Airway/Larynx/Swallowing Flashcards
What region of obstruction is characteristic of inspiratory stridor?
Supraglottic/glottic
What region of obstruction is characteristic of biphasic stridor?
Subglottic
What region of obstruction is characteristic of expiratory stridor?
Tracheobronchial
How do neonates breathe?
Obligate nasal breathers
What is the typical presentation of nasal foreign bodies in young children?
Unilateral malodorous rhinorrhea
What is the function of the larynx?
Conduit for ingested material into esophagus, protection of lower airways from aspiration, and intricate structures utilized in phonation
What is the difference in position between the adult and neonatal larynx?
Neonatal larynx is at the level of C2 and contacts the palate and epiglottis directly (provides airway protection and helps with feeding), adult larynx lies at the C7 vertebral body
What nerve provides sensory innervation tot he larynx? Muscle innervation?
Sensory: superior laryngeal
Motor: recurrent laryngeal
What is the pathway of the recurrent laryngeal nerve?
It travels into the upper thorax from the skull base, loops around cardiovascular structures, and then goes back up to innervvate vocal cords
What is the supraglottis? Glottis? Subglottis?
Supraglottis = area above vocal cords
Glottis = vocal cords
Subglottis = cricoid cartilage
What is the function of the cricothyorid muscle?
Laryngeal tilting which stretches and tightens the vocal folds (inflection of voice)
What is the function of the posterior cricoarytenoid muscle?
Actively abducts the larynx
What is the laryngeal adductor reflex?
A reflux for adductor stimulus that leads to rapid closure of the laryngeal muscles to prevent penetration and aspiration into the airway
Why is left vocal cord paralysis more common than right?
The left recurrent laryngeal nerve has a long course around the heart and is at high risk for injury
What is the most common cause of stridor in neonates?
Laryngomalacia - immature supraglottic opening at birth (omega shaped epiglottis)
What is subglottic stenosis?
Stenosis of the subglottic ring that can be congenital or acquired during intubation injury
What is the most common subglottic tumor in neonates?
Subglottic hemangioma
What is the presentation of subglottic hemangioma?
Usually presents with cutaneous hemangioma, worsens with crying, improves with calm and steroids, often mistaken for croup.
Treated with propanolol for 12 months
What is a tracheosophageal fistula?
A congenital connection between the trachea and esophagus and is associated with esophageal atresia
What is complete tracheal rings?
Results from failure of development of the trachealis muscle posteriorly, leading to a stenotic and rigid fully enclosed ring. Highly associated with cardiac anomalies.
What is the epiglottis?
Laryngeal cartilage in oropharynx guarding the entry to larynx
What is a valleculae?
Recesses in oropharynx anterior to the epiglottis on either side of the glosso-epiglottic fold at the back of the tongue
What is the piriform recess?
Interval on each side of the laryngopharynx between the cricoid cartilage and posterior edge of thyroid cartilage of larynx
What are vestibular folds?
False vocal folds that overlay true vocal folds
What is the vestibule of the larynx?
Entryway into larynx between aryepiglottic folds above vestibular (false) folds below
What is the ventricle of the larynx?
Compartment on each side between the false vocal cords above and the true vocal cords below
What is the rima glottidis?
The space between the two vocal cords
What is the quadrangular membrane?
Connective tissue wall of the vestibule (lower edge forms false vocal cords)
What is the triangular membrane?
Conus elasticus bounding the infraglottic cavity, forms the cricothyroid ligament
What are vocal ligaments?
Superior portion of the conus elasticus (focal fold is what vibrates)
What is the function of the posterior cricoarytenoid?
Rotates the arytenoid cartilages laterally to pull the cords apart (abduction) during inspiration
only muscle that abducts
What is the function of the lateral cricoarytenoid muscle?
It rotates the arytenoid cartilages medially to adduct the vocal folds, closes airway to protect it (also aids with coughing)
What is the function of the transverse arytenoid?
Pulls the arytenoid cartilages together for complete adduction
What happens if lateral cricoarytenoids contract without transverse arytenoids?
The vocal cords close but not completely, leading to a whisper
What are the functions of the cricothyroid muscle?
pulls thyroid cartilage down toward cricoid cartilage to stretch and tense vocal cords, raising pitch of voice
What are the functions of the thyroarytenoid muscle?
Pulls the thyroid cartilage posteriorly toward the arytenoid cartilages to shorten and relax the vocal ligaments and folds, lowering pitch of voice
What is the function of the thyroepiglottic muscle?
Pulls the epiiglottis forward to open the larynx
What is the function of the aryepiglottic muscle?
It helps close the epiglottis
What is A?
Epiglottis
What is B?
Aryepiglottic fold
What is C?
Aryepiglottic muscle
What is D?
Oblique arytenoid muscles
What is E?
Transverse arytenoid muscle
What is F?
Posterior cricoarytenoid muscle
What is G?
Oblique part of cricothyroid muscle
What is H?
Straight part of cricothyroid muscle
What is I?
Thyrohyoid membrane
What is J?
Opening for internal laryngeal nerve
What is the function of the thyrohyoid?
Elevates the larynx with the superior hyoid muscles (helps with swallowing)
What is the function of the sternothyroid?
Pulls thyroid cartilage down towards the cricoid cartilage, helping stretch vocal cords and raise pitch of voice
What is the function of the external laryngeal nerve?
Branchiomotor to cricothyroid muscle
What is the function of the internal laryngeal nerve?
Pierces thyrohyoid membrane to provide visceral sensory and parasympathetic innervation to all of the larynx above vocal cords
What is the function of the inferior laryngeal nerve?
Visceral sensory and parasympathetic to the larynx below the vocal folds, branchiomotor to all muscles of larynx except cricothyroid
comes from the vagus nerve
What is the ramus communicans?
A communicating sensory branch from the inferior laryngeal nerve to the superior laryngeal nerve
What primordia does the mucosa of the larynx come from?
Pharyngeal arches four and six
What larynx structures come from pharyngeal arch four?
Most of epiglottis, most of thyroid cartilage
What larynx structures come from pharyngeal arch 6?
Cricoid and arytenoid
What is the only laryngeal muscle that can maximally open the airway by abducting the vocal folds?
a) thyroarytenoid
b) lateral cricoarytenoid
c) cricothyroid
d) posterior cricoarytenoid
e) transverse arytenoids
d) posterior cricoarytenoid
What laryngeal nerve is the sensory limb of the cough reflex?
a) external
b) superior
c) internal
d) recurrent
e) inferior
c) internal
Where does food often get trapped?
a) piriform recess
b) vestibule
c) valleculae
d) infraglottic cavity
e) ventricle
a) piriform recess
A deformed or undersized thyroid cartilage might be the result of deficient population of ectomesenchyme in which pharyngeal arch?
a) 1
b) 2
c) 3
d) 4
e) 6
d) 4
What are the three phases of swallowing?
Oral, pharyngeal, and esophageal phases
What occurs in the oral phase of a swallow?
Lips seal bolus in oral cavity –> tongue transports bolus to oropharynx
What occurs in the pharyngeal phase of a swallow?
Nasopharynx is sealed by soft palate contact to superior pharyngeal constrictor –> bolus propeled through the pharynx (tongue base and posteiror pharyngeal wall) while larynx is sealed off to prevent aspiration
What occurs in the esophageal phase of swallowing?
Bolus tranpsorted to cervical esophagus through upper esophageal sphincter
What nerual signals lead to an oropharyngeal swallow?
It is under control of a central pattern generator
What is the difference in nerve control between primary and secondary peristalsis?
Primary = dependent on extrinsic innervation, secondary = dependent on an intramural nerve network (myenteric plexus)
What is the most likely cause of dysphagia associated with coughing or aspiration?
Oropharyngeal
What is the most likely cause of dysphagia associated with chest pain?
Esophageal
What is the most likely cause of dysphagia associated with only solid food?
Mechanical cause (ex. stricture)
What is the most likely cause of dysphagia associated with solids and liquids?
Motor disorder
What are the two main tools to evaluate oropharyngeal dysphagia?
Viddeofluoroscopy (aka MBS), fiberoptic endoscopic evaluation of swallowing (FEES)
Dysphagia, or impaired swallowing is:
a) a symptom of larger impairment
b) unique to only older adults
c) limited inetiology, usually only to those with neurological impairment
d) synonymous with aspiration
a) a symptom of larger impairment
When discussing invasion of food or liquid into the airway, _______ is defined as ingested material below the level of the true vocal cords, whereas ______ is defined as ingested material above the level of true vocal cords.
a) penetration; aspiration
b) aspiration; penetration
c) aspiration; dysphagia
d) aspiration; superficial aspiration
b) aspiration; penetration
A 64 y.o. man with a history of DLBCL diagnosed 2 years ago presents with weight loss, hypernasality, fluxuating voice changes, low-grade fever. Imaging is remarkable for new cranial nerve lesions impacting CN X, XII. Chest x-ray on admission is notable for bilateral lower lobe infiltrates. Patient denies difficulty swallowing. What is notable about this patient’s history and complaints that would be concerning for possible dysphagia?
- involvement of CN X and XII may interfere with oral and pharyngeal phases of sawllowing
- fever and bilateral lower lobe infiltrates
- weight loss could be secondary to swallowing impairment
