Chewing, tasting and swallowing. Flashcards
What are the main muscles of mastication?
Temporalis
Masseter
Lateral pterygoid
Medial pterygoid
Name the muscles involved in closing the mouth.
Temporalis
Masseter
Medial pterygoid (minor role)
What is the main role of the medial pterygoid?
Swinging the mandible from side to side
What is the function of the lateral pterygoid?
Opening the mouth (assisted by the digastric muscle)
At which joint do the mandible and cranium articulate?
The temporomandibular joint.
At rest where does the head of the mandible lie?
The glenoid fossa.
With which muscle is the disc of fibrocartilage found in the glenoid fossa continuous?
The lateral pterygoid.
Describe the movement of the mandibular head in the glenoid fossa. Why is this important?
The mandibular head rotates anteriorly and slides out of the fossa as the mouth opens. This freedom within the joint allows the mandibular head to move from side to side.
How many heads does the lateral pterygoid muscle have and where do they insert?
Two, upper and lower. They insert into the neck of the mandible and part of the TMJ.
What is the origin of the upper head of lateral pterygoid?
Sphenoid bone.
What is the origin of the lower head of lateral pterygoid?
Lateral pterygoid plate.
How does the lateral pterygoid open the mouth?
It pulls the neck of the mandible and parts of the TMJ forward, which protrudes the mandible but does not rotate it.
Which muscle is responsible for the rotation of the mandibular head?
The digastric.
What is the origin of the digastric muscle?
The mastoid process.
What is unusual about the digastric muscle?
Is has two bellies - connected by a tendon.