Muscle, Cricoarytenoid Posterior (M. Cricoarytenoideus Posterior, Pna, Bna; M. Cricoarytaenoideus Posticus)

Muscle, cricoarytenoid posterior (lat. m. cricoarytenoideus posterior, pna, bna; m. cricoarytaenoideus posticus) - unpaired muscle of the larynx.

It arises from the posterior surface of the cricoid cartilage. It is directed outward and upward, attached to the condyle of the arytenoid cartilage.

The main action of the muscle is to pull the vocal fold back, expanding the glottis. Participates in swallowing and breathing. Innervated by the recurrent laryngeal nerve.

Muscles that perform a special job develop in a special way. When scientist Karl Baer was still working on preserving the anthropological type Homo erectus, who lived in Africa about 1,600 thousand years ago and was known as the “working man” (Archanthropus robustus), he noticed that the upper jaw of this man was strengthened by additional layers of muscles. It would be impossible to secure a stone stick and create digging sticks without strengthening. But even in the modern species of people, the strong jaw structure of the maxillary bone has been evolutionarily fixed due to special working conditions. Most of us are such simple ancient workers. It will be possible to dig up many cubic meters of earth with a shovel or jump from a three-meter cliff, not to mention more difficult work, only with muscles that are strong from birth.

The cricoglossus muscle (carina) is a large transverse muscle of the anterior neck. Located on the inner surface of the cricoid process, at the base of the skull, medial to the horizontal plane dividing the external carotid artery into two branches. It approaches from the front to the arytenoid process, located on the side of the cricoid bone.

The cricoid muscle was located deep at the base of the wing of the tarsus of the signet ring-like paw of birds. In primitive and modern people it is practically not visible in the fork of the sternum skeleton. Adult male sternum