Pharynx and Larynx

Question 1

describe the innervation to the 3 regions of the pharynx

Answer 1

1. nasopharynx = pharyngeal branch of maxillary nerve (V2)
   
   • pharyngeal tonsil (adenoids)
   • pharyngotympanic tube
2. oropharynx = glossopharyngeal n. (IX) via pharyngeal plexus
   
   • palatine tonsils
   • valleculae
3. laryngopharynx = vagus nerve via the internal branch of the sup. laryngeal nerve
   
   • piriform recess (fossa)

Question 2

describe the innervation and function of the muscles of the pharynx

Answer 2

• circular muscles (constrictors) = CN X
  
  • as a group constrict the lumen of the pharynx propelling bolus downward during swallowing
  • superior, middle and inferior constrictors

Question 3

describe the longitudinal muscles of the pharynx

Answer 3

• salpingopharyngeus
  
  • elevates the pharynx, pulls auditory tube to equalize pressure in middle ear (pharyngeal branch of CN X)
• palatopharyngeus
  
  • elevates pharynx/larynx (pharyngeal branch of CN X)
• stylopharyngeus
  
  • elevates pharynx/larynx during swallowing (CN IX)

Question 4

describe the gag reflex

Answer 4

• afferent limb (sensation from the pharynx): CN IX
• efferent limb (motor response of the pharynx): CN X

Question 5

describe the muscle innervation of the tongue, palate, pharynx and larynx and their exceptions

Answer 5

Question 6

describe the blood supply of the pharynx

Answer 6

• external carotid artery
  
  • ascending pharyngeal a.
  • ascending palatine and tonsillar branches of fascial a.
  • numerous smaller branches of maxillary and lingual a.
• subclavian artery
  
  • pharyngeal branch of inf. thyroid a.

Question 7

describe the venous drainage of the pharynx

Answer 7

• venous drainage from the pharynx
  
  • pterygoid plexus of infratemporal fossa -> facial/retromandibular veins -> IJV

Question 8

describe the lymphatic drainage of the pharynx

Answer 8

to deep cervical nodes (via retropharyngeal, paratracheal and infrahyoid nodes)

Question 9

what structure is at risk of injury in the piriform recess?

Answer 9

internal laryngeal nerve

Question 10

contrast the lymph drainage above vocal cords vs below vocal cords

Answer 10

• above vocal cords: to deep cervical nodes along IJV
• below vocal cords: to deep nodes associated with inf. thyroid a. or trachea