The Pharynx

Question 1

What is the pharynx?

Answer 1

A muscular tube

Connects the larynx and oesophagus to the nasal cavities

Question 2

What can pass down the pharynx?

Answer 2

Air and food

Question 3

Where, precisely, does the pharynx begin and end?

Answer 3

Begins at the base of the skull

Ends inferior to the cricoid cartilage (C6)

Question 4

Name the three parts of the pharynx

Answer 4

Nasopharynx

Oropharynx

Laryngopharynx

Question 5

What are the muscles of the pharynx innervated by?

Answer 5

The vagus nerve (CN X)

Except for the stylopharyngeus, innervated by the glossopharyngeal nerve (CN IX)

Question 6

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

Answer 6

Contract sequentially from superior to inferior to constrict the lumen and propel bolus of food inferiorly into the oesophagus.

Question 7

Structure of the circular muscles of the pharynx?

Answer 7

Stacked like glasses

Form an incomplete muscular circle

Question 8

Name the circular muscles of the pharynx and the parts in which they are found.

Answer 8

Superior pharyngeal constrictor - oropharynx

Middle pharyngeal constrictor - laryngopharynx

Inferior pharyngeal constrictor - laryngopharynx

Question 9

What are the two components of the inferior pharyngeal constrictor

Answer 9

Superior (thyropharyngeus) - has oblique fibres that attach to the thyroid cartilage

Inferior (cricopharyngeus) - horizontal fibres attaching to the cricoid cartilage

Question 10

Generally, what is the structure of the wall of the pharynx?

Answer 10

Pharyngeal mucosa

Incomplete ring of lymphoid tissue

Longitudinal muscular layer

Circular muscular layer

Buccopharyngeal fascia

Question 11

Function of the longitudinal muscles of the pharynx?

Answer 11

Shorten and widen the pharynx

Elevate it during swallowing

Question 12

Attachements of the longitudinal muscles of the pharynx?

Answer 12

Stylopharyngeus - styloid process of temporal bone to the pharynx

Palatopharyngeus - hard palate of oral cavity to the pharynx

Salpingopharyngeus - Eustachian tube to pharynx

Question 13

What extra function does the salpingopharyngeus perform?

Answer 13

Opens the Eustachian tube to equalise pressure in the middle ear with the atmosphere.

Question 14

Sensory innervation of the pharynx?

Answer 14

Nasopharynx - maxillary

Oropharynx - glossopharyngeal

Laryngopharynx - vagus

Question 15

Sympathetic innervation to the pharynx?

Answer 15

From the superior cervical ganglion

Question 16

Arterial supply to the pharynx?

Answer 16

Branches of the external carotid

• ascending pharyngeal
• lingual
• facial
• maxillary

Question 17

Venous drainage of the pharynx?

Answer 17

Pharyngeal venous plexus, drains into the internal jugular

Question 18

Where does the nasopharynx run between?

Answer 18

Base of the skull to the soft palate

Question 19

Function of the nasopharynx?

Answer 19

Extension of the nasal cavity

Conditions inspired air and propogates it into the larynx

Question 20

Epithelium of the nasopharynx?

Answer 20

Ciliated pseudostratified columnar with goblet cells

Question 21

Where are the adenoid tonsils found?

Answer 21

In the posterio-supeior nasppharynx

Question 22

What can cause enlargement of the adenoid tonsils?

Answer 22

Viral infections of the upper respiratory tract

Question 23

What can happen if the adenoids keep becoming infected and enlarged?

Answer 23

Obstruct the opening of the Eustachian tube

Prevents equalising of pressure in the middle ear and normal drainage of fluids for excretion

Glue ear

Question 24

Where does the oropharynx run from and to?

Answer 24

Soft palate and supeior border of the epiglottis

Question 25

What does the oropharynx contain?

Answer 25

Posterior third of the tongue Lingual tonsils Palatine tonsils Superior constrictor muscle

Question 26

What is the function of the oropharynx?

Answer 26

Voluntary and involuntary phases of swallowing

Question 27

Where are the palatine tonsils found?

Answer 27

In the tonsilar fossa between the palatoglossal and palatopharyngeal arches of the oral cavity

Question 28

Where are the lingual tonsils found?

Answer 28

Inferiorly to the tongue

Question 29

What is inflammation of the palatine tonsils (tonsilitis) accompanied by?

Answer 29

Enlarged jugulo-digastric lymph nodes

Question 30

What can bleed during a tonsillectomy?

Answer 30

External palatine vein Tonsilar branch of the facial artery

Question 31

What can be damaged during a tonsillectomy?

Answer 31

Glossopharyngeal nerve Internal carotid artery

Question 32

If an infection spreads from the palatine tonsils to the peritonsilar tissue, what is this known as and what happens? Why is it an emergency?

Answer 32

Cause an abscess Can get deviation of the uvula (quinsy) Potential obstruction to the pharynx

Question 33

How is quinsy treated?

Answer 33

Drain the abscess Antibiotics

Question 34

Where does the laryngopharynx run between?

Answer 34

Superior border of the epiglottis Inferior border of the cricroid cartilage (C6) Becomes continuous with the oesophagus

Question 35

Where is the laryngopharynx found in relation to the larynx?

Answer 35

Posterior to the larynx

Question 36

What does the laryngopharynx contain?

Answer 36

Middle and inferior pharyngeal constrictors

Question 37

Where can foreign objects become lodged in the pharynx?

Answer 37

Valleculae in the nasopharynx Piriform fossae in the laryngopharynx

Question 38

How are objects in the piriform fossae visualised and removed?

Answer 38

With a pharyngoscope

Question 39

What can be affected when something is lodged in the piriform fossa?

Answer 39

Can compress the internal laryngeal nerve and the recurrent laryngeal nerve

Question 40

What happens during swallowing normally with the inferior pharyngeal constrictor?

Answer 40

The superior part - thyropharyngeus - contracts The cricopharyngeus relaxes This allows the bolus to be propelled into the oesophagus and prevent intrapharyngeal pressure from rising

Question 41

What can happen if there is not the relaxation of the cricopharyngeus during swallowing?

Answer 41

Intrapharyngeal pressure rises Pharyngeal mucosa forms a midline diverticulum between the thyropharyngeus and cricopharyngeus Food can accumulate here, leading to dysphagia

Question 42

Where are the widest and narrowest parts of the pharynx?

Answer 42

Widest (5cm) opposite the hyoid Narrowest (1.5cm) at the inferior end

Question 43

What is between the muscle layer and the mucosa of the pharynx?

Answer 43

The pharyngobasilar fascia

Question 44

What are the phases of swallowing?

Answer 44

Voluntary phase Pharyngeal phase Oesophageal phase

Question 45

What happens in the voluntary phase of swallowing?

Answer 45

Tongue moves bolus to the back of the pharynx

Question 46

What happens in the pharyngeal phase of swallowing?

Answer 46

Afferent info from pressure receptors in the palate and anterior pharynx reaches the swallowing centre in the brain stem Triggers movements: * Inhibition of breathing * Raising of larynx * Closure of the glottis * Opening of the upper oesophageal sphincter

Question 47

What happens in the oesophaeal phase of swallowing?

Answer 47

* Wave of peristalsis sweeps down the oesophagus, propelling the bolus into the stomach in about 9 seconds * Coordinated by extrinsic nerves from the swallowing centre of the brain * Lower oesophageal sphincter opens

Question 48

What triggers the gag reflex and what is the pathway?

Answer 48

Touching the back of the oropharynx Afferent pathway - glossopharyngeal Efferent pathway - vagus nerve

Question 49

Clinical features of enlarged adenoids?

Answer 49

* Nasal obstruction * Mouth breathing and nasal speech * Feeding difficulty especially in infants * Snoring/obstructive sleep apnoea * Block opening of Eustachian tube