Infratemporal Fossa

Question 1

What are the four muscles of mastication?

Answer 1

The masseter, temporalis, lateral ptyergoid and medial pterygoid muscles.

Question 2

What is the action of muscle of mastication?

Answer 2

Masseter: elevation of mandible;

Temporalis: elevation/retraction of mandible

Lateral ptyergoid: depression, protraction and side-to-side movements of the mandible (opens mouth)

Medial pterygoid: elevation, protraction and side-to-side movements of the mandible. (closes mouth)

Question 3

Name the sole depressor of the mandible.

Answer 3

The lateral ptyergoid muscle. Accessory muscles include the suprahyoid muscles

Question 4

What specific nerve supplies motor innervation to these muscles?

Answer 4

The mandibular division of the trigeminal nerve (V3)

Question 5

Which of these 4 muscles attach to the lateral pterygoid process?

Answer 5

The lateral pterygoid attaches to the lateral aspect of the lateral pterygoid process (plate);

The medial pterygoid attaches to the medial aspect of the lateral ptytergoid process

(be sure you can locate these on the skull).

Question 6

Which of these 4 muscles inserts into the TMJ?

Answer 6

The lateral pterygoid muscle attaches to the ANTERIOR portion of the articular disc

Question 7

Which of these 4 muscles attaches to the coronoid process?

Answer 7

The temporalis.

Question 8

Which of these 4 muscles attaches to the angle of the mandible?

Answer 8

The masseter laterally and the medial pterygoid medially. (they are like mirror images of one another)

Question 9

From what vessel does the maxillary artery arise?

Answer 9

It is one of the two terminal branches of the external carotid artery.

Question 10

What are the three clinically important branches and what does each supply?

Answer 10

The inferior alevolar (supplies the lower teeth);

The middle meningeal (supplies the dura);

The posterior superior alveolar (supplies the upper teeth and maxillary sinus).

Question 11

What is the continuation of the maxillary artery called after it passes through the pterygomaxillary fissure?

Answer 11

The sphenopalatine artery

Question 12

What does this continuation supply?

Answer 12

The nasal cavity

Question 13

What are the main branches off the mandibular division of the trigeminal nerve?

Answer 13

From the stump of V3: the auriculotemporal;

From the anterior division: motor branches to the mm. of mastication and the buccal n.;

From the posterior division: the lingual and the inferior alevolar. (under the inferior head of lateral ptyergoid)

Question 14

What is the general function of each of these mandibular n. branches?

Answer 14

Auriculotemporal: sensory to the skin in front of the ear;

Buccal n.: sensory to the mucosa of the inside of the cheek;

Lingual: general sensation to the anterior 2/3 of the tongue;

Inferior alevolar: sensory to the lower teeth.

Question 15

Which of these major sensory branches gives off a small motor root to the region under the mandible?

Answer 15

The inferior alveolar. Gives nerve to mylohyoid

Question 16

What is this nerve and what does it supply in this region?

Answer 16

The nerve to the mylohyoid; it is motor to the mylohyoid and the anterior belly of the digastric.

Question 17

How does the special sense of taste reach the tongue?

Answer 17

The fibers for the special sensation of taste leave the facial nerve as it travels within the temporal bone in a branch called the chorda tympani. The chorda tympani passes through the middle ear cavity and enters the back side of the lingual nerve within the infratemporal fossa. Taste fibers for the anterior 2/3 of the tongue are distributed with the lingual nerve.