Paracentral sulcus
Sulcus paracentralis
A short groove on the medial surface of the cerebral hemisphere that marks the front edge of the paracentral lobule.
At a glance
- English
- Paracentral sulcus
- Latin (TA2)
- Sulcus paracentralis
- System
- Brain and spinal cord
- Region
- Head
- Side
- Paired, left and right
About the paracentral sulcus
The paracentral sulcus lies on the medial surface of the hemisphere, the flat face that looks towards the other hemisphere across the longitudinal fissure. It is a short groove that rises from the cingulate sulcus towards the upper border of the hemisphere, a little in front of the point where the central sulcus reaches over onto the medial surface.
Its main job, as a landmark, is to set the front boundary of the paracentral lobule. That lobule is the area of cortex wrapped around the medial end of the central sulcus. In front of the paracentral sulcus lies the medial frontal gyrus, the medial face of the superior frontal gyrus. Behind the lobule lies the marginal branch of the cingulate sulcus, which turns up to the upper border of the hemisphere and separates the paracentral lobule from the precuneus. Below, the cingulate sulcus separates the lobule from the cingulate gyrus. The paracentral sulcus is often small and may appear as a simple notch or a branch arising from the cingulate sulcus.
The paracentral lobule continues the precentral and postcentral gyri onto the medial surface. Its front part is primary motor cortex and its back part is primary somatosensory cortex for the opposite leg and foot. The paracentral sulcus therefore lies just ahead of the motor representation of the lower limb, near the supplementary motor area of the medial frontal cortex.
The region is supplied by branches of the anterior cerebral artery. A stroke in that territory, or a tumour such as a meningioma growing from the falx beside the paracentral lobule, typically causes weakness and loss of sensation in the opposite leg, and may affect control of the bladder.
Function and supply
- Function
- A surface landmark; it bounds the front of the paracentral lobule, which holds the motor and sensory cortex for the opposite leg and foot.
- Blood supply
- Branches of the anterior cerebral artery, mainly its paracentral and callosomarginal branches.
Anthromica
See the paracentral sulcus where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
