Larynx Flashcards
Describe the nerve supply of the larynx?
Nerve supply to larynx divided into superior and recurrent laryngeal nerve
Superior laryngeal divided into internal and external:
-Internal: Sensory mucosa above vocal cords
-External: cricothyroid muscle which is adductor and tensor of the cords
Recurrent laryngeal:
-sensory to mucosa below the cords
-all intrinsic muscles except cricothyroid
Which vertebral level corresponds to the position of the larynx?
-C3-C6 vertebral level
What are the cartilages of the larynx?
3 paired and 3 unpaired
Unpaired:
Superior to inferior:
–> Epiglottis
–> Thyroid
–> Cricoid
Paired:
-Arytenoid x2
-Corniculate x2
-Cuneiform x2
What is the blood supply to the larynx?
laryngeal branches of superior and inferior thyroid arteries
Name the intrinsic and extrinsic membranes of the larynx
The extrinsic membranes connect the laryngeal cartilage to surrounding structures for support (hyoid bone and trachea)
–> Thyrohyoid membrane
–> Hyoepiglottic ligament
–> Cricotracheal membrane
Intrinsic: hold cartilages of larynx together as one functional unit
-Cricothyroid ligament
-Quadrangular membrane
-Thryoepiglottic ligament
Name the extrinsic muscles of the larynx and their function?
Suprahyoid (elevates larynx)
-Digastric
-Stylohyoid
-Mylohyoid
-Geniohyoid
Infrahyoid (depresses larynx)
-Omohyoid
-Sternohyoid
-Sternothyroid
-Thyrohyoid
Name the intrinsic muscles of the larynx
- Abductors/adductors:
–> Adductor: lateral cricoarytenoid muscle (main), transverse arytenoids muscles
–> abductor: posterior cricoarytenoid muscles-only muscle able to open the vocal cords - Sphincters (Muscles to close laryngeal inlet during swallowing)
-Lateral cricoarytenoid
-Transverse arytenoids
-Oblique arytenoids - Tensors (muscles to raise pitch of voice)
-Cricothyroid - Relaxers (muscles altering pitch of voice)
-Thyroarytenoid
-Vocalis
What is the funciton of the intrinsic muscles of the larynx?
Move and alter length and tension of vocal cords, and size and shape of rima glottidis
Name the subdivisions of the laryngeal cavity
- Vestible
- Middle (ventricle/laryngeal sinus)
- infraglottic space
Name some causes of vocal cord palsy
- Malignancy (30%): bronchus, oesohpagus, thyroid, nasopharynx
- Iatrogenic (25%): thyroid, parathyroid, oesophageal, pharyngeal pouch, left lung surgery
- External trauma (15%)
- Idiopathic (15%)
- Others (15%): neurological disorders, myopathies
What are the different types of vocal cord palsies?
-Unilateral or bilateral
-Temporary or permanent
What is the clinical significance of a bilateral vocal cord palsy?
Bilateral vocal cord palsies present with stridor
What forms the superior laryngeal aperture?
-Anterior: epiglottis
-Posterior: arytenoid cartilages
-Lateral: aryepiglottic fold
Label this external anterior view of the larynx
Label this saggital view of the larynx
Label this endoscopic view of the larynx
Label the laryngeal cartilages
Arytenoid cartilages can move laterally and medially, and about a vertical axis. When muscular process moves backwards and forwards, the vocal process is abducted and adducted
Arytenoid cartilages can move laterally and medially, and about a vertical axis. When muscular process moves backwards and forwards, the vocal process is abducted and adducted
Vocal ligaments run from thyroid cartilage to the tips of the vocal processes of the arytenoid cartilages. Between them is the vocal opening, or rima glottidis. Tension is affected by the tilt of the cricoid cartilage. Gap between them (rima glottidis) is affected by the rotation of the arytenoid cartilage
Vocal opening shape:
Diamond shaped in quite breathing
Widens to triangle in deep breathing
Narrows to slit during speech
What is the action of the cricothyroid muscle?
-The cricothyroid muscle pulls the arch of the cricoid cartilage upwards.
- In doing so, it pulls the arytenoid cartilages backwards, making the vocal folds longer and tighter.
Extrinsic muscles of larynx
Extrnisic muscles of larynx
membranes of the larynx
membranes of the larynx
