Cricopharyngeal Muscle Under Normal and Pathological Conditions

Cricopharyngeal Myotomy and Arytenoid Adduction in the Management of Combined Laryngeal and Pharyngeal Paralysis

“…However, electromyographic studies in animals and human beings have failed to detect any tonic contraction 10,11. Instead, the cricopharyngeus contracts in response to such stimuli as intraluminal distension, superior laryngeal nerve stimulation, and displacement of the larynx 12,13. Although swallowing does not relax the cricopharyngeus, it does inhibit reflex contraction of this muscle 10,14.…”

Esophageal motility

“…The uppermost portion of the cricoid cartilage may produce an indentation on the anterior wall, commencing at the C 5 to C 6 vertebral level, and the postcricoid venous plexus (375) may be seen as an impression at the lower border of the cricoid cartilage. The posterior wall of the pharynx is smooth in the upper part; however, in the lower part, the circopharyngeus muscle may sometimes form a posterior indentation termed the hypopharyngeal bar at the C 5 to C 7 vertebral level (49, 446, 454, 479). Because of the upward displacement of the cricoid associated with swallowing, the cricopharyngeus is frequently seen obliquely oriented and located below the level of the lower border of the cricoid cartilage (295).…”

“…The relaxation component is due to the cessation of tonic activity in the cricopharyngeal and inferior pharyngeal constrictor muscles, whereas the opening is due to contraction of the suprahyoid muscles. Impaired relaxation of the cricopharyngeus muscle is responsible for the prominent cricopharyngeal bar or cricopharyngeal achalasia (49, 454, 479). In contrast, paralysis of the suprahyoid muscle and lack of opening of the upper esophageal sphincter are responsible for paralytic upper sphincter achalasia.…”