Paracentral lobule

The paracentral lobule is a U-shaped gyrus located on the inner side of the cerebral hemisphere.

This lobule is formed by the extensions of two gyri, namely the precentral and postcentral gyri, located primarily on the outer surface of the cerebral hemisphere. The paracentral lobule consists of two parts: the anterior part, which is an extension of the precentral gyrus, belongs to the frontal lobe and is responsible for controlling the leg region as the primary motor area. It may also include the supplementary motor regions and the cortical control center for defecation and micturition. The posterior part, an extension of the postcentral gyrus, belongs to the parietal lobe and serves as the primary sensory area for the leg region.

The paracentral lobule surrounds the central sulcus as it extends to the inner side. On the inner side, the precentral sulcus forms the front boundary of the paracentral lobule, known as the paracentral sulcus, separating it from the medial frontal gyrus. Similarly, the postcentral sulcus extends to the inner side, forming the back boundary of the paracentral lobule, called the marginal sulcus. This marginal sulcus, which is essentially the upward extension of the cingulate sulcus, separates the paracentral lobule from the pre-cuneus at its back.

Blood supply to the paracentral lobule region is provided by the anterior cerebral artery.