Ventricle

A ventricle is a chamber of an organ. For example, the four connected cavities (hollow spaces) in the central portion of the brain and the lower two chambers of the heart are called ventricles.

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A normal cavity, as of the brain or heart. SYN: ventriculus (2) [TA]. [L. ventriculus, dim. of venter, belly]

- Arantius v. SYN: calamus scriptorius.

- cerebral ventricles lateral v., fourth v., third v., cavity of septum pellucidum.

- v. of cerebral hemisphere SYN: lateral v..

- v. of diencephalon SYN: third v..

- double outlet right v. a heterogeneous category of congenital abnormalities as yet unclassified. Basically both great arteries arise in whole or in part from the right v. or an infundibular chamber. Ventricular septal defect is nearly always present.

- Duncan v. SYN: cavity of septum pellucidum.

- fifth v. SYN: cavity of septum pellucidum.

- fourth v. [TA] a cavity of irregular tentlike shape extending from the obex rostralward 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 which 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 v. 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 v. system and the subarachnoid space is established at the level of the fourth v. by a median opening in the tela choroidea, the medial aperture of Magendie's foramen, 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. SYN: ventriculus quartus [TA], v. of rhombencephalon.

- laryngeal v. [TA] the recess in each lateral wall of the larynx between the vestibular and vocal folds and into which the laryngeal sacculus opens. SYN: ventriculus laryngis [TA], laryngeal sinus, Morgagni sinus (3), Morgagni v., sinus laryngeus.

- lateral v. [TA] a cavity shaped somewhat like a horseshoe in conformity with the general shape of the hemisphere; each lateral v. communicates with the third v. through the interventricular foramen of Monro, and expands from there forward into the frontal lobe as the anterior horn as well as caudally over the thalamus as the central part (cella media) or body which, behind the thalamus, curves ventrally and laterally, then forward into the temporal lobe as the inferior horn; from the apex of the curve a variably sized posterior horn extends back into the white matter of the occipital lobe. The large choroid plexus of the lateral v. invades the cella media and the inferior horn (but not the anterior and posterior horn) from the medial side. SYN: ventriculus lateralis [TA], v. of cerebral hemisphere.

- left v. [TA] the lower chamber on the left side of the heart that receives the arterial blood from the left atrium and drives it by the contraction of its walls into the aorta. SYN: ventriculus sinister [TA].

- Morgagni v. SYN: laryngeal v..

- parchment right v. SYN: Uhl anomaly.

- v. of rhombencephalon SYN: fourth v..

- right v. [TA] the lower chamber on the right side of the heart which receives the venous blood from the right atrium and drives it by the contraction of its walls into the pulmonary artery. SYN: ventriculus dexter [TA].

- (right/left) ventricles of heart one of the two lower chambers of the heart. SYN: ventriculus cordis dexter/sinister.

- single v. congenital absence or near total absence of the ventricular septum.

- sixth v. SYN: Verga v..

- sylvian v. SYN: cavity of septum pellucidum.

- v. of Sylvius SYN: cavity of septum pellucidum.

- terminal v. [TA] a dilation of the central canal of the spinal cord at the tip of the medullary cone. SYN: ventriculus terminalis [TA].

- third v. [TA] a narrow, vertically oriented, irregularly quadrilateral cavity in the midplane, extending from the lamina terminalis to the rostral opening of the mesencephalic aqueduct. This v. communicates at its rostrodorsal corner with each of the two lateral ventricles through the left and right interventricular foramen of Monro. Its narrow roof is formed by the tela choroidea which is attached on either side to the tenia thalami; its lateral wall is formed by the medial surface of the thalamus and, below the hypothalamic sulcus, by the hypothalamus, which also forms its floor. In lateral profile, the third v. exhibits a number of recesses: in its floor, from before backward, 1) the preoptic recess in the acute angle between the base of the lamina terminalis and the dorsum of the optic chiasm, 2) the infundibular recess extending ventrally into the infundibulum but (in humans) not into the hypophysial stalk, and 3) the mamillary or inframamillary recess caused by the protrusion of the mamillary bodies into the v.. From its dorsocaudal corner, the pineal recess extends caudally into the pineal stalk. SYN: ventriculus tertius [TA], v. of diencephalon.

- Verga v. an inconstant, horizontal, slitlike space between the posterior one-third of the corpus callosum and the underlying commissura fornicis (commissura hippocampi; psalterium) resulting from failure of these two commissural plates to fuse completely during fetal development; like the cavity of the septum pellucidum, the space is not a true v. in the sense that it did not develop from the central canal of the neural tube. SYN: cavum psalterii, cavum vergae, sixth v..

- Vieussens v. SYN: cavity of septum pellucidum.

- Wenzel v. SYN: cavity of septum pellucidum.

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ven·tri·cle 'ven-tri-kəl n a cavity of a bodily part or organ: as

a) a chamber of the heart which receives blood from a corresponding atrium and from which blood is forced into the arteries

b) one of the system of communicating cavities in the brain that are continuous with the central canal of the spinal cord, that like it are derived from the medullary canal of the embryo, that are lined with an epithelial ependyma, and that contain a serous fluid see LATERAL VENTRICLE, THIRD VENTRICLE, FOURTH VENTRICLE

c) a fossa or pouch on each side of the larynx between the false vocal cords above and the true vocal cords below

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n.

1. either of the two lower chambers of the heart, which have thick muscular walls. The left ventricle, which is thicker than the right, receives blood from the pulmonary vein via the left atrium and pumps it into the aorta. The right ventricle pumps blood received from the venae cavae (via the right atrium) into the pulmonary artery.

2. one of the four fluid-filled cavities within the brain. The paired first and second ventricles (lateral ventricles), one in each cerebral hemisphere, communicate with the third ventricle in the midline between them. This in turn leads through a narrow channel, the cerebral aqueduct, to the fourth ventricle in the hindbrain, which is continuous with the spinal canal in the centre of the spinal cord. cerebrospinal fluid circulates through all the cavities.

• ventricular adj.

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ven·tri·cle (venґtrĭ-kəl) ventriculus (def. 1).