Airway Anatomy

Question 1

Laryngeal muscles are classified as ______ or _______

Answer 1

intrinsic or extrinsic

Question 2

Intrinsic laryngeal muscles participate in?

Answer 2

Phonation and control of the vocal cords (tensions and position)

Question 3

Extrinsic Laryngeal muscles participate in?

Answer 3

Support the larynx inside the neck and assist with swallowing

Question 4

True or False: The true vocal cords are ligaments and are, therefore, not innervated.

Answer 4

True

Question 5

What do the true vocal cords attach to?

Answer 5

Attach to the thyroid cartilage anteriorly and the arytenoids posteriorly.

Question 6

What muscles adjust the length or tension of the vocal ligaments? Either tense and relax.

Answer 6

Cricothyroid = elongates (tenses)
Vocalis = shortens (relaxes)
Thyroarytenoid = shortens (relaxes)

Question 7

Function and Innvervation of the Cricothyroid Muscle

Answer 7

Intrinsic Laryngeal muscle. Elongates (tenses) vocal cords. [Does have an extrinsic function. During swallowing, pulls anterior region of cricoid cartilage down]

Innervated by External Superior Laryngeal Nerve

Question 8

Function and Innvervation of the Vocalis Muscle

Answer 8

Intrinsic Laryngeal muscle. Shortens (relaxes) vocal cords.

Innervated by the Recurrent Laryngeal Nerve

Question 9

Function and Innvervation of the Thyroarytenoid Muscle

Answer 9

Intrinsic Laryngeal muscle.

Shortens (relaxes) vocal cords.
Adducts vocal folds (closes glottis)

Innervated by the Recurrent Laryngeal Nerve

Question 10

All intrinsic laryngeal muscles are innervated by _________ except ________ muscles

Answer 10

all innervated by the recurrent laryngeal nerve except the cricothyroid muscles

Question 11

What intrinsic laryngeal muscles adduct or abduct the vocal folds (glottic diameter)

Answer 11

Thyroartytenoid (aDducts)
Lateral cricoarytenoid (aDducts, Lets Close)
Posterior cricoarytenoid (aBducts, Please Come Apart)

Question 12

Function and Innvervation of the Lateral Cricoarytenoid

Answer 12

ADDucts the vocal folds (narrows glottis)

Recurrent Laryngeal Nerve

Question 13

Function and Innvervation of the Posterior Cricoarytenoid

Answer 13

ABducts the vocal folds (widens glottis)

Recurrent Laryngeal Nerve

Question 14

Function and Innvervation of the Aryepiglottic muscle

Answer 14

Closes laryngeal vestibule

Recurrent Laryngeal Nerve

Question 15

Function and Innvervation of the Interarytenoid muscle

Answer 15

Closes posterior commissure of glottis

Recurrent Laryngeal Nerve

Question 16

Name the extrinsic laryngeal muscles the depress the larynx

Answer 16

Omohyoid
Sternohyoid
Sternothyroid

Question 17

Name the extrinsic laryngeal muscles the elevate the larynx

Answer 17

Digastric (ant and posterior belly)
Mylohyoid
Stylohyoid
Thyrohyoid

Question 18

What 3 cranial nerves innervate the upper airway?

Answer 18

Trigeminal - CN 5
-V1: opthalamic, V2: maxillary, and V3: mandibular
Glossopharyngeal CN 9
Vagus CN 10

Question 19

V3: The mandibular branch of the trigeminal provides motor innervation to?

Answer 19

Muscles of mastication

Question 20

What cranial nerve provides motor innervation to the tongue?

Answer 20

CN 12 - Hypoglossal

Question 21

CN 9 - Glossopharyngeal relays sensation information from what areas in the upper airway?

Answer 21

Soft Palate
Oropharynx
Tonsils
Posterior 1/3 of Tongue
Vallecula
Anterior side of epiglottis
Afferent limb of gag reflex

Question 22

If the patient gags during intubation, what nerve sensed that stimulation

Answer 22

Glossopharyngeal CN 9

Question 23

The Glossopharyngeal CN 9 participates in what two motor functions

Answer 23

Participates in swallowing and phonation

Question 24

Trigeminal V1: Ophthalmic nerve has what sensory function

Answer 24

Nares and Anterior 1/3 of nasal septum

Question 25

Trigeminal V2: Maxillary (sphenopalatine) nerve has what sensory function

Answer 25

Turbinates and septum

Question 26

Trigeminal V3: Mandibular nerve has what sensory function? What motor function?

Answer 26

Sensation: Anterior 2/3 of tongue Motor: Mastication

Question 27

The Vagus Nerve - CN 10, divides into what branches.

Answer 27

Superior Laryngeal Nerve -internal -external Recurrent Laryngeal Nerve

Question 28

What are the sensory and motor functions of the Internal branch of the Superior Laryngeal Nerve

Answer 28

Motor: NO MOTOR Sensory: Posterior side of epiglottis to the level of the vocal cords

Question 29

What are the sensory and motor functions of the External branch of the Superior Laryngeal Nerve

Answer 29

Motor: Cricothyroid muscles (tense vocal cords) Sensory: No Sensory

Question 30

What are the Sensory and Motor functions of the Recurrent Laryngeal Nerve?

Answer 30

Motor: ALL intrinsic laryngeal muscles Except Cricothyroids Sensory: Below the level of vocal cords to the trachea

Question 31

At the level of the ______, the Superior Laryngeal Nerve branches into the internal and external.

Answer 31

Hyoid

Question 32

The internal branch of the superior laryngeal nerve penetrates what membrane?

Answer 32

Thyrohyoid Membrane

Question 33

The External Branch of the Superior Laryngeal Nerve innervates?

Answer 33

Cricothyroid Muscle

Question 34

Where do the recurrent laryngeal nerves branch off the vagus nerve?

Answer 34

Inside the thorax

Question 35

The Right Recurrent Laryngeal Nerve loops under what structure to reach the larynx

Answer 35

Loops under the right subclavian artery

Question 36

The Left Recurrent Laryngeal Nerve loops under what structure to reach the larynx

Answer 36

Loops under the aortic arch

Question 37

Which recurrent laryngeal nerve is more susceptible to injury? Why?

Answer 37

Due to its position under the aortic arch, the left RLN is more likely to be injured

Question 38

Bilateral recurrent laryngeal nerve injury can be caused by?

Answer 38

External pressure from ETT / LMA Surgery: thyroid/parathyroid Neck stretching Neck tumor

Question 39

Left recurrent laryngeal nerve injury can be caused by?

Answer 39

PDA ligation Left Atrial Enlargement (mitral stenosis) Aortic Arch dissection Thoracic tumor

Question 40

The trachea is approximately how long in adults?

Answer 40

~10-20 cm