Respiratory - Airway Anatomy Flashcards
What nerves provide motor innervation to the larynx?
External SLN, RLN
What nerve is responsible for motor function of the cricothyroid muscle?
external superior laryngeal nerve
What nerves provide sensory innervation to the larynx?
internal SLN, RLN
Sensory innervation above the vocal cords is provided by which nerve?
internal SLN
Sensory innervation below the vocal cords is provided by which nerve?
RLN
Which vocal cords attach anteriorly to the thyroid cartilage and posteriorly to the arytenoid cartilage?
true vocal cords
Which intrinsic muscles of the larynx adjust length (tension) of the vocal ligaments? (3)
cricothyroid, vocalis, thyroarytenoid
Which intrinsic muscle of the larynx elongates (tenses) the vocal ligaments?
cricothyroid
The cricothyoid muscle is innervated by which nerve?
external SLN
Which intrinsic muscles of the larynx shortens (relaxes) the vocal ligaments?
vocalis, thyroarytenoid
The vocalis and thyroarytenoid muscles are innervated by which nerves?
RLN
Which intrinsic muscles of the larynx abduct or adduct the vocal folds?
thyroarytenoid, lateral cricoarytenoid, posterior cricoarytenoid
Which intrinsic muscles of the larynx adduct the vocal folds?
thyroarytenoid, lateral cricoarytenoid
Which intrinsic muscles of the larynx abduct the vocal folds?
posterior cricoarytenoid
Which nerve innervates the thyroarytenoid muscle?
RLN
Which nerve innervates the lateral cricoarytenoid muscle?
RLN
Which nerve innervates the posterior cricoarytenoid muscle?
RLN
Which intrinsic muscle of the larynx closes the laryngeal vestibule?
aryepiglottic
Which intrinsic muscle of the larynx closes the posterior commissure of the glottis?
interarytenoid
Which nerve innervates the aryepiglottic muscle?
RLN
Which nerve innervates the interarytenoid muscle?
RLN
What does the CricoThyroid muscle do to the vocal cords?
“Cords Tense”
What does the ThyroaRytenoid muscle do to the vocal cords?
“They Relax”
What does the Posterior CricoArytenoid muscle do to the vocal cords”
“Please Come Apart” - abduct
What does the Lateral CricoArytenoid muscle do to the vocal cords?
“Lets Close Airway” - adduct
Do the extrinsic or intrinsic muscle of the larynx allow movement for breathing, swallowing, and phonation?
extrinsic
How do the Stylohyoid, Geniohyoid, Mylohyoid, Throhyoid, Digastric, and Stylopharyngeus move the larynx?
elevate the larynx
How do the Omohyoid, Sternohyoid, and Sternothyroid move the larynx?
depresses the larynx
What nerves provide sensory innervation to the airway?
trigeminal (CN 5), glossopharygeal (CN 9), SLN, RLN
What nerve provides sensation to the nares and anterior 1/3 of the nasal septum?
V1: opthalmic
What nerve provides sensation to the turbinates and septum?
V2: maxillary
What nerve provides sensation to the anterior 2/3 of the tongue?
V3: mandibular
What nerve provides sensory innervation to the soft palate, oropharynx, tonsils, posterior 1/3 of tongue, vallecula, and anterior side of epiglottis?
glossopharyngeal
What nerve is the afferent limb of the gag reflex?
glossopharyngeal
Which branch of the SLN does not have sensory innervation?
external SLN
Which nerve provides sensory innervation to the posterior side of the epiglottis?
internal SLN
Which nerve provides sensory innervation below the vocal cords to the trachea?
RLN
What nerve provides motor innervation to all intrinsic muscle of the larynx except the cricothyroid?
RLN
Where does the SLN divide into internal and external branches?
hyoid
Which branch of the SLN enters the cricothyroid membrane?
external
Injury to the trunk of the SLN or the external branch leads to what symptom?
hoarseness
The SLN and RLN are branches of which nerve?
vagus
Damage to the aortic arch can damage which branch of the vagus nerve?
RLN
Which branch of the RLN is more susceptible to injury?
left
What does bilateral injury to the RLN cause?
paralysis of vocal cord abductors
Bilateral injury to the RLN leads to which muscles being unopposed?
cricothyroid muscles (“Cords Tense”)
What are two symptoms of bilateral RLN injury?
stridor and respiratory distress
Does unilateral paralysis of a branch of the RLN cause respiratory distress?
no
Which procedures or situations lead to potential RLN damage? (5)
excessive pressure (ETT cuff or LMA), thyroid sx, parathyroid sx, neck stretching, tumor
What procedures risk damage to the left RLN?
PDA ligation, mitral stenosis, aortic aneurysm, thoracic tumor
What is the landmark to blocks the SLN?
greater cornu of hyoid
How do you block the SLN?
1mL LA above thyrohyoid membrane, 2mL beneath thyrohyoid membrane
What indicates your needle is too deep during SLN block?
air aspiration
What is the key landmark for a transtracheal block?
cricothyroid membrane
How do you perform a transtracheal block?
insert the needle in the cricothyroid membrane in a caudal direction. As the person takes a big breath in inject 2-3mL. Pt coughs and LA sprays the vocal cords from the inferior side.
Where is the needle inserted for a glossopharyngeal block?
base of palatoglossal arch
Inadvertently injecting LA into the carotid artery during glossopharyngeal block will manifest as what symptom?
seizures
What are the paired laryngeal cartilages?
corniculate, cuneiform, and arytenoid
Rheumatoid arthritis and SLE can significantly restrict which laryngeal cartilages?
arytenoid
What are the unpaired laryngeal cartilages?
epiglottis, thyroid, cricoid
What provides the mechanical barrier between the laryngeal opening and the pharynx?
epiglottis
What ligament connects the epiglottis to the thyroid cartilage?
thyroepiglottic
What is the largest cartilage in the larynx?
thyroid cartilage
What is the most caudal part of the larynx?
cricoid cartilage
What cartilage forms the only complete ring in the airway?
cricoid cartilage
What is the narrowest part of the airway in adults and peds?
Adults: vocal cords. Peds: cricoid ring
What are the anterior ligaments of the larynx?
thyrohyoid and cricothyroid
What is the only bone in the body that does not communicate with another bone?
hyoid
What membrane is emergently punctured to secure the airway?
cricothyroid
What are potential complications of laryngospasm? (5)
Complete airway obstruction, negative pressure pulmonary edema, gastric aspiration, cardiac arrest, and death
Which population is laryngospasm most common?
children < 1
What are risk factors for laryngospasm? (5)
active or recent URI, second hand smoke, RAD, GERD, age < 1
What are intraoperative risk factors for laryngospasm?
light anesthesia and airway manipulation, secretions, hyperventilation, hypocapnia, tonsillectomy, adenoidectomy, nasal/sinus sx, laryngoscopy, bronchoscopy, palatal
What are the afferent and efferent branches of laryngospasm?
afferent: internal SLN. Efferent: external SLN and RLN
What membrane is responsible for tensing the vocal cords during laryngospasm?
cricothyroid
What membrane is responsible for adduction of the vocal cords during laryngospasm?
lateral cricoarytenoid and thyroarytenoid
What are signs of laryngospasm?
inspiratory stridor, suprasternal and supraclavicular retraction, rocking horse chest wall, diaphragmatic excursion, lower rib flailing
How much CPAP reduces the risk of laryngospasm?
5-10 cmH2O
How do we treat laryngospasm?
100% FiO2, remove noxious stimuli, deepen, CPAP 15-20 cmH2O
What is the maneuver to open the airway during laryngospasm?
larson
What is the IV dose of Succ for adults and peds for laryngospasm?
Adults/children: 1mg/kg. Neonate/infant: 2mg/kg
What is the IM dose of Succ for adults and peds for laryngospasm?
Adults/children: 4mg/kg. Neonate/infant: 5mg/kg
What route of administration has the fastest onset of action for laryngospasm treatment with succ?
submental
What is firm pressure to the laryngospasm notch called?
Larsons maneuver
Where is the laryngospasm notch located?
behind the earlobe
What are the borders of the laryngospasm notch? Posterior, anterior and superior
posterior - mastoid process
anterior - ramus of mandible
superior - skull base
What is the goal of the Larson maneuver?
break a laryngospasm by causing the pt to sigh
How long is the Larson maneuver performed?
3-5 seconds, released for 5-10 seconds. repeat
What is exhalation against a closed glottis?
valsalva maneuver
What are the risk of the valsalva maneuver?
increased pressure in the thorax, abdomen and brain
What is inhalation against a closed glottis?
mullers maneuver
what is the risk of mullers maneuver?
negative pressure pulmonary edema
What are the borders of the upper airway?
mouth/nares to the cricoid cartilage
What is the primary function of the upper airway?
warm and humidify air, filter, prevent aspiration
How do we replace the function of the upper airway in an intubated patient?
HME to warm, humidify and filter. ETT cuff to prevent aspiration
What creates the negative pressure to draw air into the lungs?
diaphragmatic contraction and chest wall expansion
What conditions reduce the diameter of the pharynx and impair patency? (2)
reduced pharyngeal dilator muscle tone
negative pressure during inspiration
What conditions reduce the overall size of the pharynx and impair patency? (5)
obesity, large tongue, hypertrophy of tonsils/adenoids, small craniofacial structures, craniofacial deformity
What muscle opens the nasopharynx?
tensor palatine (soft palate)
What muscle opens the oropharynx?
genioglossus (tongue)
What muscle opens the hypopharynx?
hyoid muscles (epiglottis)
Select (state) the three muscles that dilate the muscles of the pharynx?
tensor palatine, genioglossus, hyoid muscles
What are the borders of the lower airway?
trachea to the alveoli
Where does the trachea begin and end?
C6 - T4/5 (carina)
What type of cells make up the trachea?
ciliated columnar epithelium
What nerve provides sensory innervation to the trachea?
vagus
The inferior thyroid artery, superior thyroid artery, bronchial artery, and internal thoracic artery provide blood supply to what lower airway structure?
trachea
What anatomical structure corresponds to the Angle of Louis?
trachea
What type of cells make up the trachea?
ciliated columnar epithelium
State the length and angle of the right mainstream bronchi.
2.5cm long, 25 degree angle
State the length and angle of the left mainstream bronchi.
5cm long, 45 degree angle
What type of cells make up the mainstream bronchi?
coboidal epithelium
What type of cells make up the alveoli?
squamous epithelium
What allows air movement between alveoli?
pores of kohn
Describe type 1 cells.
surface area for gas exchange, flat squamous cells, 80% of alveolar surface area, form tight junctions
Describe type 2 cells
produce surfactant***, capable of division, produce type 1 cells
What do type 3 cells do?
fight lung infection and produce inflammatory mediators
When are neutrophils present in alveoli?
smokers and acute lung injury
What is the distance from the incisors to larynx?
13cm
What is the distance from the larynx to carina?
13cm
What makes the distance from the incisors to the carina change?
Neck flexion and extension. (mainstem or extubation above the cords)
As the airway divides/bifurcates, what characteristics of the airway increase? (3)
number of airways, cross sectional area, muscular layer
As the airway divides/bifurcates, what characteristics of the airway decrease? (4)
airflow velocity, amount of cartilage, goblet cells, ciliated cells
What cells produce mucus and which ones clear mucus?
goblet produce, ciliated clear
What structures are included in the conducting zones of the airway? (6)
trachea, mainstem bronchi, lobar bronchi, small bronchi, bronchioles, terminal bronchioles
What structures are included in the respiratory zones of the airway? (3)
respiratory bronchioles, alveolar ducts, alveolar sacs
