| sixth ventricle | 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 foetal development; like the cavity of the septum pellucidum, the space is not a true ventricle in the sense that it did not develop from the central canal of the neural tube. Synonym: cavum psalterii, cavum vergae, sixth ventricle. (05 Mar 2000) |
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| skeletal muscle ventricle | Autologous skeletal muscle that is wrapped around the heart and electrically stimulated in order to provide mechanical heart assistance. The latissimus dorsi muscle is commonly used to form this ventricle that functions to independently augment cardiac performance by pumping in series with the heart. (12 Dec 1998) |
| hypoplasia of right ventricle | Failure of development of the right ventricle resulting in its having little muscle and much connective tissue instead of the reverse. (05 Mar 2000) |
| slit ventricle syndrome | <syndrome> In shunt dependent patients, a state characterised by intermittent or chronic headaches, small ventricles, and slow reflux of the valve mechanism. (05 Mar 2000) |
| sylvian ventricle | A slitlike, fluid-filled space of variable width between the left and right transparent septum, which occurs in less than 10% of human brains and may communicate with the third ventricle. Synonym: cavum septi pellucidi, Duncan's ventricle, fifth ventricle, pseudocele, pseudoventricle, sylvian ventricle, ventricle of Sylvius, ventriculus quintus, Vieussens' ventricle, Wenzel's ventricle. (05 Mar 2000) |
| double outlet right ventricle | <cardiology, embryology> Incomplete transposition of the great vessels in which both the aorta and the pulmonary artery arise from the right ventricle, often associated with a subaortic ventricular septal defect. (12 Dec 1998) |
| Duncan's ventricle | A slitlike, fluid-filled space of variable width between the left and right transparent septum, which occurs in less than 10% of human brains and may communicate with the third ventricle. Synonym: cavum septi pellucidi, Duncan's ventricle, fifth ventricle, pseudocele, pseudoventricle, sylvian ventricle, ventricle of Sylvius, ventriculus quintus, Vieussens' ventricle, Wenzel's ventricle. (05 Mar 2000) |
| ischemic contracture of the left ventricle | Irreversible contraction of the left ventricle of the heart as a complication seen in the early period of cardiopulmonary bypass and now avoided by appropriate cardioplegic solutions. Synonym: myocardial rigor mortis, stone heart. (05 Mar 2000) |
| tenia of fourth ventricle | The line of attachment of the choroid roof to the rim of the fourth ventricle. Synonym: tenia of fourth ventricle. (05 Mar 2000) |
| terminal ventricle | A dilation of the central canal of the spinal cord at the tip of the medullary cone. Synonym: ventriculus terminalis. (05 Mar 2000) |
| third ventricle | A narrow, vertically oriented, irregularly quadrilateral cavity in the midplane, extending from the lamina terminalis to the rostral opening of the mesencephalic aqueduct. This ventricle 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 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 ventricle 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 ventricle. From its dorsocaudal corner, the pineal recess extends caudally into the pineal stalk. Synonym: ventriculus tertius, diacele, ventricle of diencephalon. (05 Mar 2000) |
| fifth ventricle | A slitlike, fluid-filled space of variable width between the left and right transparent septum, which occurs in less than 10% of human brains and may communicate with the third ventricle. Synonym: cavum septi pellucidi, Duncan's ventricle, fifth ventricle, pseudocele, pseudoventricle, sylvian ventricle, ventricle of Sylvius, ventriculus quintus, Vieussens' ventricle, Wenzel's ventricle. (05 Mar 2000) |
| laryngeal ventricle | The recess in each lateral wall of the larynx between the vestibular and vocal folds and into which the layrngeal sacculus opens. Synonym: ventriculus laryngis, laryngeal sinus, Morgagni's sinus, Morgagni's ventricle, sinus laryngeus. (05 Mar 2000) |
| fourth ventricle | 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 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 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. Synonym: ventriculus quartus, ventricle of rhombencephalon. (05 Mar 2000) |
| fourth ventricle mass | <radiology> IN ADULTS: choroid plexus papilloma, haemangioblastoma, vermian metastasis, arteriovenous malformation (AVM), inflammatory mass/cyst IN KIDS: medulloblastoma, uniform enhancement, homogeneous, ependymoma, patchy enhancement, heterogeneous, calcified (12 Dec 1998) |