[Location]
area 4 , ant. wall of the central sulcus and adjacent portions of precentral gyrus.

[Histological structure]
agranular, giant pyramidal cells of Betz.

[Lesion]
* causes varying degrees of paralysis of the represented muscles.
* loses voluntary control of discrete movements of the distal segments of the limbs, the hands and fingers.
* ability to comtrol the fine movements is gone.