The middle pharyngeal constrictor is a fan-shaped
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of mus ...
located in the
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
. It is one of three
pharyngeal constrictor
The pharyngeal muscles are a group of muscles that form the pharynx, which is posterior to the oral cavity, determining the shape of its lumen, and affecting its sound properties as the primary resonating cavity.
The pharyngeal muscles (involunta ...
s. Similarly to the
superior
Superior may refer to:
*Superior (hierarchy), something which is higher in a hierarchical structure of any kind
Places
*Superior (proposed U.S. state), an unsuccessful proposal for the Upper Peninsula of Michigan to form a separate state
*Lake ...
and
inferior pharyngeal constrictor muscles, the middle pharyngeal constrictor is innervated by a branch of the
vagus nerve
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...
through the
pharyngeal plexus. The middle pharyngeal constrictor is smaller than the
inferior pharyngeal constrictor muscle.
Structure
The middle pharyngeal constrictor arises from the whole length of the upper border of the
greater cornu
The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical vertebra ...
of the
hyoid bone
The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical verteb ...
, from the
lesser cornu, and from the
stylohyoid ligament
The stylohyoid ligament is a ligament that connects the hyoid bone to the temporal styloid process (of the temporal bone of the skull).
Structure
The stylohyoid ligament connects the lesser horn of hyoid bone to the styloid process of the t ...
.
The fibers diverge from their origin: the lower ones descend beneath the
constrictor inferior
The inferior pharyngeal constrictor muscle is a skeletal muscle of the neck. It is the thickest of the three outer pharyngeal muscles. It arises from the sides of the cricoid cartilage and the thyroid cartilage. It is supplied by the vagus nerve ( ...
, the middle fibers pass transversely, and the upper fibers ascend and overlap the
constrictor superior
The superior pharyngeal constrictor muscle is a muscle in the pharynx. It is the highest located muscle of the three pharyngeal constrictors. The muscle is a quadrilateral muscle, thinner and paler than the inferior pharyngeal constrictor muscle ...
.
It is inserted into the posterior median fibrous
raphe, blending in the middle line with the muscle of the opposite side.
Function
As soon as the
bolus of food is received in the pharynx, the elevator muscles relax, the pharynx descends, and the constrictors contract upon the bolus, and convey it downward into the
esophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...
.
They also have respiratory mechanical effects.
Additional images
Image:Gray186.png, Hyoid bone. Anterior surface. Enlarged.
Image:Gray385.png, Muscles of the neck. Lateral view.
Image:Slide12mmm.JPG, Middle pharyngeal constrictor muscle
Image:Slide4iiii.JPG, Middle pharyngeal constrictor muscle
Image:Slide1kuku.JPG, Deep dissection of larynx, pharynx and tongue seen from behind
Image:Slide2kuku.JPG, Deep dissection of larynx, pharynx and tongue seen from behind
Image:Slide3kuku.JPG, Deep dissection of larynx, pharynx and tongue seen from behind
References
Further reading
*Its role in speech:
*Its role in Hyoid bone syndrome:
External links
* ()
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Muscles of the head and neck
Pharynx