Throat Anatomy and Physiology

Question 1

What are the 2 parts of the oral cavity?

Answer 1

–Oral vestibule (between lips and teeth)

–Oral cavity proper

Question 2

What are the boundaries of the oral cavity?

Answer 2

–Lips to palatoglossal arch (anterior pillar)

–Palate to floor of mouth/tongue

–Buccal mucosa

Question 3

Where is the parotid gland placed?

Answer 3

The duct pierces the buccinator muscle, then opening up into the oral cavity on the inner surface of the cheek, usually opposite the maxillary second molar.

Question 4

Where is the submandibular gland placed?

Answer 4

Lying superior to the digastric muscle, each submandibular gland is divided into superficial and deep lobes, which are separated by the mylohyoid muscle.

Question 5

What does the lingual nerve supply?

Answer 5

Sensory innervation from the anterior two-thirds of the tongue

Question 6

Where does the lingual nerve come from?

Answer 6

The lingual nerve is a branch of the mandibular division of the trigeminal nerve. It also carries nerve fibers that are not part of the trigeminal nerve, including the chorda tympani nerve of the facial nerve, which provides special sensation (taste) to the anterior 2/3 part of the tongue

Question 7

What are the functions of the oral cavity?

Answer 7

Taste

Mastication

• Teeth, tongue

Speech

• Tongue, cheek, lips

Digestion

• Salivary enzymes

Swallowing

• Tongue, hard and soft palate

Question 8

What is the posterior 1 third of the tongue supplied by?

Answer 8

Supplied by CN 1X

Question 9

What are the most common papillae on the tongue?

Answer 9

Filliform papillae are the most numerous bu do not contain taste buds

Question 10

What is the effect of the intrinsic and extrinsic muscles of the tongue?

Answer 10

• Intrinsic muscles (alter shape)
• Extrinsic muscles (alter position)

Question 11

What are the extrinsic muscles of the tongue?

Answer 11

Genioglossus, styloglossus, hyoglossus and palatoglossus.

GP Harry Styles

Question 12

What is the nerve supply for the muscles of the tongue?

Answer 12

CN XII: hypoglossal nerve supply all except for palatoglossus – pharyngeal plexus (CN IX - X)

Question 13

What are the 4 muscles of mastication?

Answer 13

1. Lateral pterygoid
2. Medial pterygoid
3. Temporalis
4. Masseter

Question 14

What is the nerve supply for the muscles of mastication?

Answer 14

•CN V3

Question 15

What are the boundaries of the oropharynx?

Answer 15

• Lower border of soft palate to upper margin of epiglottis
• Palatoglossal arch to posterior pharyngeal wall
• Lateral: faucial pillars & palatine tonsils

Question 16

What is the epithelium of the oropharynx?

Answer 16

•Stratified, non-keratinised squamous

Question 17

What is the nerve supply of the oropharynx?

Answer 17

•Pharyngeal plexus- CN IX & X

Question 18

What is the blood supply of the hypopharynx?

Answer 18

Superior Thyroid Artery, the Lingual Artery and the Ascending Pharyngeal Artery.

Question 19

What is the nerve supply of the hypopharynx?

Answer 19

Nerve supply is from the pharyngeal plexus.

Question 20

What are the boundaries of the hypopharynx?

Answer 20

• Superior margin of epiglottis to lower border of cricoid cartilage
• Continuous with oesophagus
• Anterior wall: back of larynx

Question 21

What are the three subsites of the hypopharynx?

Answer 21

1. Pyriform sinus
2. Post-cricoid area
3. Posterior pharyngeal wall

Question 22

What are the three phases of swalowing?

Answer 22

Oral phase

Pharyngeal

Oesophageal

Question 23

What happens during the oral phase of swallowing?

Answer 23

• Tongue propels food (bolus) into pharynx
• Triggering swallowing reflex (afferent: CN V, IX, X – swallowing centre in medulla – efferent: CN VII, X, XII)

Question 24

What happens during the pharyngeal phase of swallowing?

Answer 24

• Soft palate pulled upwards
• Epiglottis covers the larynx, vocal cord approximate, larynx moves upward
• Upper oesophageal sphincter (UOS) relaxes
• Respiration is reflex inhibited

Question 25

What is the oesophageal phase of swallowing?

Answer 25

• Once bolus passed UOS, the sphinter constricts
• Bolus propelled downwards by peristaltic motion, reflex via myenteric plexus

Question 26

What is the function of the larynx?

Answer 26

–Part of respiratory tract

–Voice

–Swallowing

Question 27

What are the three parts of the larynx?

Answer 27

Supraglottis

Glottis

Subglottic

Question 28

What are the major cartilages of the larynx?

Answer 28

Question 29

What is the motor innervation of the larynx?

Answer 29

All intrinsic mucles supplied by recurrent laryngeal nerve except for cricothyroid muscle (external laryngeal nerve)

Question 30

What is the sensory innervation of the larynx?

Answer 30

Supraglottic: internal laryngeal nerve

Glottic and subglottic: recurrent laryngeal nerve

Question 31

Why does the left recurrent laryngeal nerve have a higher chance of injury during a chest operation?

Answer 31

The left recurrent laryngeal nerve has a longer course since it loops around the aortic arch instead of the right subclavian artery and therefore has a higher risk of injury during operative chest procedures

Question 32

What are the 5 portions of speech?

Answer 32

Respiration

Phonation

Resonation

Articulation

Prosody

Question 33

What is phonation?

Answer 33

Flow of air through different vocal chord positions, tension and length

Question 34

What is resonation?

Answer 34

• Oral/nasal speech balance
• Depend on nasopharynx, nasal cavity & oral cavity

Question 35

What is articulation?

Answer 35

•Production of speech , determined by action of lips, tongue and jaw

Question 36

Define prosody

Answer 36

• Production of syllable stress and emphasis
• Provide effective speech tone