Airway Anatomy

Question 1

What is the function of the intrinsic muscles?

Answer 1

Phonation and vocal cord movement

Question 2

What is the function of the extrinsic muscles?

Answer 2

support the larynx inside the neck and assist with swallowing

Question 3

The true vocal cords are innervated by which nerve?

Answer 3

None. They are ligaments, not muscles

Question 4

The true vocal cords attach to the _____ anteriorly and the _____ posteriorly

Answer 4

Thyroid

Arytenoids

Question 5

Identify the pink muscle. List its action and innervation.

Answer 5

Cricothyroid

Elongates (tenses) vocal cords

External SLN

Question 6

Identify the green muscle.

List its action and innervation.

Answer 6

Thyroarytenoid

Shortens (relaxes) vocal cords

ADDucts the vocal folds (closes the glottis)

RLN

Question 7

Identify the green muscle.

List its action and innervation.

Answer 7

Thyroarytenoid

Shortens (relaxes) vocal cords

ADDucts the vocal folds (closes the glottis)

RLN

Question 8

Identify the purple muscle.

List its action and innervation.

Answer 8

Vocalis

Shortens (relaxes) vocal cords

RLN

Question 9

Identify the blue muscle.

List its action and innervation.

Answer 9

Lateral Cricoarytenoid

ADDucts vocal folds (closes glottis)

RLN

Question 10

Identify the orange muscle.

List its action and innervation.

Answer 10

Posterior cricoarytenoid

ABDucts the vocal folds (opens the glottis)

Question 11

Identify the structure in the green box.

Answer 11

Posterior cricoarytenoid

Question 12

Identify the structure in the purple box.

Answer 12

Cuneiform Cartilage

Question 13

Identify the structure in the blue box

Answer 13

Corniculate Cartilage

Question 14

Identify the structures in pink.

List their function and innervation.

Answer 14

Interarytenoids (transverse and oblique)

Closes posterior commissure of the glottis

RLN

Question 15

Identify the structure indicated by yellow arrows.

List its function and innervation.

Answer 15

Aryepiglottic

Closes the laryngeal vestibule

RLN

Question 16

Which muscle(s) relax/shorten the vocal ligaments?

Answer 16

Vocalis

Thyroarytenoid (“They Relax”)

Question 17

Which muscle(s) tense/elongate the vocal ligaments?

Answer 17

Cricothyroid

“Cords Tense”

Question 18

Which muscle(s) ADDuct the vocal folds?

What is the outcome of this?

Answer 18

Thyroarytenoid

Lateral Cricothyroid

Narrowing the glottis

Question 19

Which muscles function as sphincters?

Answer 19

Aryepiglottic (Closes laryngeal vestibule)

Interarytenoids (Closes posterior commissure of glottis)

Question 20

Which muscles elevate the larynx?

Which muscles depress the larynx?

Answer 20

Question 21

Which muscle has both intrinsic and extrinsic actions?

Answer 21

Cricothyroid Mm

Question 22

Which muscles ABDuct the vocal cords?

Answer 22

Posterior Crico Arytenoids

“Please Come Apart”

Question 23

Which muscles ADDucts the vocal cords?

Answer 23

Lateral CricoArytenoid

(Let’s Close the Airway)

Question 24

The internal branch of the SLN is a _______ nerve.

The external branch of the SLN is a ______ nerve.

Answer 24

Sensory

Motor

Question 25

What does the internal branch of the SLN innervate?

Answer 25

provides **sensory** to the posterior side of the epiglottis to the top side of the vocal cords NO MOTOR FUNCTION

Question 26

What does the external branch of the SLN innervate?

Answer 26

Provides motor innervation to the cricothyroid mm. NO SENSORY FUNCTION

Question 27

The nerves of the airway arise from which three cranial nerves?

Answer 27

Trigeminal (V) Glossopharyngeal (IX) Vagus (XII)

Question 28

Identify the nerves marked.

Answer 28

These are the branches of the trigeminal nerve (yellow): Purple: ophthalmic Orange: Maxillary Blue: Mandibular

Question 29

What does the lingual nerve innervate? Trace its origin.

Answer 29

Sensory: Anterior ⅔ of the tongue Trigeminal → Mandibular → Lingual

Question 30

What does the sphenopalatine nerve innervate? Trace its origin.

Answer 30

SENSORY; Turbinates and posterior ⅔ of nasal septum Trigeminal → Maxillary → Sphenopalatine

Question 31

The trigeminal nerve provides _____ innervation to the face

Answer 31

SENSORY

Question 32

What does the anterior ethmoidal nerve innervate? Trace its origin.

Answer 32

SENSORY: Nares and anterior ⅓ of nasal septum Trigeminal → Ophthalmic → Anterior Ethmoidal

Question 33

The gag reflex is completed by two nerves: Afferent limb: Efferent limb:

Answer 33

Afferent: Glossopharyngeal (responds to soft palate stimulation) Efferent: Vagus (causes pharyngeal constriction)

Question 34

Which nerves provides sensory innervation to the posterior ⅓ of the tongue?

Answer 34

Glossopharyngeal

Question 35

Which nerve provides sensory innervation to the oropharynx and valecula?

Answer 35

Glossopharnygeal

Question 36

The Vagus Nerve branches into the:

Answer 36

Superior Laryngeal Recurrent Laryngeal

Question 37

What is the function of the internal branch of the SLN?

Answer 37

SENSORY ONLY Posterior side of the epiglottis to the level of the vocal cords

Question 38

What is the function of the external branch of the SLN?

Answer 38

MOTOR Cricothyroid Muscles

Question 39

What would happen if the trunk of the SLN or its external branch are injured?

Answer 39

Hoarseness, but no respiratory distress

Question 40

Which nerve provides sensory innervation below the level of the folds?

Answer 40

The recurrent laryngeal

Question 41

Both recurrent laryngeal nerves branch off of the \_\_\_\_\_\_\_. The R RLN loops under the \_\_\_\_\_\_ The L RLN loops under the \_\_\_\_\_\_

Answer 41

Vagus Subclavian Artery Aortic Arch

Question 42

Which RLN is more susceptible to injury?

Answer 42

The Left, because it is in the thorax

Question 43

What happens when unilateral RLN damage occurs?

Answer 43

Ipsilateral (same side) paralysis of ABDuctor motion cause unopposed ADDuctor motion, and that side will NOT OPEN

Question 44

In bilateral recurrent laryngeal nerve injury, why do the vocal cords snap shut?

Answer 44

The ADDucting motion of the posterior cricoarytenoids is unopposed, and causes the cords to snap shut

Question 45

Tongue movement is provided by which nerve?

Answer 45

Hypoglossal (CN 12)

Question 46

What tends to cause L RLN unilateral injury?

Answer 46

Stuff in the thorax: L Atrial Enlargement (from mitral stenosis) Aortic Arch Aneurysm PDA ligation Thoracic Tumor

Question 47

Which muscle serves as the “tuning fork” of the larynx?

Answer 47

Cricothyroid

Question 48

Which RLN is injured in this patient?

Answer 48

The Left RLN