Precentral gyrus (located immediately to the central sulcus), covers much of the primary somatomotor cortex and anterior paracentral gyrus covers the medial continuity of primary somatomotor cortex, both being involved in motor control, because they contain neurons (giant pyramidal neurons-of Betz's belonging to layer V) involved in muscle control.
The face is represented in the first one third of the lateral precentral gyrus, the upper extremity (arm, forearm and hand especially), is represented in the second third of the lateral precentral gyrus, and the trunk is represented in the third third (medial) of the precentral gyrus; the hip is represented in the place where precentral gyrus is continuing with paracentral gyrus and the lower limb (thigh, leg and foot), is represented in anterior paracentral gyrus (fig.
