Respiratory Anatomy

Question 1

Name the 5 INTRINSIC muscles of the airway

Answer 1

Cricothyroid
Thyroarytenoid
Lateral cricoarytnoid
Posterior cricoarytnoid
Vocalis

Question 2

What does the Cricothyroid do

Answer 2

Elongates (tenses cords)
“Cords Tense”

Question 3

What does the thyroarytenoid muscle do?

Answer 3

Shortens (relaxes cords) ~ muscles shorten
“They relax”
This leads to ADDuction of cords

Question 4

What does the posterior cricoarytnoid muscles do

Answer 4

ABDucts vocal cords
“Please come apart”

Question 5

What do the lateral cricoarytenoid muscles do?

Answer 5

ADDuct the vocal cords
“Let’s Close Airway”

Question 6

What is cranial nerve 5

Answer 6

Trigeminal Nerve

Question 7

How many branches are there to the trigeminal nerve

Answer 7

3
Ophthalmic nerve (V1)
Maxillary Nerve (V2)
Mandibular (V3)

Question 8

What does the opthalamic nerve innervate?

Answer 8

First 1/3 of the nasal septum

Question 9

What does the maxillary nerve (V2) innervate?

Answer 9

Turbinates, posterior 2/3 of the nasal septum

Question 10

What does the mandibular nerve innervate?

Answer 10

Anterior 2/3 of the tongue

Question 11

What does the glossopharyngeal nerve innervate?

Answer 11

Posterior 1/3 of the tongue, oropharynx, vallecula, and anterior side of epiglottis

Question 12

What cranial nerve is the glossopharyngeal nerve

Answer 12

9

Question 13

What is cranial nerve 10?

Answer 13

The Vagus nerve

Question 14

What two nerves originate from the Vagus?

Answer 14

Superior laryngeal
Recurrent laryngeal

Question 15

What does the superior laryngeal nerve divide into?

Answer 15

Internal branch (pierces the thyrohyoid membrane
External branch

Question 16

What does the internal branch of the superior laryngeal nerve innervate?

Answer 16

Sensory.
Posterior side of the epiglottis to the level of the vocal cords

Question 17

What does the external branch of the superior laryngeal nerve innervate?

Answer 17

Cricothyroid muscle

Question 18

Acute injury to the superior laryngeal nerve causes what?

Answer 18

Hoarseness

Question 19

What does the recurrent laryngeal nerve innervate?

Answer 19

Below the level of the vocal cords to the trachea

Question 20

What happens with injury to the recurrent laryngeal nerve?

Answer 20

Unilateral: hoarseness
Bilateral: strider/resp distress

Question 21

Where do the recurrent laryngeal branches loop?

Answer 21

Right: under the right subclavian artery
Left: under the aorta (this is more susceptible to injury)

Question 22

What are the three cranial nerves that innervate the upper airway?

Answer 22

Trigeminal
Glossopharyngeal
Vagus

Question 23

What 3 nerves must you block for an awake fiberoptic?

Answer 23

Glossopharyngeal
Superior laryngeal
Recurrent laryngeal

Question 24

Where is your site of injection for a glossopharyngeal block?

Answer 24

Base of the palatoglossal arch (tonsillar pillar)

Must repeat on the other side!

Question 25

Where is your site of injection for a superior laryngeal block?

Answer 25

Greater Cornu of the hyoid bone Must repeat on the other side!

Question 26

Where is your site of injection for a recurrent laryngeal block?

Answer 26

Puncture the Cricothyroid membrane and advance in a CAUDAL direction Coughing is good!

Question 27

Where does the ADULT airway lie?

Answer 27

C4-C6

Question 28

What are 3 functions of the larynx?

Answer 28

Airway protection, respiration, and phonation

Question 29

How many cartilages does the larynx have?

Answer 29

9 (3 PAIRED cartilages) 3 unpaired cartilages

Question 30

What are the 9 cartilages of the airway?

Answer 30

Paired: arytenoids, cuneiform, corniculate Unpaired: thyroid, epiglottis, cricoid

Question 31

What is the narrowest region of the airway in adults?

Answer 31

The glottis opening

Question 32

What is the narrowest region of the airway in kids?

Answer 32

It’s tricky! Narrowest fixed region: cricoid ring Narrowest dynamic region: vocal cords

Question 33

What is the laryngospasm reflex pathway?

Answer 33

Afferent limb: internal branch of the SLN Efferent limb: external branch of the SLN or recurrent laryngeal nerve branches (thyroarytenoid and lateral cricoarytenoid branches)

Question 34

What are some pre-anesthetic risk factors to laryngospasm

Answer 34

Resp infections Second-hand smoke Reactive airway disease Age < 1 year

Question 35

What are some intra-anesthetic risk factors for laryngospasm?

Answer 35

Light anesthesia Saliva/blood Hyperventilation/hypocapnia Surgical procedures of the airway (tonsils, palate, nasal/sinus, laryngoscopy)

Question 36

How do you break a laryngospasm

Answer 36

1. 100% FiO2 2. Remove stimulation 3. Deepens anesthetic (prop) 4. CPAP 15-20 (with larsens) 5. Administer Sux (IM 4mg/kg; IV 1mg/kg)

Question 37

What is Larsen’s maneuver?

Answer 37

Firm pressure on laryngospasm notch. Pushes mandible anteriorly and causes patient to sigh

Question 38

What is a valsalva’s maneuver?

Answer 38

Exhalation against a closed glottis (coughing, bucking, bearing down) Increases pressure to in thorax, abd, and brian

Question 39

What is Muller’s maneuver?

Answer 39

Inhalation against a closed glottis (patient bites ETT) Negative pressure pulmonary edema due to subatmospheric pressure in thorax

Question 40

What causes obstruction at the level of the tongue?

Answer 40

Genioglossus muscle relaxation

Question 41

What causes obstruction at the level of the soft palate?

Answer 41

Tensor palatine muscle relaxation

Question 42

Where does the trachea begin and end?

Answer 42

Begins C6 Ends T5 (carina)

Question 43

Where is the carina and what does it correspond with?

Answer 43

T5 and it corresponds with the Angle of Louis

Question 44

What allows movement between cells?

Answer 44

Pores of Kohn

Question 45

What do type 1 pneumocytes do?

Answer 45

Gas exchange Cover 80% of alveolar surface

Question 46

What do type 2 pneumocytes do?

Answer 46

Produce surfactant

Question 47

What does type 3 pneumocytes do?

Answer 47

They are macrophages They fight lung infection and produce inflammatory responses

Question 48

Are neutrophils present in the airway?

Answer 48

They are present in patients who are smokers or with acute lung injury.

Question 49

What is the distance from the incisors to the larynx?

Answer 49

13 cms

Question 50

What is the distance from the larynx to the carina?

Answer 50

13 cms

Question 51

What is the tot distance from the incisors to the carina

Answer 51

26 cm Think the entire length of an ETT

Question 52

What increases as the airway progresses?

Answer 52

Number of airways Total cross-sectional area

Question 53

What decreases as the airway progresses (I.e goes from the trachea to the bronchioles)

Answer 53

Airway velocity Airway cartilage Goblets cells Ciliated cells