Anatomy/Physiology of the throat

Question 1

What are the 2 parts of the oral cavity?

Answer 1

Oral vestibule (between lips and teeth)
Oral cavity (from lips to glossopalatine arch)

Question 2

Where does the parotid duct lie?

Answer 2

Runs from the parotid salivary gland up into the inner surface of the cheek

Question 3

Where does the submandibular duct lie?

Answer 3

Runs from the submandibular salivary gland to just superior to the digastric muscle

Question 4

Describe the innervation of the anterior 2/3 of the tongue.

Answer 4

Trigeminal nerve - Mandibular nerve - Lingual nerve

Lingual nerve then provides general somatic afferent innervation to the anterior 2/3 of the tongue or continues through the chorda tympani to provide special sensation to the anterior 2/3 tongue.

Question 5

Describe the innervation of the posterior 1/3 of the tongue.

Answer 5

CN IX - Glossopharyngeal nerve

Question 6

List the functions of the oral cavity.

Answer 6

Taste
Mastication
Speech
Digestion
Swallowing

Question 7

Describe the functions of tongue muscles.

Answer 7

Intrinsic muscles of the tongue alter shape
Extrinsic muscles of the tongue alter position

(CN XII - Hypoglossal nerve)

Question 8

Which muscles are involved in mastication?

Answer 8

Lateral pterygoid
Medial pterygoid
Temporal
Masseter

Question 9

Describe the boundaries of the oropharynx.

Answer 9

Lower border of the soft palate to upper margin of epiglottis.
Glossopalatine arch to posterior pharyngeal wall.

Question 10

Describe the histology of the oropharynx.

Answer 10

Stratified non-keratinised epithelium

Question 11

Describe the nerve supply of the oropharynx.

Answer 11

Pharyngeal plexus

CN IX & X

Question 12

Which blood vessels supply the hypopharynx?

Answer 12

Superior thyroid artery
Lingual artery
Ascending pharyngeal artery

Question 13

Describe the nerve supply of the hypopharynx.

Answer 13

Pharyngeal plexus

CN IX & X

Question 14

Describe the boundaries of the hypopharynx.

Answer 14

Superior border of the epiglottis to lower border of cricoid cartilage.
Back of larynx, continuous with oesophagus.

Question 15

What are the 3 phases of swallowing?

Answer 15

Oral
Pharyngeal
Oesophageal

Question 16

Describe the oral phase of swallowing.

Answer 16

Tongue propels bolus into pharynx, triggering swallowing reflex

Afferent - CN V, IX, X
Efferent - CN VII, X, XII

Question 17

Describe the pharyngeal phase of swallowing.

Answer 17

Soft palate pulled upwards
Epiglottis covers larynx
Larynx moves upwards
UOS relaxes
Respiration is reflex inhibited

Question 18

Describe the oesophageal phase of swallowing

Answer 18

UOS constricts once bolus passes

Bolus propelled downward by peristaltic motion via myenteric plexus

Question 19

List some functions of the larynx.

Answer 19

Swalllow
Voice
Part of respiratory tract

Question 20

Describe the innervation of the larynx.

Answer 20

Motor - CN X (recurrent laryngeal except external
laryngeal for cricothyroid muscles)
Sensory - Internal and left recurrent laryngeal