Anatomy of the Cat

by Jacob Reighard; H. S. Jennings

Origin on the ligament which connects the zygomatic process of the frontal with the frontal process of the malar. The fibres form a thin band about 7 millimeters wide which passes craniad, closely united to the inner surface of the frontoscutularis. At the caudal edge of the zygomaticus (d) the muscle is interrupted by a short tendinous interval; the fibres then continue to their insertion on the tip of the antitragus.

Relations.—Outer surface with the frontoscutularis, the zygomaticus (d), and the integument. Inner surface with the temporal muscle and M. antitragicus (n).

Action.—Pulls the ear craniodorsad.

The remainder of the muscles of the ear, which, with the exception of the tragicus lateralis, merely interconnect the cartilages of the external ear or parts of these cartilages, are [described] in connection with the account of the Auditory Organ.

Owing to the presence of the fibrous pad to which the whiskers are attached, the facial muscles between the eye and the mouth differ in the cat in some respects from those of related animals. This fibrous pad interrupts the muscles, frequently breaking muscles which are elsewhere single into two.

M. zygomaticus minor, or malaris ([Fig. 64], e).—This muscle is not always present; when it exists it forms a very thin flat band of fibres passing from the ventral side of the eye toward the angle of the mouth.

Origin among the fibres of the orbicularis oculi (s) in the lower eyelid. The fibres pass ventrad; the insertion varies. In some specimens the insertion is among the fibres of the orbicularis oris (i), at the angle of the mouth, beneath the zygomaticus (d). In other cases this muscle is said to be inserted into the pad on which the whiskers rest.

Relations.—Outer surface with the integument and near its insertion with the zygomaticus major (d). Inner surface with the malar bone and the masseter muscle.

Action.—Pulls the angle of the mouth (or the whiskers) dorsad.

M. orbicularis oris ([Fig. 64], i).—This forms a very thin layer of subcutaneous concentric fibres which surround the mouth, that of the upper lip being thicker than that of the lower lip. The part of the muscle in the lower lip has its fibres intermingled with those of the platysma (a′). In the median line the fibres of the upper lip are interrupted by a raphe, and caudad of this are intermingled with those of the caninus.