Pharynx & larynx

Question 1

Piriform fossa: clinical significance

Answer 1

• I: Internal Laryngeal n.
• fish bones (and other items) get stuck here

Question 2

List general attachments, innervation, & Fx of muscles of pharynx

Answer 2

• S. Constrictor
  
  • Attach: Pterygomandibular raphe
• Middle Constrictor
  
  • Attach: Hyoid & cartilage
• I. Constrictor
  
  • Attach: Thyroid & Cricoid cartilage
• All constrictors attach @ Pharyngeal Raphe post.
• All constrictors innervated by CN X

Question 3

Tonsillar ring of Waldeyer clinical significance

Answer 3

• Laryngoscope curves on tube pull tongue & epiglottis forward facilitating insertion
• ring includes:
  
  • palatine tonsil
  • lingual tonsil
  • valleculae spaces b/w tongue and epiglottis

Question 4

Pharynx: Arterial supply & lymphatic drainage

Answer 4

Arterial supply

• ECA: tonsillar br. of ascending pharyngeal a.
• Facial a.: tonsillar br. & ascending palatine a.
• Subclavian a.: thyrocervical trunk br. eg pharyngeal branches from inferior thyroid a.

Lymphatic drainage:

• Deep cervical lymph nodes including:
  
  • Retropharyngeal nodes
  • Infrahyoid
  • Paratracheal
• Jugulodigastric
• Internal jugular
• Palatine tonsils: thru the pharyngeal wall into the jugulodigastric nodes

Question 5

Contributions of the phayngeal nerve plexus

Answer 5

• Upper anterior part of nasopharynx:
  
  • pharyngeal br. of CN V2 (remainder by CN IX)
• Oropharynx (plus lower post. nasopharynx & upper part of laryngopharynx): CN IX via pharyngeal plexus
• Laryngopharynx (lower part): CN X via pharyngeal plexus
  
  • including all constrictors
  • all pharynx muscles except Stylopharngeus (CN IX)

Question 6

Muscles of larynx attachments, innervation & fx

Answer 6

• Post. arytenoid muscles:
  
  • Action: AB-duct vocal folds (only abductor)
• Cricothyroid:
  
  • Action: raise pitch, increase tension on vocal ligaments
  • I: Internal Laryngeal n.
• Lateral Cricoarytenoid:
  
  • Action: AD-duct, phonation
• All Laryngeal muscles innervated by RLN except Cricothyroid
• S. Laryngeal n give rise to:
  
  • Internal: supplies mucus membrane in supraglottic compartment; injury results in lost of cough reflex
  • External: supplies Cricothyroid; injury results in lost of pitch & monotone voice

Arterial, venous & lymphatic drainage

• Arterial: S. & I. thyroid a. & S. & I. laryngeal a.
• Venous: S. & I. laryngeal v.
• Lymph: Pretracheal & Deep Cervical lymph nodes