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Etymology: L, orbita, wheel track, fissura, cleft
the space between the floor and lateral wall of the orbit, serving as a conduit for nerves and blood vessels.
1. a narrow slit or cleft, especially one of the deeper or more constant furrows separating the gyri of the brain.
2. in dermatology a deep crack in the skin, often through a scab, which penetrates into the subcutis.
a congenital cleft in the abdominal wall.
anal fissure, fissure in ano
a painful linear ulcer at the margin of the anus.
fissure of Bichat
transverse fissure (2).
fissure of Rolando.
a longitudinal fissure on the ventral surface of the cerebral hemisphere between the fusiform gyrus and the hippocampal gyrus.
dorsal median fissure
1. a shallow vertical groove in the closed part of the medulla oblongata, continuous with the dorsal median sulcus of the spinal cord.
2. a shallow vertical groove dividing the spinal cord throughout its whole length in the midline dorsally. Called also dorsal median sulcus.
a split in the margin of the pinna which can gradually become larger from continued trauma.
one extending from the splenium of the corpus callosum almost to the tip of the temporal lobe; called also hippocampal sulcus.
the fissure between the two cerebral hemispheres in birds.
fissure between the two incisive bones at the rostral end of the pig's face.
the dorsal laryngeal furrow.
ligamentum teres fissure
on the diaphragmatic surface of the liver; houses the ligamentum teres.
in radiology, the variation in radiodensity indicating the division between lobes of the lung.
the deep fissure between the cerebral hemispheres.
an enlarged palpebral fissure.
a ventral fissure in the developing optic cup through which blood vessels pass to the enclosed mesenchyme.
see orbital foramen.
a pair of fissures perforating the rostral extremity of the palate.
the opening between the eyelids.
see perianal fistula.
the chorda tympani, on its way to merge with the lingual branch of the mandibular nerve, passes across the tympanic cavity and emerges at the petrotympanic fissure.
the ventral branch of the fissure of Sylvius.
mediastinal fluid dissects into fissures between lung lobes causing fissure lines on radiographs to appear wide centrally and narrower peripherally.
Rolando's fissure, fissure of Rolando
a groove running obliquely across the superolateral surface of the cerebral hemisphere, separating the frontal from the parietal lobe. Called also central fissure and central sulcus.
round ligament fissure
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 dorsally between the temporal and parietal lobes of the brain.
1. porta hepatis.
2. the transverse cerebral fissure between the diencephalon and the cerebral hemispheres; called also fissure of Bichat.
on the ventral surface of the skull, near the confluence of the osseous bulla and the occipital bone, this pair of fissures serve as conduits for the glossopharyngeal, vagal and accessory nerves in species without a jugular foramen.
ventral median fissure
a longitudinal furrow along the midline of the ventral surface of the spinal cord and medulla oblongata.
a cerebral fissure consisting of two branches connected by a stem.