| Medial pterygoid | |
|---|---|
 The pterygoidei; thezygomatic arch and a portion of theramus of the mandible have been removed. (Internus is visible at center bottom.) | |
 Theotic ganglion and its branches. (Pterygoideus internus labeled at bottom right.) | |
| Details | |
| Origin | Deep head: medial side oflateral pterygoid plate behind the upper teeth Superficial head:pyramidal process of palatine bone andmaxillary tuberosity |
| Insertion | Medialangle of the mandible |
| Artery | Pterygoid branches of maxillary artery |
| Nerve | Mandibular nerve vianerve to medial pterygoid |
| Actions | Elevates mandible, closesjaw, helpslateral pterygoids in moving the jaw from side to side |
| Identifiers | |
| Latin | musculus pterygoideus medialis, musculus pterygoideus internus |
| TA98 | A04.1.04.009 |
| TA2 | 2113 |
| FMA | 49011 |
| Anatomical terms of muscle | |
Themedial pterygoid muscle (orinternal pterygoid muscle) is a thick, quadrilateral muscle of theface. It is supplied by themandibular branch of thetrigeminal nerve (V). It is important inmastication (chewing).
The medial pterygoid muscle consists of two heads. The bulk of the muscle arises as a deep head from just above the medial surface of thelateral pterygoid plate. The smaller, superficial head originates from themaxillary tuberosity and the pyramidal process of thepalatine bone.
Its fibers pass downward, lateral, and posterior, and are inserted, by a strong tendinous lamina, into the lower and back part of the medial surface of theramus and angle of themandible, as high as themandibular foramen. The insertion joins themasseter muscle to form a common tendinous sling which allows the medial pterygoid and masseter to be powerful elevators of the jaw.
The medial pterygoid muscle is supplied by themedial pterygoid nerve, a branch of themandibular nerve, itself a branch of thetrigeminal nerve (V). This also supplies thetensor tympani muscle and thetensor veli palatini muscle. The medial pterygoid nerve is a main trunk from the mandibular nerve, before the division of the trigeminal nerve - this is unlike thelateral pterygoid muscle, and all other muscles ofmastication which are supplied by the anterior division of the mandibular nerve.
The medial pterygoid muscle has functions including elevating the mandible (closing the mouth), protruding the mandible,mastication (especially for when themaxillary teeth and themandibular teeth are close together),[1] and excursing the mandible (contralateral excursion occurs with unilateral contraction).
This article incorporates text in thepublic domain frompage 387 of the 20th edition ofGray's Anatomy(1918)
