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 The pterygoid hamulus is a hook-like process at the lower extremity of the medial pterygoid plate of the sphenoid bone of the skull. It is the superior origin of the pterygomandibular raphe, and the tensor veli palatini muscle courses around it ...

(and occasionally the adjoining posterior margin of the

medial pterygoid plate The pterygoid processes of the sphenoid (from Greek ''pteryx'', ''pterygos'', "wing"), one on either side, descend perpendicularly from the regions where the body and the greater wings of the sphenoid bone unite. Each process consists of a med ...

) 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

and its hamulus * Buccopharyngeal part - originating from the pterygomandibular raphe * Mylopharyngeal part - originating from the

alveolar process The alveolar process () is the portion of bone containing the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The alveolar process is covered by gums within the mouth, terminating roughly along the line of the mandibu ...

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 The mylohyoid line is a bony ridge on the internal surface of the mandible. It runs posterosuperiorly. It is the site of origin of the mylohyoid muscle, the superior pharyngeal constrictor muscle, and the pterygomandibular raphe. Structure The ...

* 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 The pharyngeal plexus is a nerve plexus located upon the outer surface of the pharynx. It contains a motor component (derived from the vagus nerve (cranial nerve X)), a sensory component (derived from the glossopharyngeal nerve (cranial nerve ...

Vasculature

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

facial artery The facial artery, formerly called the external maxillary artery, is a branch of the external carotid artery that supplies blood to superficial structures of the medial regions of the face. Structure The facial artery arises in the carotid t ...

Relations

The interval between the upper border of the muscle and the

base of the skull The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria. Structure Structures found at the base of the skull are for ...

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 The levator veli palatini () is a muscle of the soft palate and pharynx. It is innervated by the vagus nerve (cranial nerve X) via its pharyngeal plexus. During swallowing, it contracts, elevating the soft palate to help prevent food from enteri ...

muscle and the

Eustachian tube The Eustachian tube (), also called the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, of which it is also a part. In adult humans, the Eustachian tube is approximately long and in diameter. It ...

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