(anatomy) A smooth muscle helping to raise the upper eyelid.

(anatomy) A flat muscle situated under the external oblique muscle in the lateral and ventral part of the abdominal wall, that have aponeuroses extending medially to ensheathe the rectus muscles and fusing in the midventral line in the linea alba, and that act to compress the abdominal contents and to assist in expelling the contents of various visceral organs (as in urination, defecation, parturition, and expiration).

(anatomy) A long thin extraocular muscle that arises just above the margin of the optic foramen, is inserted on the upper part of the eyeball, and moves the eye downward and laterally.

(anatomy) A short extraocular muscle that arises from the orbital surface of the maxilla, is inserted slightly in front of and below the superior oblique muscle, and moves the eye upward and laterally.

(anatomy) A muscle of the larynx that arises from the posterior surface of the lamina of the cricoid cartilage, inserts into the posterior of the process of the arytenoid cartilage, and widens the opening of the vocal cords.

(anatomy) A muscle that arises from the inner surface of the lateral pterygoid plate and from the palatine and maxillary bones, is inserted into the ramus and the gonial angle, cooperates with the masseter and temporalis in elevating the lower jaw, and controls certain lateral and rotary movements of the jaw.

(anatomy) A muscle that arises from the greater wing of the sphenoid bone and from the outer surface of the lateral pterygoid plate, is inserted into the condyle of the mandible and the articular disk of the temporomandibular joint, and acts as an antagonist of the masseter, temporalis, and medial pterygoid muscles.

(anatomy) A muscle arising from the transverse processes of the lower six cervical vertebrae, inserting on the upper surface of the first rib, and functioning to bend the neck forward and laterally and to rotate it to the side.

(anatomy) A muscle arising from the transverse processes of the fourth to sixth cervical vertebrae, inserting on the outer surface of the second rib, and functioning to raise the second rib and to bend and slightly rotate the neck.

(anatomy) A muscle arising from the transverse processes of the third to sixth cervical vertebrae, inserting on the scalene tubercle of the first rib, and functioning to bend the neck forward and laterally and to rotate it to the side.