The superior pharyngeal constrictor muscle is a

quadrilateral In Euclidean geometry, geometry a quadrilateral is a four-sided polygon, having four Edge (geometry), edges (sides) and four Vertex (geometry), corners (vertices). The word is derived from the Latin words ''quadri'', a variant of four, and ''l ...

muscle of the

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

. It is the uppermost and thinnest of the three pharyngeal constrictors. The muscle is divided into four parts according to its four distincts origins: a pterygopharyngeal, buccopharyngeal, mylopharyngeal, and a glossopharyngeal part. The muscle inserts onto the pharyngeal raphe, and pharyngeal spine. It is innervated by pharyngeal branch of the

vagus nerve The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibe ...

via the pharyngeal plexus. It acts to convey a bolus down towards the esophagus, facilitating swallowing.

Anatomy

The superior constrictor muscle is a quadrilateral, sheet-like muscle. It is thinner than the middle and inferior constrictor muscles.

Origin

The sites of origin of the muscles collectively are the pterygoid hamulus (and occasionally the adjoining posterior margin of the medial pterygoid plate) anteriorly, (the posterior margin of) the pterygomandibular raphe, the posterior extremity of the mylohyoid line of mandible, and (negligibly) the side of the tongue. Four parts of the muscle are distinguished according to the origin: * Pterygopharyngeal part - originating from the lower third of the posterior margin of the medial pterygoid plate and its hamulus * Buccopharyngeal part - originating from the pterygomandibular raphe * Mylopharyngeal part - originating from the alveolar process of the

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

above the posterior end of the mylohyoid line * Glossopharyngeal part - a few fibers originating from the side of the

tongue The tongue is a Muscle, muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for chewing and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper s ...

Insertion

The muscle's fibres extend posterior-ward from its origin to form the midline pharyngeal raphe which then attaches onto the pharyngeal tubercle (of the basilar part of the

occipital bone The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lob ...

Innervation

The superior pharyngeal constrictor muscle receives motor innervation from the pharyngeal plexus of vagus nerve.

Vasculature

Arterial supply is provided primarily by the pharyngeal branch of the ascending pharyngeal artery, and the tonsilar branch of the facial artery.

Relations

The interval between the upper border of the muscle and the base of the skull is closed by the pharyngeal aponeurosis, and is known as the sinus of Morgagni. There is an interval between superior pharyngeal constrictor and middle pharyngeal constrictor, this space contains glossopharyngeal nerve, lingual nerve and the stylopharyngeus muscle.McMinn, R., 1994. ''Last's anatomy: Regional and applied (9th ed).'' The superior fibers arch beneath the levator veli palatini muscle and the Eustachian tube.

Actions/movements

Constriction of the muscle constricts the superior portion of the

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, conveying it downward into the

esophagus The esophagus (American English), oesophagus (British English), or œsophagus (Œ, archaic spelling) (American and British English spelling differences#ae and oe, see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), c ...

Additional images

Image:Gray129.png,

Occipital bone The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lob ...

seen from outside Image:Gray177.png, Inner surface of the

Mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

seen from the side. The insertion of the mylopharyngeal part of the superior pharyngeal constrictor muscle is marked as "sup const". Image:Gray513.png, The internal carotid and vertebral arteries. Right side. Image:Gray1028.png, Muscles of the palate seen from behind. File:Slide3iiii.JPG,

Dissection Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause of ...

of the pharyngeal constrictors File:Slide2kaka.JPG, Deep dissection of the floor of mouth. Anterior view. File:Slide1kuku.JPG, Deep dissection of larynx, pharynx and tongue seen from behind

References

External links

* () * {{Authority control Muscles of the head and neck Pharynx