Larynx

• What are the three main functions of the larynx?

  • Ventilation (fully open)
  • Sphincter (fully closed)
  • Phonation (half open/closed)
• What happens to the larynx during swallowing?

  The larynx elevates towards the soft palate
• What closes off the laryngeal inlet during swallowing?

  The epiglottis
• What are the two groups of extrinsic muscles of the larynx?

  • Suprahyoid muscles (elevate hyoid & larynx)
  • Infrahyoid muscles (depress hyoid & larynx)
• What type of cartilage is the epiglottis?

  Elastic cartilage
• What is the primary function of the cricothyroid joint?

  Alters cord length through rotation and gliding
• What is the role of the posterior cricoarytenoid muscle?

  It abducts the vocal ligaments and opens the glottis
• Which muscle is the only abductor of the vocal ligaments?

  Posterior cricoarytenoid
• What are the movements of the vocal folds during phonation?

  • Vocal folds approximate and vibrate
  • Air passes between them
  • Creates sound
• What is the effect of the cricothyroid muscle's contraction on sound?

  Increases pitch by elongating vocal ligaments
• What is the primary function of the interarytenoid muscles?

  Adduction of vocal ligaments
• What are the mechanisms involved in the sphincteric function of the larynx?

  • Elevation of the larynx
  • Lowering of the epiglottis
  • Closure of the laryngeal inlet
  • Adduction of vocal folds
  • Brief suspension of ventilation
• What triggers the cough reflex?

  Detection of a foreign body
• What are the roles of the recurrent laryngeal nerve?

  • Motor to all intrinsic muscles except cricothyroid
  • Sensory below vocal folds
• What is the venous drainage of the larynx?

  To internal jugular vein or left brachiocephalic vein
• What are the symptoms of laryngeal dysfunction caused by nerve damage?

  • Voice changes (hoarseness)
  • Airway problems (shortness of breath)
  • Swallowing problems (choking)
• What is the treatment for adductive spasmodic dysphonia?

  Injection of botulinum toxin into the muscle
• What is the phonatory cycle and its frequency range?

  • Occurs during expiration
  • Vocal folds adducted then abducted
  • Frequency range: 150-250 Hz
• How does the larynx contribute to phonation?

  It modulates pitch and sound through vocal fold movement
• What is the role of the thyroarytenoid muscle during phonation?

  Shortens and thickens vocal cords, lowering pitch
• What is the primary function of the lateral cricoarytenoid muscle?

  Narrowing the glottis for quiet respiration
• What happens to the vocal folds during forced inspiration?

  They are widely separated
• What is the innervation of the cricothyroid muscle?

  External laryngeal nerve
• What is the significance of the mucosal wave in laryngeal examination?

  Indicates frequency, amplitude, and symmetry
• How does the larynx function as a sphincter during swallowing?

  It closes to prevent food entering the airway
• What is the role of the aryepiglottic muscle during swallowing?

  Elevates the larynx and pushes epiglottis down
• What is the primary function of the thyrohyoid muscle?

  Depresses the hyoid and elevates the larynx
• What is the effect of vocal fold adduction during phonation?

  It allows sound production through vibration
• How does the larynx assist in preventing aspiration during swallowing?

  By closing the laryngeal inlet and adducting vocal folds
• What is the consequence of paralysis of the posterior cricoarytenoid muscle?

  Flaccid closure of the glottis, leading to suffocation
• What is the innervation of the interarytenoid muscles?

  Recurrent laryngeal nerve
• What is the primary function of the vocalis muscle?

  Fine adjustments to tension in vocal ligaments
• How does the laryngeal structure contribute to voice modulation?

  By altering tension and length of vocal folds
• What is the role of the thyroarytenoid muscle in sound production?

  Shortens and thickens vocal cords
• What is the significance of the arytenoid cartilages in vocal fold movement?

  They cause vocal ligaments to be abducted or adducted
• How does the larynx function during quiet respiration?

  Vocal cords are in a gap position
• What is the primary function of the vestibular folds?

  Protect the airway during swallowing
• What is the role of the cricothyroid muscle in pitch modulation?

  Increases pitch by elongating vocal ligaments
• How does the larynx assist in the cough reflex?

  Closes vocal folds to build pressure for expulsion
• What is the primary function of the aryepiglottic fold?

  Helps close the laryngeal inlet