fissure
[fish´er] 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.
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.
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.
palpebral fissure the longitudinal opening between the eyelids.
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.
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.
transverse fissure 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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
lat·er·al sul·cus
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.
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