| 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) |
| lateral recess of fourth ventricle | The narrow recess of the ventricle that extends laterally over, and down along the side of, the inferior cerebellar peduncle and the overlying cochlear nuclei; at its tip it opens by way of Luschka's foramen into the interopeduncular cistern of the subarachnoid space. By way of this recess, part of the choroid plexus of the fourth ventricle protrudes into the subarachnoid space. Synonym: recessus lateralis ventriculi quarti. (05 Mar 2000) |
| lateral vein of lateral ventricle | A vein draining deep portions of the temporal and parietal lobes; it runs in the lateral wall of the lateral ventricle to terminate in the superior thalamostriate vein. Synonym: vena ventriculi lateralis lateralis, lateral atrial vein, lateral vein of lateral ventricle. (05 Mar 2000) |
| lateral ventricle | A cavity shaped somewhat like a horseshoe in conformity with the general shape of the hemisphere; each lateral ventricle communicates with the third ventricle 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 or cella media 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 ventricle invades the cella media and the inferior horn (but not the anterior and posterior horn) from the medial side. Synonym: ventriculus lateralis, ventricle of cerebral hemisphere. (05 Mar 2000) |
| left ventricle | <anatomy> The muscular chamber of the heart which accepts blood from the left atrium and ejects it into the aorta to the systemic circulation. (27 Sep 1997) |
| anterior cerebral artery | <anatomy, artery> One of the two terminal branches (with middle cerebral artery) of the internal carotid; it passes anterior, loops around the genu of the corpus callosum then posteriorly in the interhemispheric fissure along with its fellow of the opposite side, the two being joined by the anterior communicating artery; for descriptive purposes it is divided into two parts: the precommunical part (A2 segment of clinical terminology), supplying branches to the thalamus and corpus striatum, and the postcommunical part, (A2) or pericallosal artery, supplying branches to the cortex of the medial parts of the frontal and parietal lobes. Synonym: arteria cerebri anterior. (05 Mar 2000) |
| anterior cerebral vein | <anatomy, vein> A small vein that parallels the anterior cerebral artery and drains into the basal vein. Synonym: vena cerebri anterior. (05 Mar 2000) |
| arteries of cerebral haemorrhage | Numerous small branches from the sphenoidal part of the middle cerebral arteries supplying the lateral and anterior parts of the corpus striatum. Synonym: arteriae centrales anterolaterales, arteriae thalamostriatae anterolaterales, anterolateral central arteries, anterolateral striate arteries, anterolateral thalamostriate arteries, arteries of cerebral haemorrhage, lenticulostriate arteries. (05 Mar 2000) |
| ganglionic layer of cerebral cortex | Layer 5 of the cortex cerebri. (05 Mar 2000) |
| malaria, cerebral | A condition that is most commonly seen as a severe complication of malaria, falciparum mainly involving the brain. It has also been reported to occur as a result of infection with other plasmodium species. This disease is often fatal and presents as disturbances in consciousness ranging from somnolence to coma, major motor seizures, and organic psychosis. The onset may be gradual or sudden following a convulsion. (12 Dec 1998) |
| paroxysmal cerebral dysrhythmia | A diffusely abnormal electroencephalogram often seen with epilepsy. (05 Mar 2000) |
| medial cerebral surface | It faces, above as well as anterior and posterior to the corpus callosum, the falx cerebri; below it are the mesencephalon and the dura-covered medial wall of the middle cranial fossa. Synonym: facies medialis cerebri, medial cerebral surface. (05 Mar 2000) |
| medial surface of cerebral hemisphere | It faces, above as well as anterior and posterior to the corpus callosum, the falx cerebri; below it are the mesencephalon and the dura-covered medial wall of the middle cranial fossa. Synonym: facies medialis cerebri, medial cerebral surface. (05 Mar 2000) |
| cerebral | <anatomy> Of or pertaining of the cerebrum or the brain. (18 Nov 1997) |