Larynx & Neck

• 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?

  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 made of?

  Elastic cartilage
• What are the main laryngeal cartilages?

  • Thyroid cartilage
  • Cricoid cartilage
  • Arytenoid cartilage
  • Epiglottis
  • Hyoid
• What is the function of the cricothyroid joint?

  Alters cord length through rotation and gliding
• What movements are associated with the cricoarytenoid joint?

  Rocking and sliding of vocal folds
• What are the laryngeal membranes and spaces?

  • Vestibular fold (false vocal cord)
  • Vocal fold (true vocal cord)
  • Epiglottis
  • Aryepiglottic fold
  • Ventricles
  • Rima glottidis
• What is the role of the posterior cricoarytenoid muscle?

  It abducts the vocal ligaments
• What happens during phonation?

  Vocal cords vibrate as air passes between them
• What is the effect of the thyroarytenoid muscle on vocal cords?

  It shortens and thickens the vocal cords
• What does the cricothyroid muscle do to the vocal ligament?

  It increases tension and length of the vocal ligament
• What is the phonatory cycle?


  • Occurs during expiration
  • Vocal folds are adducted
  • Pressure builds below vocal folds
  • Vocal folds open and close rapidly
  • Produces sound at 150-250 Hz
• What is the primary function of the recurrent laryngeal nerve?

  Motor to all intrinsic muscles except cricothyroid
• What is the role of the cough reflex?

  Dislodges foreign bodies from the airway
• 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 function of the superior laryngeal nerve?

  Sensory above vocal folds
• What is the treatment for adductive spasmodic dysphonia?

  Injection of botulinum toxin
• What are the arteries involved in laryngeal vasculature?

  • Superior thyroid artery
  • Inferior thyroid artery
  • Thyroid ima artery
• What are the veins involved in laryngeal drainage?

  • Superior thyroid vein
  • Middle thyroid vein
  • Inferior thyroid vein
• What can cause laryngeal dysfunction?

  Inadvertent injury during surgery
• How does the larynx function as a sphincter?

  It closes to prevent food entering the airway
• What are the mechanisms of the sphincteric function of the larynx?

  • Elevation beneath the tongue
  • Lowering of the epiglottis
  • Closure of the laryngeal inlet
  • Adduction of vocal folds
  • Suspension of ventilation
  • Coughing as a last resort
• Fill in the blanks

  A) epiglottis

  B) hyoid

  C) thyroid cartilage

  D) cricoid

  E) superior cornu

  F) thyrohyoid membrane

  G) cricothyroid membrane

  H) inferior cornu

  
• What are the 2 laryngeal joints?

  Criocothyroid (mainly alters cord length)

  Criocoarytenoid (mainly opens & closes folds)
• Fill in the blanks

  A) Tongue

  B) Epiglottis

  C) Aryepiglottic fold

  D) Cuneiform tubercle

  E) Corniculate tubercle

  F) Vestibular fold

  G) Vocal fold

  H) Rima glottidis

  I) Laryngeal inlet

  J) Vestibule

  K) Piriform recess

  L) Laryngopharynx

  
• Fill in the blanks

  A) Vallecula

  B) Piriform fossa

  
• What happens to the vocal & vestibular folds during respiration & phonation?


  Quiet respiration = gap between vocal cords

  Phonation = vocal cords are in close approximation to each other & vibrate as air passess between them
• Fill in the blanks

  A) vocal process

  B) Arytenoid cartilage

  C) muscular process

  
• Fill in the blanks

  A) Vocalis

  B) transverse arytenoid

  C) oblique arytenoid

  D) Posterior circo-arytenoid

  E) Lateral crico-arytenoid

  
• What is the function of posterior crico-arytenoid?

  Rotates & pulls arytenoids down laterally

  Abducts vocal ligaments

  Opens glottis (only muscle that does this)
• What is the function of the inter-arytenoids?

  Adduction of vocal ligaments (glottis narrowed)
• What is the innervation of posterior crico-arytenoid?

  Recurrent laryngeal nerve
• What is the innervation of the inter-arytenoids?

  Recurrent laryngeal nerve
• What is the function of lateral crico-arytenoid?

  Rotates arytenoids

  Brings vocal processes closer together

  Glottis is narrowed (e.g. for quiet respiration)
• What is the innervation of lateral crico-arytenoid?

  Recurrent laryngeal nerve
• Fill in the blanks

  A) aryepiglottic

  B) saccule

  C) thyro-arytenoid

  
• What is the function of thyroarytenoids?

  Shortening & thickening of vocal cords

  Decreases pitch of sound
• What is the function of vocalis?

  Fine adjustments to tension in vocal ligaments

  Changes timbre of voice