Laryngeal Anatomy

Cartilages

• Unpaired
  • Thyroid cartilage – Level of C4~5
  • Cricoid cartilage
  • Epiglottis
• Paired
  • Arytenoid
  • Cuneiform
  • Corniculate

Muscles

• Intrinsic
  • Cricothyroid
    • Originates in cricoid cartilage and inserts into thyroid
    • Tenses vocal cords and elevates voice
  • Thyroarytenoid
    • Originates in thyroid cartilage and inserts into arytenoid cartilage
    • Relaxes vocal cords and depresses voice
  • Posterior cricoarytenoid
    • Abducts the vocal cords
  • Lateral cricoarytenoid
    • Adducts the vocal cords
  • Oblique and transverse arytenoids
    • Adducts the vocal cords
• Extrinsic
  • Strap muscles

Innervation

Sensory

• Internal branch of superior laryngeal nerve

Motor

• Cricothyroid – External branch of the superior laryngeal nerve
• All other intrinsic muscles – Recurrent laryngeal nerve

Blood supply

• Superior laryngean artery (branch of external carotid)
• Inferior laryngeal artery (branch of thyrocervical trunk from subclavian artery)

Associations

• The thyroid glands lie inferolateral to the larynx (lateral to the cricoid, the isthmus is inferior to the cricoid)
• The oesophagus, anterior longitudinal ligament, cervical vertebrae lies posterior to the larynx
• The brachiocephalic trunk may arch superiorly close to the cricothyroid membrane in an anatomical variant

Sakurai 2016

Answer by Sakurai