Larynx Flashcards
Function of the larynx
Airway protection, cough reflex, sounds production
What bone is the larynx suspended from
Hyoid
When does the larynx end
At lower border of cricoid cartilage then it’s the trachea
What are the 3 cartilages
Thyroid, arytenoid, cricoid
What are the membranes
Thyrohyoid, cricothyroid, cricotracheal
What forms margins of inlet
Epiglottis and Aryepiglottic folds.
What makes up the false cords
Free lower border of the Quadrangular membrane
What makes up the true cords
Free upper border of cricothyroid membrane
What makes up the supraglottis
Inlet to false cords
What makes up the glottis
True cords + 1 cm
What makes up the subglottis
To end of cricoid cartilage
What is the purpose of the saccule between cords
Mucous glands to keep voice folds moist- strat squamous
What is a vallecula
Notch to put the scope when intubating
What are the purpose of the larynx muscles
Alter size and shape of inlet, and tension and position of cords.
What muscles abducts the vocal cords
Posterior cricoarytenoid
What nerve supplies most of the muscles
Recurrent laryngeal nerve of CN X
What does the external branch of superior laryngeal nerve supply
Cricothyroid muscles motor
What does the internal branch of superior laryngeal nerve supply
Sensory to supraglottis
What does the recurrent laryngeal nerve supply
Intrinsic muscles except cricothyroid and sensory to sub and glottis
What is the path of the left RLN
under aorta the ascends in tracheoesophageal groove close to thyroid and inferior thyroid arteries
What position are the vocal cords when swallowing
Adducted
What happens to larynx during swallowing
Hyoid bone elevates and moves anteriorly by contraction of suprahyoid muscles
This causes larynx to move up and forwards and tongue pushes epiglottis horizontally.
What happens to vocal cords when talking
Partially open but mostly adducted and air forced through to create vibration
What position of the vocal cords produces high pitch
Taut
What does contraction of cricothyroid muscle do
Tilts thyroid cartilage forwards on cricoid to increase vocal cord tension
What happens to vocal cords in coughing
Adducted to build intrathoracic pressure the abducted to produce explosive outflow of air
Complication of thyroid surgery
External branch of superior laryngeal nerve sits close to superior thyroid artery. Cricothyroid not innervated
Hoarseness at high pitch
What happens in vocal cord in vocal cord palsies
RLN damaged from surgery, aneurysm, cancer, disease
Unilateral- hoarseness as stuck in paramedian position
Bilateral = narrow glottis = emergency
What happens in laryngitis
Inflammation
Hoarse/ weak voice
URTI hx
Self limiting
What causes nodules
Acute trauma, chronic irritation, hoarseness for 3 weeks
What is a common cause of epiglottitis
Haemophilus influenzae
What does epiglottitis present like
Sniffing position Still 2-6 years Not vaccinated Quick deterioration
How to treat epiglottitis
Secure airway and antibiotics
Presentation of Croup
Viral
6month to 3 years
Barking cough
Adrenaline nebs and steroids if bad
What is an example of a definitive airway
ETT
Secure and protects lower respiratory tract
