pl. sulci [L., groove]
A furrow, groove, or fissure, esp. on the surface of the brain.
The space in the floor of the mouth between the base of the tongue and the alveolar ridge, on each side extending from the frenum of the tongue back to the retromolar wall.
On the medial side of each cerebral hemisphere, the groove that runs parallel to the top of the corpus callosum, separating the corpus callosum from the overlying cingulate gyrus.
The groove that runs down the side of the cerebral hemisphere and separates the parietal and frontal lobes. The central sulcus lies approx. midway along the lateral surface of the cerebral hemisphere, between the frontal and occipital poles of the brain. The gyrus anterior to the central sulcus -- the precentral gyrus -- is the primary motor cortex, and the gyrus posterior to the central sulcus -- the postcentral gyrus -- is the primary sensory cortex. Occasionally, the central sulcus is interrupted and is not a continuous groove from top to bottom.
SYN: sulcus centralis
SEE: Central sulcus.
A groove curving transversely along the anterior medial surface of the cerebral hemisphere, which parallels the callosal sulcus, from which it is separated by the cingulate gyrus. The cingulate sulcus forms the lower edge of the medial frontal gyrus and the paracentral lobule.
The groove that almost entirely encircles the insula, a section of cerebral cortex that lies hidden in the floor of the Sylvian fissure.
A groove running longitudinally on the inferior (under) surfaces of the occipital and temporal lobes of the brain. In the occipital lobe, the collateral sulcus forms the lower edge of the lingual gyrus; in the temporal lobe, it forms the lower edge of the posterior two-thirds of the parahippocampal gyrus.
The ridges on the skin of the palmar surface of the fingers and toes, which form the fingerprints.
The inferior or the superior frontal sulcus.
The crevice between the free gingiva and the tooth surface. A healthy sulcus produces gingival sulcular fluid (GSF), which helps to remove bacteria from the sulcus. Normal sulcus depth is 0.5-1.5 mm. Inflammation in the sulcus is the first sign of gingivitis. When enlarged by disease, the gingival sulcus deepens and becomes a periodontal pocket.
A transverse groove along the inside of each lateral wall of the third ventricle of the brain. The sulcus runs from the interventricular foramen back to the cerebral aqueduct, and it marks the boundary of the thalamic nuclei (dorsally) and the hypothalamic nuclei (ventrally).
inferior frontal sulcus
A groove running from front to back along the lateral surface of the frontal lobe of the brain, separating the middle frontal gyrus from the inferior frontal gyrus.
inferior temporal sulcus
A groove that runs from front to back along the lower lateral surface of the temporal lobe of the brain. It runs under and parallel to the superior temporal sulcus, from which it is separated by the middle temporal gyrus. The inferior temporal sulcus is usually interrupted and not a continuous groove.
A groove branching from the postcentral sulcus and running transversely and posteriorly along the lateral surface of the parietal lobe of the brain. It divides the posterior portion of the parietal lobe into two parts, the superior and the inferior parietal lobules.
SEE: Sylvian fissure.
lateral occipital sulcus
A short transverse groove on the lower lateral surface of the occipital lobe of the brain. It separates the superior and the inferior occipital gyri.
A shallow groove running transversely halfway down each inner wall of the neural tube of the embryo. It divides the alar (dorsal, sensory precursor) neural tube cells from the basal (ventral, motor precursor) neural tube cells.
SEE: Malleolar groove.
On the dorsal surface of the tongue, the midline groove that separates the surface into right and left halves.
Groove on the lateral wall of the third ventricle from the opening to the lateral ventricle to the opening of the cerebral aqueduct of the brain.
The depression between the caruncula of the hymen and the labium minus.
Trench between the labium minus and the hymen on either side.
The lateral or the transverse occipital sulcus.
A groove running longitudinally on the inferior (under) surface of the temporal lobe of the brain. It is parallel to the collateral sulcus, from which it is separated by the medial occipitotemporal gyrus.
The most medial groove running longitudinally (rostrocaudally) on the orbital surface of the frontal lobe of the brain, separating the gyrus rectus from the medial orbital gyrus. The olfactory bulb and olfactory tract lie along the olfactory sulcus.
olfactory nasal sulcus
An anterior-posterior groove in the wall of the nasal cavity. It passes from the anterior area to the lamina cribrosa.
SYN: nasal carina
An oblique groove on the medial surface of the brain, marking the boundary between the parietal and the occipital lobes. The calcarine fissure intersects the middle of the parieto-occipital sulcus.
The groove that runs down the lateral surface of the parietal lobe of the brain, parallel to the central sulcus. Between the central and the postcentral sulci lies the postcentral gyrus, which is the primary sensory cortex.
The groove that runs down the lateral surface of the frontal lobe of the brain, parallel to the central sulcus. Between the precentral and the central sulci lies the precentral gyrus, which is the primary motor cortex. The precentral sulcus is usually interrupted and not a continuous groove.
An interrupted sulcus generally parallel with the fissure of Rolando and anterior to it.
A furrow for the posterior lung adjacent to the bodies of the thoracic vertebrae.
SEE: Sagittal fissure.
sulcus spiralis cochleae
A groove between the labium tympanicum and labium vestibulare.
A groove that continues the path of the cingulate sulcus posteriorly, although the subparietal and the cingulate sulci are not directly connected.
superior frontal sulcus
A groove running from front to back along the upper surface of the frontal lobe of the brain, separating the superior frontal gyrus from the middle frontal gyrus.
superior temporal sulcus
A groove that runs from front to back along the lateral surface of the temporal lobe of the brain. It runs under and parallel to the Sylvian fissure, from which it is separated by the superior temporal gyrus.
The superior or the inferior temporal sulcus.
1. A shallow groove along the outside surface of the right atrium of the heart marking the junction of the venae cava and the atrium. The crista terminalis is found at the corresponding location inside the right atrium.
2. A V-shaped groove on the dorsal surface of the tongue separating the anterior two-thirds of the tongue from the posterior one-third. The anterior (oral) part of the tongue receives different innervation and has different embryological origins from the posterior (pharyngeal) part.
transverse occipital sulcus
A groove running transversely along the lateral surface of the occipital lobe of the brain. The intraparietal sulcus deadends into the midpoint of the transverse occipital sulcus.