Anatomy
Summary
Mastication, or chewing, involves the temporomandibular joint (TMJ). The TMJ is a synovial joint that serves as a sliding hinge, connecting the squamous portion of the temporal bone to the mandibular condyle. The mandibular nerve innervates the four primary muscles of mastication, which can be divided by whether they elevate or depress the mandible.
Muscles that elevate the mandible, or close the mouth, include the masseter, the temporalis, a wide fan-shaped muscle that also retracts the mandible, and the medial pterygoid which also protrudes the mandible. Finally, the lateral pterygoid, which has an inferior and superior head, depresses the mandible, opening the mouth, along with protrusion and side-to-side movement.
Lesson Outline
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FAQs
The primary muscles involved in mastication, or chewing, are the masseter, temporalis, medial pterygoid, and lateral pterygoid. They are all innervated by the mandibular nerve, which is a branch of cranial nerve five, and they work together to move the jaw.
The temporomandibular joint (TMJ) is a synovial joint that connects the mandible to the skull, allowing the jaw to move up and down, side to side, and back and forth.
The mandibular nerve, a branch of cranial nerve V, innervates the muscles of mastication, including: the masseter, temporalis, medial pterygoid, and lateral pterygoid.
The temporalis muscle is one of the four primary muscles involved in mastication. It is fan-shaped and innervated by the mandibular nerve. It elevates and retracts the mandible.
