Muscles of mastication (practical 2)

Mandibular

All the muscles of mastication are innervated by branches of what nerve?

Lateral pterygoid muscles

Name the only muscle of mastication that does not elevate the mandible

Upper and lower

Name the two heads of the lateral pterygoids

Deep and superficial

Name the two heads of the medial pterygoids

1st

What pharyngeal arch are the muscles of mastication derived from Embryologically?

The upper head originates from the roof of the infratemporal fossa whilst the lower head originates from the lateral surface of the lateral plate of the pterygoid process. Inserts onto the capsule of the temporomandibular joint.

Where do the lateral pterygoid muscles originate and insert?

Deep head originates from the medial surface of the lateral pterygoid process and the pyramidal process of the palatine bone. The superficial head originates from the tuberosity of the maxilla and the pyramidal process of the palatine bone. Inserts onto the medial surface of the mandible, close to the angle.

Where do the medial pterygoid muscles originate and insert?

Originates from both the zygomatic arch and the maxillary process of the zygomatic bone. Inserts onto the lateral surface of the ramus of the mandible.

Where does the masseter muscle originate and insert?

Foramen ovale

How does the motor root of the mandibular nerve exit the skull?

Maxillary process of zygomatic bone; the masseter muscle

Identify this feature of the skull and note what attaches here

Pyramidal process of the palatine bone; the deep and superficial head of the medial pterygoids

Identify this feature of the skull and note what attaches here

Tuberosity of the maxilla; the superficial head to the medial pterygoids

Identify this feature of the skull and note what attaches here

Lateral pterygoid muscle; lateral pterygoid nerve

Identify this muscle and name the branch of the mandibular nerve that innervates it

Masseter muscle; masseteric nerve

Identify this muscle and name the branch of the mandibular nerve that innervates it

Medial pterygoid muscle; the main trunk of the mandibular nerve

Identify this muscle and name the branch of the mandibular nerve that innervates it

Temporalis muscle; deep temporal nerves

Identify this muscle and name the branch of the mandibular nerve that innervates it

Lateral pterygoid; protrudes the mandible and moves the mandible side to side

Identify this muscle and outline its function

Masseter; elevates the mandible

Identify this muscle and outline its function

Medial pterygoid; elevates the mandible and moves the mandible side to side

Identify this muscle and outline its function

Temporalis; elevates and retracts the mandible

Identify this muscle and outline its function

Temporalis, masseter and medial pterygoid

Name the muscles of mastication that have the ability to elevate the mandible?

Originates from the bone of the temporal fossa and the temporal fascia. Inserts onto the coronoid process of the mandible and the anterior margin of the mandible

Where does the temporalis muscle originate and insert?

Lateral and medial pterygoid muscles

Which muscles of mastication can move the mandible side to side?

Closes the mouth

With reference to the mouth, what is the effect of 'elevating' the mandible?