Larynx Flashcards
What is the larynx?
Tube created by ligaments, membranes, cartilage and muscles
What bone does the larynx lie below?
Hyoid bone
What is the functions of the larynx?
Transmits air into and out of the lower respiratory tract and speech and also protect airway from food
Where does the larynx begin and end?
Laryngeal inlet to the trachea
What are the three single cartilages in the larynx?
thyroid, cricoid and epiglottis
What is the most important of the three paired cartilages?
Arytenoid
What is important about the cricothyroid cartilage?
Gives emergency access to provide patent airway- cut with scalpel
Where is the thyroid in relation to the larynx?
Anterior to the laryngopharynx
What is the larynx lined with?
Mucous membrane
What are the three regions of the larynx due to mucous membrane?
Supraglottis (above true vocal cords) Glottis (At the true vocal cords) Infraglottis (below the vocal cords)
What kind of epithelium is in the larynx?
Pseudostratified ciliated epithelium (except for vocal cords- stratified squamous)
What is the innervation of most larynx muscles?
Recurrent laryngeal nerves
What does the internal branch of the superior laryngeal nerve innervate?
Sensory to supraglottic muscles
What does the external branch of the superior laryngeal nerve innervate?
Motor to cricothyroid
What would you see through a laryngoscope?
Epiglottis- point of rima glottidis is forward
What would you see through a nasoendoscopy?
Rima glottis is posterior
What is the larynx function when moving the vocal cords?
Move positions and alter tensions in vocal cords Posterior circoarytendoid muscle opens vocal cords- abducts- only muscle that does this During inspiration and expiration- vocal cords abduct and open During phonation (speech)- vocal cords abduct and close- expired air forced through to vibrate a column of air High pitched if taut Low pitched if relaxed Length and tension increased by contraction of Cricothyroid muscle (innervated by external superior laryngeal nerve Tilts the thyroid cartilage forward on cricoid increasing tension of vocal cords- high pitched so injury to nerve causes hoarseness of voice During coughing- vocally cords powerfully adduct, intrathoracic pressure builds, then the cords suddenly opens and abducts
What is the larynx function when swallowing?
Close the larynx during swallowing, protecting the respiratory tract Muscles contract and narrow laryngeal inlet and pull down epiglottis Elevation of the larynx assists this Closure of vocal cords
What does the larynx do when breathing?
Open the larynx and allow movement of air during inspiration and expiration
What happens in vocal cord palsies?
Closely associated with inferior thyroid artery so could be injured in thyroid surgery Aortic aneurysm, cancer involving apex of lung, disease or surgery involving larynx Supplies intrinsic muscles of the larynx responsible for vocal cord movement Unilateral- lead to hoarseness of voice and ineffective cough Paralysed will assume a paramedian position Between abducted and adducted Still can breath and may compensate over time Bilateral- Narrow glottis, significant airway obstruction so emergency surgical airway Both vocal cords paralysed and paramedian
What are some other conditions of the vocal cord?
laryngitis, laryngeal nodules, laryngeal cancerCroup, epiglottis, laryngeal oedema- swelling of larynx can threaten the airway and will present with striador, raised respiratory rate, distress, hypoxia and maybe cyanosis
Organisation of the cervical plexus?
Describe the anatomy of the thyroid gland, its anatomical relations in the neck and the relationship between its blood supply and the nerves supplying the larynx and vocal cords?
