Corpus: Middle pharyngeal constrictor muscle: Unterschied zwischen den Versionen

The middle pharyngeal constrictor muscle is a striated skeletal muscle, positioned as the middle of the three pharyngeal constrictors. It is joined cranially by the superior pharyngeal constrictor muscle and caudally by the inferior pharyngeal constrictor muscle.

The middle pharyngeal constrictor muscle primarily develops from the muscle system of the 4th pharyngeal (gill) arch.

Classification

The middle pharyngeal constrictor muscle consists of two parts:

• the pars chondropharyngea
• the pars ceratopharyngea.

Origin

The pars chondropharyngea originates from the lesser horn (cornu minus) of the hyoid bone, while the pars ceratopharyngea originates from the greater horn (cornu majus) of the hyoid bone.

Attachment

The fibers of the middle pharyngeal constrictor muscle extend obliquely upward, medially, and dorsally, merging with the fibers from the opposite side at the pharyngeal raphe. These fibers overlap the caudal fibers of the superior pharyngeal constrictor muscle in a manner similar to roof tiles.

The middle pharyngeal constrictor muscle is innervated by the pharyngeal plexus, which includes contributions from the glossopharyngeal nerve (cranial nerve IX) and the vagus nerve (cranial nerve X).

Swallowing

The middle pharyngeal constrictor muscle contracts to constrict the oropharynx (pars oralis pharyngis), pushing the food bolus towards the esophagus during swallowing.

Phonetics

This muscle also plays a role in the formation of pharyngeal sounds, particularly in conjunction with the inferior pharyngeal constrictor muscle, and in the articulation of low, posterior vowels (such as "a").