Session 9 - Oral Cavity, Tongue And Pharynx

Question 1

What are the borders of the oral cavity?

Answer 1

Lateral walls - buccinators
Roof - hard and soft palates
Floor - tongue and muscular diaphragm

Question 2

What is the posterior limit of the oral cavity?

Answer 2

The oropharyngeal isthmus

Question 3

What is the oropharyngeal isthmus?

Answer 3

An arch between the oral cavity and oropharynx, formed by the soft palate above and the upper surface of the tongue below.

Question 4

What are the sides of the oropharyngeal isthmus formed by?

Answer 4

The anterior and posterior pillars of the fauces (palatoglossal fold and palatopharyngeal fold)

Question 5

The folds of the fauces are formed by what two muscles?

Answer 5

Palatoglossus muscle (anterior)
Palatopharyngeal muscle (posterior)

Question 6

Where does the palatoglossus muscle run from and to?

Answer 6

From the soft palate to the tongue

Question 7

Where does the palatopharyngeal muscle run from and to?

Answer 7

From the soft palate to the pharynx

Question 8

When do the palatoglossus and palatopharyngeal muscles contract and what are their actions?

Answer 8

Contract during chewing. They act to pull the soft palate down, closing the oropharyngeal isthmus, therefore ensuring that food remains in the oral cavity while chewing.

Question 9

What fossa is found between the palatoglossal and palatopharyngeal folds and what does it contain?

Answer 9

Tonsillar fossa, in which the palatine tonsil is found.

Question 10

Which tonsils make up Waldeyer’s ring?

Answer 10

1 pharyngeal tonsil
2 tubal tonsils
2 palatine tonsils
1 lingual tonsil

Question 11

Which tonsil is easily visible due to inflammation in tonsillitis?

Answer 11

Palatine tonsil

Question 12

Name the salivary glands.

Answer 12

Sublingual
Submandibular
Parotid

Question 13

Is salivary gland secretion stimulated by sympathetic or parasympathetic stimulation?

Answer 13

Parasympathetic

Question 14

Salivary gland stones can form in the ducts draining the salivary glands into the oral cavity. Which salivary gland is most commonly affected by stones?

Answer 14

Submandibular gland

Question 15

Are the intrinsic muscle of the tongue attached to bone?

Answer 15

No, they blend with the extrinsic muscles of the tongue.

Question 16

What is the action of the intrinsic muscles of the tongue?

Answer 16

Act to alter the shape of the tongue

Question 17

What are the actions of the extrinsic muscles of the tongue?

Answer 17

Act to change the position of the tongue - allow protrusion, retraction and side-to-side movement.
Anchor the tongue to the surrounding structures (hyoid bone and mandible below, styloid process and soft palate above).

Question 18

Which extrinsic muscle of the tongue is most important to note and what is its action?

Answer 18

Genioglossus.

Protrudes the tongue.

Question 19

How can the function of the hypoglossal nerve (CN XII) be tested?

Answer 19

Ask patient to stick out their tongue. (Action of genioglossus muscle)

Question 20

All muscles of the tongue (except one) are innervated by what nerve?

Answer 20

Hypoglossal nerve (CN XII)

Question 21

Which muscle of the tongue is not innervate by the hypoglossal nerve?

Answer 21

Palatoglossus (muscle forming the shape of the anterior arch)

Question 22

Which nerve innervates the palatoglossus?

Answer 22

Vagus nerve (CN X)

Question 23

Tongue has embryological origins from which pharyngeal arches?

Answer 23

Pharyngeal arches 1, 3 and 4.

Question 24

General sensation to the anterior 2/3 of the tongue is carried by what nerve?

Answer 24

Trigeminal nerve, specifically the lingual nerve (a branch of CN Vc).

Question 25

What nerve supplies special sensory fibres for taste to the anterior 2/3 of the tongue?

Answer 25

Chorda tympani (branch of facial nerve).

Question 26

What nerve supplies both general sensation and taste sensation fibres to the posterior 1/3 of the tongue?

Answer 26

Glossopharyngeal nerve (CN IX)

Question 27

The glossopharyngeal nerve also carries parasympathetic fibres to which salivary gland?

Answer 27

Parotid gland

Question 28

Asking a patient to open their mouth and say ‘ahhh’ is a test of which cranial nerve?

Answer 28

Vagus nerve (CN X)

Question 29

When asked to open their mouth and say ‘ahhh’ a patients uvula may deviate to one side. What does this indicate?

Answer 29

Deviation of the uvula to one side indicates weakness of the soft palate on the contralateral side (opposite side) to the deviation. This therefore indicates an vagus nerve (CN X) lesion.

Question 30

The gag reflex tests the integrity of which nerves?

Answer 30

``` Glossopharyngeal nerve (CN IX) (afferent limb of the gag reflex) Vagus nerve (CN X) (efferent limb of the gag reflex) ```

Question 31

Lesions affecting the hypoglossal nerve on one side of the tongue will cause the tongue to deviate in which direction when protruded?

Answer 31

Deviates towards the side of the lesion.

Question 32

The pharynx extends down to which vertebral level?

Answer 32

C6

Question 33

The posterior wall of the pharynx is covered by what type of fascia?

Answer 33

Buccopharyngeal fascia

Question 34

What are the three parts of the pharynx?

Answer 34

Nasopharynx Oropharynx Laryngopharynx

Question 35

The nasopharynx lies superiorly to what?

Answer 35

Soft palate

Question 36

What structures are found in the nasopharynx?

Answer 36

``` The orifice of the Eustachian (Pharyngotympanic) tube. Pharyngeal tonsil (adenoids) ```

Question 37

What are the upper and lower limits of the oropharynx?

Answer 37

The oropharynx extends from the soft palate to the superior border of the epiglottis.

Question 38

Which vertebral body lies posteriorly to the nasopharynx?

Answer 38

C1

Question 39

Which vertebral bodies lie posteriorly to the oropharynx?

Answer 39

C2 and C3

Question 40

What are the upper and lower limits of the laryngopharynx?

Answer 40

Extends from the epiglottis to the oesophagus at the level of the lower border of the cricoid cartilage, and also extends behind the laryngeal inlet.

Question 41

Which vertebral bodies lie posteriorly to the laryngopharynx?

Answer 41

C3-C6

Question 42

What are the small depression found on either side of the laryngeal inlet called?

Answer 42

Piriform fossa

Question 43

What muscles are the wall of the pharynx formed by?

Answer 43

Superior, middle and inferior constrictors.

Question 44

What nerve are the circular constrictor muscles of the pharynx innervated by?

Answer 44

Vagus nerve (CN X)

Question 45

What is the function of the constrictor muscles of the pharynx?

Answer 45

Sequential relaxation and contraction to propel food along the pharynx into the oesophagus.

Question 46

What is Killian’s dehiscence?

Answer 46

A small area of weakness found between the two muscle bellies of the inferior constrictor.

Question 47

What is a pharyngeal pouch (Zenker’s diverticulum) and how do they form?

Answer 47

A pharyngeal pouch is a herniation through Killian’s dehiscence. If there is uncoordinated swallowing, pressure in the pharynx can increase due the the constrictor muscle contracting against a closed oesophageal sphincter. This can cause part of the pharyngeal mucosa to herniate through Killian’s dehiscence forming a pharyngeal pouch.

Question 48

What symptoms are caused by a pharyngeal pouch?

Answer 48

May be asymptomatic Dysphagia Regurgitation of food Halitosis (bad breath)

Question 49

The vagus nerve supplies all muscles of the pharynx and soft palate except for which?

Answer 49

Stylopharyngeus (supplied by CN IX)

Question 50

General sensory to the nasopharynx is supplied by what nerve?

Answer 50

Maxillary nerve (CN Vb)

Question 51

General sensory to the oropharynx is supplied by what nerve?

Answer 51

Glossopharyngeal nerve (CN IX) (The pharyngotympanic tube is also supplied by CN IX even though it is found in the nasopharynx).

Question 52

The laryngopharynx receives general sensory innervation from what nerve?

Answer 52

Vagus nerve (CN X)