Origin on the sagittal crest for about one centimeter craniad of the interparietal bone. The muscle passes laterad onto the surface of the auricle and is inserted into the auricular cartilage a little caudad of the middle of its convex surface. At its lateral end the cranial margin is closely united to the under surface of the levator auris longus (g).
Relations.—Outer surface at the medial end with the epicranius (h), the abductor auris longus (m), and levator auris longus (g); at the lateral end with the skin. Inner surface with the temporal muscle (n) and the auricular cartilage.
Action.—Pulls the external ear dorsad.
M. abductor auris longus ([Fig. 63], m; [Fig. 64], q). (Part of the auricularis posterior of man.)
Origin on the sagittal crest dorsad of the interparietal bone, caudad of that of the auricularis superior (k), which it partly covers.
The muscle passes laterad as a flat band 8 to 10 millimeters wide over the caudal surface of the concha of the ear, and is inserted ([Fig. 64], q) on the lateral surface of the eminentia conchæ, caudad of the antitragus.
Relations.—Outer surface with the levator auris longus (g) and the integument. Inner surface with the auricularis superior (k), the abductor auris brevis (l), and the concha.
Action.—Pulls the external ear caudad.
M. abductor auris brevis ([Fig. 63], l).
Origin by a tendon from the lambdoidal crest for one or two centimeters laterad of the middle.