FISSURE 



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FISSURE 



Transverse {of the brain). F., Cerebral, Inferior. 

 See F. , Transverse, Inferior. F., Cerebral, Small. 

 See F., Transverse, Inferior. F., Cerebral, Trans- 

 verse. See F., Transverse [of brain). F., Cervical, 

 a congenital cleft in the cervical region, produced by 

 a failure of union of the visceral clefts. F., Choroidal. 

 See F., Cerebral, Transverse. F., Circuminsular ( of 

 Wilder), the groove surrounding the base of the insula. 

 F. of Clevenger. See F. , Occipital, Inferior. F., 

 Collateral, a fissure on the mesal aspect of the cere- 

 brum between the subcalcarine and subcollateral gyri ; 

 it is collocated with the collateral eminence. F., 

 Collateral, Inferior, in lower animals, a slight de- 

 pression in the spinal cord corresponding to the ventro- 

 lateral fissure in man. F., Collateral, Superior, in 

 lower vertebrates, a groove in the spinal cord corre- 

 sponding to the postero-lateral groove in man. F., 

 Constant (of Wilder), any fissure of the adult cere- 

 brum that is always present in a given species or group. 

 Among the human constant fissures are : Calcarine, 

 callosal, central, collateral, circuminsular, olfactory, 

 hippocampal, Sylvian, transinsular, occipital, orbital, 

 parietal, postcentral, precentral, subfrontal, supertem- 

 poral. F., Coronal (of Owen), on the lateral aspect 

 of the carnivoral cerebrum, the frontal portion of the 

 third arched fissure. F., Cruciate, in nearly all the 

 carnivora, a fissure extending laterad, and forming, 

 with its opposite, a Roman cross with the intercerebral 

 fissure. F., Dentate. See F. , Hippocampal. F., 

 Dorsal, in embryology, the dorsal median fissure 

 of the spinal cord. F. of the Ductus venosus, a 

 fissure of the fetal liver, lodging the ductus venosus. 

 It is indistinct in the adult. F. of Ecker. See F. , 

 Occipital, Transverse. F., Ectoccipital (of Owen) , an 

 illy-defined transverse fissure near the tip of the occipital 

 lobe of the brain. F., Ectofrontal (of Owen), a. 

 fissure corresponding in position with the anterior 

 fissure of Sylvius. F., Ectorrhinal (of Owen), a 

 furrow just laterad of the base of the olfactory crus. 

 F., Ectosylvian (of Owen), in Carnivora, the first or 

 lowest arched fissure. F., Ectotentorial (of Owen), 

 the outer fissure on the ventral surface of the occipital 

 lobe. F., Endomesognathica, an occasional fissure 

 in the superior maxilla, between the endognathion and 

 mesognathion. F. , Entoccipital (of Owen) , an illy- 

 defined fissure on the occipital lobe. F., Entolamb- 

 doid. See F, Adoccipital. F., Entorbital (of 

 Owen), an inconstant fissure between the olfactory and 

 orbital fissures. F., Entorrhinal. See F, Ector- 

 rhinal. F., Entotentorial. See F. , Ectotentorial. 

 F., Episylvian (of Wilder), an inconstant dorsal 

 branch of the Sylvian fissure. F., Ethmoid, the 

 superior meatus of the nares. F., Exoccipital (of 

 Wilder), the ape-fissure, a. v. F., Falcial (of Oiven), 

 a fissure on the mesal surface of the frontal lobe. 

 F., Fetal, Ocular, in the embryonic eye, a fissure in 

 the thick wall surrounding the lens. A coloboma re- 

 sults if it be not closed. F., Fimbrial, a small and 

 constant depression between the fasciola and the fim- 

 bria. F., Frontal (of Owen), the precentral and 

 supercentral fissures of man. F., Frontal, First. 

 See F. , Frontal, Supetior. F., Frontal, Inferior, 

 the subfrontal fissure. F., Frontal, Superior, the 

 superfrontal fissure. F., Frontal, Vertical. See F. 

 of Rolando. F., Fronto-marginal, an inconstant 

 fissure in the fronto-marginal convolution. F. for the 

 Gall-bladder, a shallow depression on the lower sur- 

 face of the right lobe of the liver for the accommoda- 

 tion of the gall-bladder. F. of Glaser. See F. of 

 Glaserins. F. of Glaserius, a small fissure in the 

 outer wall of the tympanic cavity opening into the 

 glenoid fossa. It lodges the processus gracilis of the 



malleus, and transmits the laxator tympani muscle 

 and the anterior tympanic artery. F., Glenoid. See 

 F. of Glaserius. F., Hippocampal, a constant fissure 

 of the cerebrum extending from the splenium to near 

 the tip of the temporal lobe ; it is collocated with the 

 hippocamp. F., Horizontal. See F. , Calcarine. F., 

 Horizontal, Great (of brain). See F., Calcarine. F., 

 Hyposylvian (of Wilder) , an inconstant ventral branch 

 of the fissure of Sylvius. F., Incisor, a fissure separat- 

 ing the intermaxillary bone from the superior maxi 11k. 

 F., Infero-lateral. See F, Calcarine. F., In- 

 flected, an inconstant indentation of the dorsal margin 

 of the cerebrum, a little cephalad of the central 

 fissure. F., Infra-orbital. See F, Suborbital, 

 and F. , Spheno-maxillary . F., Insular (of Wilder), 

 one of the fissures crossing the insula. F., Intra- 

 gyral (of Wilder), a small cerebral fissure occasion- 

 ally developed between the larger fissures. F., 

 Intra-orbital, in the dog's brain, a fissure between 

 the olfactory bulb and the supraorbital fissure. F., 

 Intraparietal. See F, Parietal. F., Intrapara- 

 central (of Wilder), a nearly constant depression 

 in the paracentral gyrus. F., Intercerebral (of 

 Wilder) , the great longitudinal fissure of the brain. 

 F., Intergyral (of Wilder), a fissure between two 

 cerebral gyri. F., Interhemispheral. See F., 

 Longitudinal, Great (of brain). F., Interhemis- 

 pheric. See F., Longitudinal, Great (of brain). F., 

 Interlamellar, one of the fissures separating the la- 

 mellae of the cerebellum. F., Interlobar (of Wilder), 

 the fissures of the brain separating the lobes. F., 

 Interlobular, the great longitudinal fissure of the 

 cerebrum. F., Interlobular, Great. See F. of 

 Sylvius. F., Intermedial (of Jensen), an inconstant 

 fissure near the end of the fissure of Sylvius. F., 

 Interpalpebral. See F., Palpebral. F. Interparie- 

 tal. See F., Parietal. F., Interpeduncular, the 

 depression between the crura cerebrit F., of Jensen. 

 See F., Intermedial. F., Lambdoid. I (ofOroen), 

 the occipital fissure, a. v. ; 2 (of Wilder), in the 

 fetus, between the third and seventh months, a sharply 

 defined transverse depression in the occipital lobe, 

 collocated with the lambdoid suture. F., Lateral, a 

 straight fissure between the suprasylvian and the 

 longitudinal fissures. F., Lateral (of Owen), an 

 inconstant fissure on the mesal surface of the frontal 

 lobe. F., Lateral (of spinal cord). See F. , 

 Antero-lateral. F., Lateral, Posterior (of spinal 

 cord). See F., Postero-lateral. F., Limbic (of 

 Broca), the fissure surrounding Broca's great limbic 

 lobe. It includes the supercallosal, precuneal . and part 

 of the collateral fissures. F., Longitudinal (of brain ). 

 See F. , Longitudinal, Great (of drain) . F., Longitu- 

 dinal (of liver), a deep fissure on the under surface of tin- 

 liver, separating the right and left lobes. F., Longi- 

 tudinal, Great (of brain), the deep mesal fissure that 

 divides the cerebrum into two hemispheres. F., 

 Longitudinal, Medilateral. See F. , Intercerebral. 

 F., Longitudinal, Posterior (of spinal cord), a deep, 

 narrow groove, extending the whole length of the 

 spinal cord, in the middle line posteriorly. F., 

 Longitudinal, Superior. See F. , Intercerebral. F., 

 Marginal (of Owen), a fissure on the mesal surface of 

 the cerebrum, forming the cephalic boundary of the 

 paracentral convolutions. F., Maxillary, a fissure on 

 the internal surface of the superior maxilla for the 

 maxillary process of the palate bone. It extends 

 obliquely downward and forward from the lower por- 

 tion of the orifice of the antrum. F., Medial, a fis- 

 sure parallel with and posterior to the fissure of Ro- 

 lando. F., Median, Posterior (of spinal cord). See 

 F, Longitudinal, Posterior (of spinal cord). F., Me- 



