The anterior portion of the paracentral lobule is part of the frontal lobe and contains a little portion of Brodmann's area 6 (SMA): this is because the paracentral sulcus (branch of the cingulate sulcus) does not correspond to the precentral sulcus on the medial plane.
The posterior portion is considered part of the parietal lobe and deals with somatosensory of the distal limbs.
While the boundary between the lobes, the central sulcus, is easy to locate on the lateral surface of the cerebral hemispheres, this boundary is often discerned in a cytoarchetectonic manner in cases where the central sulcus is not visible on the medial surface.
Function
Neurons in paracentral lobule are concerned with:
Motor and sensory innervations of the contralateral lower extremity
Regulation of physiological function such as blushing,[1] defecation and micturition