0505 - Pharynx - EG

Question 1

Describe the articular surface of the temporo-mendibular joint.

Answer 1

The articular surface of the TMJ extends from the mandibular surface anteriorly onto the anterior tubercle. The head of the mandible rotates and glides during movements of the jaw across this surface.

Question 2

What ligament normally prevents dislocation of the TMJ?

Answer 2

the spheno-mandibular ligament.

Question 3

What occurs in a TMJ dislocation?

Answer 3

The TMJ is vulnerable as it glides forward to sit under the articular tubercle when mouth is open wide as it can become dislocated anteriorly in front of the tubercle where it can be manoeuvred back into position by pulling down and pushing back.

Question 4

What are the four muscles of mastication and which nerve innervates them?

Answer 4

lateral pterygoid muscle, medial pterygoid muscle, temporalis muscle, and masseter muscle, all innervated by V3 (maxillary branch of the trigeminal nerve)

Question 5

Which muscles are the deep muscles for mastication?

Answer 5

lateral pterygoid and medial pterygoid

Question 6

Which muscles are the superficial muscles for mastication?

Answer 6

temporalis and masseter

Question 7

Which muscle of mastication protrudes the mandible?

Answer 7

lateral pterygoid.

Question 8

Which muscle of mastication only elevates the mandible (but not the most powerful elevator)?

Answer 8

medial pterygoid.

Question 9

Which muscle of mastication both elevates and retracts the mandible?

Answer 9

temporalis

Question 10

Which muscle of mastication provides powerful elevation of the jaw?

Answer 10

masseter

Question 11

What is the action of the lateral pterygoid muscle?

Answer 11

to pull the mandible forward (protraction of the jaw)

Question 12

What is the action of the medial pterygoid muscle?

Answer 12

elevation of the mandible (but not that powerful an action)

Question 13

What is the action of the temporalis muscle?

Answer 13

elevation and retraction of the mandible.

Question 14

What is the action of the masseter muscle?

Answer 14

Very powerful elevation of the jaw.

Question 15

Which muscles of mastication are involved in elevation?

Answer 15

temporalis, masseter, medial pterygoid.

Question 16

Which muscle elevates the soft palate and what nerve innervates it?

Answer 16

levator veli palatini (LVP), innervated by XI (via X)

Question 17

Which muscle tenses the palate and what nerve innervates it?

Answer 17

tensor veli palatini (TVP), innervated by V3

Question 18

What muscle is used by singers to modulate the position of the soft palate?

Answer 18

tensor veli palatine (TVP)

Question 19

List the four palatine muscles and their innervation.

Answer 19

palatopharyngeus (XI via X)palatoglossus (XI via X)levator veli palatini (XI via X)tensor veli palatini (V3)

Question 20

Briefly describe the larynx.

Answer 20

a muscular tube attached to the base of the skull and located posterior to the nasal cavity (nasopharynx), oral cavity (oropharynx), and larynx (laryngopharynx) that continues into the oesophagus. Posteriorly lies the spine.

Question 21

List the muscles of the larynx and their innervation.

Answer 21

Three pharyngeal constrictors (XI): inferior, middle and inferior constrictors; three longitudinal muscles: palatopharyngeus (XI), salpingopharyngeus (XI), stylopharyngeus (XI)

Question 22

What nerves supply the sensory innervation of the pharynx

Answer 22

nasopharynx by V2, oropharynx by IX, laryngopharynx by X.

Question 23

Describe the process of swallowing (the first step within the mouth)

Answer 23

voluntary initiation of swallowing in the mouth as tongue pushes bolus back and back of tongue elevates, soft palate contracts, to activate reflex, palatopharyngeal sphincter closes to prevent bolus from entering nasopharynx.

Question 24

Describe the process of swallowing (second step within the pharynx)

Answer 24

in the pharynx the hyoid bone and larynx are elevated by suprahyoids, epiglottis depresses to close over the larynx, bolus divides and deviates laterally into the piriform recess, laryngopharynx elevates and cricopharyngeus relaxes.

Question 25

What muscle is also known as the superior oesophageal sphincter?

Answer 25

cricopharyngeus.