shape of the lung each lung is pyramidal in shape with the base situated inferiorly and the apex superiorly the body of the lungs are “C” shaped in the axial plane with the right “C” being forward facing and the left “C” being backward facing the hilum is concave the inner surface contains a smooth line while the acini are reminiscent of bunches of grape that take origin from the tree like pattern of the tracheobronchial tree the external surface is smooth