavity in each cerebral hemisphere, derived from the cavity of the embryonic tube, containing cerebrospinal fluid.
left ventricle the lower chamber of the left side of the heart, which pumps oxygenated blood out through the aorta to all the tissues of the body.
Morgagni's ventricle ventricle of larynx.
pineal ventricle an extension of the third ventricle into the stalk of the pineal body.
right ventricle the lower chamber of the right side of the heart, which pumps venous blood through the pulmonary trunk and arteries to the capillaries of the lung.
third ventricle a narrow cleft below the corpus callosum, within the diencephalon between the two thalami.

fourth ven·tri·cle

[TA]
a cavity of irregular tentlike shape extending from the obex rostralward to its communication with the sylvian aqueduct, enclosed between the cerebellum posteriorly and the rhombencephalic tegmentum anteriorly, with a rhomboidal floor (rhomboid fossa) and a tentlike roof; in its caudal part it is formed by the tela choroidea and the posterior medullary velum, in its middle part by the white matter of the cerebellum, and in its narrowing rostral part (recessus superior) by the anterior medullary velum. The fourth ventricle reaches its greatest width at the pontomedullary transition, where it expands laterally behind the cerebellar peduncles into the spoutlike lateral recess, and its greatest height at the fastigial recess, which reaches up into the cerebellar white matter. Direct communication of the brain's ventricle system and the subarachnoid space is established at the level of the fourth ventricle by a median opening in the tela choroidea, the medial aperture of the foramen of Magendie, which opens into the cerebellomedullary cistern, and on both sides by the lateral aperture or foramen of Luschka, which connects the lateral recess with the lateral cerebellomedullary cistern.

fourth ven·tri·cle

(fōrth ven'tri-kĕl) [TA]
A cavity of irregular shape extending from the obex rostrad to its communication with the sylvian aqueduct, enclosed between the cerebellum dorsally and the rhombencephalic tegmentum ventrally, having a rhomboid-shaped floor (rhomboid fossa) and a tentlike roof that in its caudal part is formed by the tela choroidea and the posterior medullary velum, in its middle part by the white matter of the cerebellum, and in its narrowing rostral part (recessus superior) by the anterior medullary velum. The fourth ventricle reaches its greatest width at the pontomedullary transition, where it expands laterally behind the cerebellar peduncles into the spoutlike lateral recess, and its greatest height at the fastigial recess, which reaches up into the cerebellar white matter. Direct communication between the ventricular system and the subarachnoid space is established at the level of the fourth ventricle by a median opening in the tela choroidea, the medial aperture of the foramen of Magendie, which opens into the cerebellomedullary cistern, and on both sides by the lateral aperture or foramen of Luschka, which connects the lateral recess with the interpeduncular cistern.

fourth ventricle

The centrally placed, rearmost of the four fluid-filled spaces in the brain. This tent-shaped cavity for cerebrospinal fluid lies immediately behind the PONS of the brainstem and immediately in front of the CEREBELLUM. It communicates with the aqueduct of the midbrain, in front, and with the central canal of the spinal cord, below.