Sensory & Motor Innervation of the Upper Airway

Question 1

the vagus nerve divides into (2)

Answer 1

1. Superior Laryngeal Nerve

2. Recurrent Laryngeal Nerve

Question 2

Superior Laryngeal Nerve divisions

Answer 2

1. External (M)
2. Internal (S)

SEM
SIS

Question 3

sensory innervation of anterior nasal septum and lateral walls

Answer 3

Anterior ethmoidal nerve

CN V (Trigeminal nerve) → Ophthalmic division → anterior ethmoidal nerve

Question 4

sensory innervation of posterior nasal septum

Answer 4

nasopalatine nerves & sphenopalatine ganglion

CN V (Trigeminal nerve) → Maxillary division → nasopalatine nerves & sphenopalatine ganglion

Question 5

SNS stimulation of nose results in:

Answer 5

vasoconstriction & shrinkage of nasal tissue

Question 6

PSNS stimulation of nose results in:

Answer 6

seen with general anesthesia

engorgement of blood vessels
↑ risk of bleeding during airway manipulation

Question 7

sensory innervation of tonsils, roof of pharynx, underside of soft palate

Answer 7

CN IX (Glossopharyngeal)

Question 8

sensory innervation of the tongue (Anterior 2/3)

Answer 8

lingual nerve

CN V → Mandibular division → Lingual nerve

Question 9

sensory innervation of the tongue (Posterior 1/3)

Answer 9

CN IX (Glossopharyngeal)

Question 10

innervation of salivary glands

Answer 10

CN VII (Facial)

Question 11

motor innervation of facial expression

Answer 11

CN VII (Facial)

Question 12

motor innervation of stylohyoid laryngeal muscle

Answer 12

CN VII (Facial)

Question 13

motor innervation to tongue

Answer 13

CN XII (Hypoglossal)

Question 14

damage to CN XII can result in

Answer 14

CN XII (Hypoglossal)
Loss of motor innervation to the tongue. 
Tongue can fall back and obstruct airway.

Question 15

sensory innervation of larynx from epiglottis to vocal cords

sensation ABOVE cords

Answer 15

internal branch of Superior Laryngeal Nerve (SLN)

CN X (Vagus) → Superior Laryngeal Nerve → Internal branch

Question 16

external branch of SLN

Answer 16

motor innervation to cricothyroid muscle

Question 17

sensory innervation of larynx BELOW vocal cords

Answer 17

Recurrent Laryngeal Nerve (RLN)

CN X (Vagus) → Recurrent Laryngeal Nerve

Question 18

recurrent laryngeal nerve (RLN)

Answer 18

Motor: innervates ALL muscles of the larynx except for the cricothyroid muscle

Sensory:
to larynx below cords and upper esophagus

Anatomy:
Right side - leaves Vagus at the level of the subclavian
Left side - leaves Vagus at the level of the aortic arch
*runs in the groove alongside trachea

Question 19

internal branch of the SLN

Answer 19

sensory to:

1. lower pharynx
2. underside of epiglottis
3. larynx ABOVE the cords.

Question 20

injury to Superior Laryngeal Nerve

Answer 20

Unilateral: minimal effect

Bilateral: hoarseness, vocal tiring

Question 21

injury to Recurrent Laryngeal Nerve

Answer 21

Unilateral: hoarseness

Bilateral:

• Acute: stridor, respiratory distress [unopposed tension of the cricothyroid muscle]
• Chronic: aphonia

Question 22

injury to CN X

Answer 22

(Vagus)

Affects both SLN and RLN

*flaccid, midpositioned cords resulting in aphonia

Question 23

pharyngeal plexus

Answer 23

1. pharyngeal branches from glossopharyngeal (CN IX)
2. pharyngeal branch of Vagus (CN X)
   [except stylopharyngeus]
3. branches from external laryngeal nerve
4. sympathetic fibers from cervical ganglion

Question 24

CN V: Trigeminal

Answer 24

Motor:
jaw movement

Sensory:
sensation of face, cheeks, taste

Question 25

CN IX: Glossopharyngeal

Answer 25

Motor:
swallow & stylopharyngeus

Sensory:
taste

Question 26

CN X: Vagus

Answer 26

Motor:

• upper airway muscles (except stylopharyngeus)
• cricothyroid muscle

Sensory:
of airway/larynx/trachea

Question 27

CN VII: Facial

Answer 27

Motor:
facial expression

Sensory:
taste

Question 28

CN XI: Spinal Accessory

Answer 28

Motor:

shoulder / neck movement

Question 29

CN XII: Hypoglossal

Answer 29

Motor:

tongue movement

Question 30

carina has ___ innervation

Answer 30

rich

Question 31

unilateral SLN injury effect on vocal cords

Answer 31

minimal effects

Question 32

bilateral SLN injury effect on vocal cords

Answer 32

hoarseness, vocal tiring

Question 33

unilateral RLN injury effect on vocal cords

Answer 33

hoarseness

Question 34

bilateral RLN injury effect on vocal cords

acute vs chronic

Answer 34

Acute: stridor, respiratory distress d/t unopposed cricothyroid tension

Chronic: aphonia