The tensor veli palatini muscle (tensor palati or tensor muscle of the velum palatinum) is a thin, triangular muscle of the head that tenses the

soft palate The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft biological tissue, tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is ...

and opens 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 ...

to equalise pressure in the middle ear.

Structure

The tensor veli palatini muscle is thin and triangular in shape.

Origin

It arises from the

scaphoid fossa In the pterygoid processes of the sphenoid, above the pterygoid fossa is a small, oval, shallow depression, the scaphoid fossa, which gives origin to the tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of t ...

of the pterygoid process of the sphenoid anteriorly, the (medial aspect of the)

spine of sphenoid bone The sphenoidal spine (Latin: "''spina angularis''") is a downwardly directed process at the apex of the great wings of the sphenoid bone that serves as the origin of the sphenomandibular ligament. Additional images File:Spine of sphenoid bone. ...

posteriorly, and - between the aforementioned anterior and posterior attachments - from the anterolateral aspect of the membranous wall of the pharyngotympanic tube. At the muscle's origin, some of its muscle fibres may be continuous with those of the

tensor tympani muscle The tensor tympani is a muscle within the middle ear, located in the bony canal above the bony part of the auditory tube, and connects to the malleus bone. Its role is to dampen loud sounds, such as those produced from chewing, shouting, or thund ...

Insertion

Inferiorly, the muscle converges to form a tendon of attachment. This tendon winds medially around 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 ...

(with a small bursa interposed between the two) to insert into the palatine aponeurosis and into the bony surface posterior to the palatine crest of the horizontal plate of palatine bone.

Dilator tubae component

Some of the muscle's fibres insert onto the lateral lamina of the cartilaginous part of pharyngotympanic tube and adjacent connective tissue, and the Ostmann's fat pad. The portion of the muscle with these attachments is sometimes called the ''dilator tubae''.

Innervation

The tensor veli palatini muscle receives motor innervation from the

mandibular nerve In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth Cranial nerves, cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which ...

(CN V₃) (a branch of the

trigeminal nerve In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions ...

(CN V)) via the

nerve to medial pterygoid The medial pterygoid nerve (nerve to medial pterygoid, or internal pterygoid nerve) is a nerve of the head. It is a branch of the mandibular nerve (CN V3). It supplies the medial pterygoid muscle, the tensor veli palatini muscle, and the tensor ...

. It is the only muscle of the palate not innervated by the pharyngeal plexus, which is formed by the vagal and glossopharyngeal nerves.

Relations

It is situated anterolaterally to 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. From its origin to its insertion, the muscle passes vertically between 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 ...

and the

medial pterygoid muscle The medial pterygoid muscle (or internal pterygoid muscle) is a thick, quadrilateral muscle of the face. It is supplied by the mandibular branch of the trigeminal nerve (V). It is important in mastication (chewing). Structure The medial pter ...

Actions/movements

Bilateral contraction of the two tensor veli palatini muscles makes the

(especially its anterior portion) taut, as well as flattening the arch of the soft palate and thereby depressing it. Unilateral contraction draws the soft palate ipsilaterally.

Function

The tensor veli palatini tenses the soft palate and by doing so, assists the

in elevating the palate to occlude and prevent entry of food into the nasopharynx during swallowing. The tensed palate consequently provides a stable platform for elevation of the pharynx during swallowing by the pharyngeal muscles. Since it is also attached to the lateral cartilaginous lamina of the pharyngotympanic tube (auditory tube or Eustachian tube), it assists in its opening during swallowing or yawning to allow air pressure to equalize between the

tympanic cavity The tympanic cavity is a small cavity surrounding the bones of the middle ear. Within it sit the ossicles, three small bones that transmit vibrations used in the detection of sound. Structure On its lateral surface, it abuts the external audit ...

and the outside air. Equalization of air pressure in the tympanic cavity is essential for preventing damage to the

tympanic membrane In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit changes in pressur ...

and a resulting loss of hearing acuity.

Additional images

Image:Gray782 updated.png, Mandibular division of trigeminal nerve, seen from the middle line

References

External links

{{Authority control Muscles of the head and neck Pharynx