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1. a narrow slit or cleft, especially one of the deeper or more constant furrows separating the gyri of the brain.
2. a deep cleft in the surface of a tooth, usually due to imperfect fusion of the enamel of the adjoining dental lobes. It can be treated with a dental sealant to decrease risk of caries.
abdominal fissure a congenital cleft in the abdominal wall; see also gastroschisis and thoracoceloschisis. Called also celoschisis.
anal fissure (fissure in ano) a painful lineal ulcer at the margin of the anus.
anterior median fissure a longitudinal furrow along the midline of the ventral surface of the spinal cord and medulla oblongata.
fissure of Bichat transverse fissure (def. 2).
branchial fissure pharyngeal groove.
central fissure fissure of Rolando.
collateral fissure a longitudinal fissure on the inferior surface of the cerebral hemisphere between the fusiform gyrus and the hippocampal gyrus.
Henle's f's spaces filled with connective tissue between the muscular fibers of the heart.
hippocampal fissure one extending from the splenium of the corpus callosum almost to the tip of the temporal lobe; called also hippocampal sulcus.
longitudinal fissure the deep fissure between the two cerebral hemispheres.
palpebral fissure the longitudinal opening between the eyelids.
portal fissure porta hepatis.
posterior median fissure
1. a shallow vertical groove in the closed part of the medulla oblongata, continuous with the posterior median fissure of the spinal cord.
2. a shallow vertical groove dividing the spinal cord throughout its length in the midline posteriorly; called also posterior median sulcus.
presylvian fissure the anterior branch of the fissure of Sylvius.
pudendal fissure rima pudendi.
Rolando's fissure (fissure of Rolando) a groove running obliquely across the superolateral surface of a cerebral hemisphere, separating the frontal lobe from the parietal lobe. Called also central fissure and central sulcus.
fissure of round ligament one on the visceral surface of the liver, lodging the round ligament in the adult.
sylvian fissure (fissure of Sylvius) one extending laterally between the temporal and frontal lobes, and turning posteriorly between the temporal and parietal lobes.
1. porta hepatis.
2. the transverse cerebral fissure between the diencephalon and the cerebral hemispheres; called also fissure of Bichat.
zygal fissure any of the fissures on the cerebral cortex that consist of two branches connected by a stem.
deepest and most prominent of the cortical sulci, extending from the anterior perforated substance first laterally at the deep incisure between the frontal and temporal lobes, then caudal and slightly posterior over the lateral aspect of the cerebral hemisphere; the superior temporal gyrus forms its lower bank, the insula its greatly expanded floor, and the frontal and parietal opercula its upper bank. The sulcus is composed of three portions, a large posterior ramus [TA] (ramus posterior [TA]) that is commonly called the lateral sulcus, a short anterior ramus [TA] (ramus posterior [TA]) located between the pars orbitalis and pars triangularis of the inferior frontal gyrus, and a short ascending ramus [TA] (ramus ascendens [TA]) located between the pars triangularis and pars opercularis.
The deepest and most conspicuous of the cortical fissures of the brain, extending between the frontal and temporal lobes, then back and slightly upward over the lateral aspect of the cerebral hemisphere. Also called fissure of Sylvius, lateral sulcus.
Sylvius,Franciscus, Dutch physician, 1614-1672.
aqueduct of Sylvius
fossa of Sylvius
sylvian fissure - Synonym(s): lateral cerebral sulcus
sylvian valve - Synonym(s): valve of inferior vena cava
sylvian ventricle - Synonym(s): cavity of septum pellucidum