The central sulcus is the deep groove that crosses the side of each cerebral hemisphere between the precentral gyrus in front and the postcentral gyrus behind. It separates the frontal lobe from the parietal lobe, and the primary motor cortex from the primary somatosensory cortex. [1][2]
The 3D brain needs JavaScript. The text below still says where the central sulcus is and what it does.
Seen from the left and above: the precentral gyrus is lit in blue, the postcentral gyrus in orange, on both hemispheres. The groove runs where blue meets orange; the top (axial) slice button cuts across it. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
A groove has no shape of its own; lit: the parts on either side of it. Lit: in front, the precentral gyrus in blue; behind, the postcentral gyrus in orange. A sulcus is the groove between two gyri; the central sulcus runs between the precentral gyrus in front and the postcentral gyrus behind, and so marks the border of the frontal and parietal lobes. [2][1]
Where it is
Above the lateral sulcus lie the frontal and parietal lobes, which are separated from each other by the central sulcus: the frontal lobe in front of it, the parietal lobe behind it. [2]
It forms before birth, at about 22 to 23 weeks of gestation: it begins as a point or short groove near the top of the brain beside the midline, then lengthens down towards the lateral sulcus and up towards the longitudinal fissure. [1]
It is sometimes confused with the longitudinal fissure, the large midline separation between the left and right halves of the cerebrum; the central sulcus instead crosses the side of each half. [1][2]
What it does
It is a landmark rather than a working part: a fold of the cortex whose front bank belongs to the primary motor cortex, which lies on the front wall of the central sulcus and extends onto the precentral gyrus. [4]
Behind it, the postcentral gyrus holds the primary somatosensory cortex, the main area receiving the sense of touch. [5][1]
It is a classic “limiting sulcus”, one that separates two areas with different jobs: here motor from sensory. [6]
A bend in the groove where it passes the hand area of the motor cortex is called the “hand knob”. [1]
Inside it
In the human brain about two-thirds of the folded cortex is buried within sulci, so a large share of the motor and touch cortex sits on the hidden walls of grooves like this one rather than on the visible surface. [6]
Other names
Also called the central fissure, the fissure of Rolando or the Rolandic fissure, after the anatomist Luigi Rolando. [1]
Sulcus or fissure: a sulcus is the groove between two gyri, and deeper furrows that divide the brain into lobes are often called fissures, which is why this groove has both names. [6][2]
Size
The model has no shape for the central sulcus, so the groove itself is not measured here. On the left hemisphere, the stretch where the precentral gyrus and the postcentral gyrus come within 3 mm of each other fits in a box about 53 mm front to back, 58 mm top to bottom and 64 mm side to side (the box that stretch fits in, not the groove’s length along its bends or its depth). [7]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.