Extrinsic Laryngeal and Supplementary Neck Muscles

Question 1

Extrinsic Laryngeal Muscles

Answer 1

• Sternothyroid
• Thyrohyoid

Question 2

Sternothyroid Muscle (function and attachment)

Answer 2

• Origin: Manubrium of sternum
• Insertion: Thyroid cartilage
• Function: Depresses the larynx
• Innervation: Cervical nerves 1-3

Question 3

Thyrohyoid Muscle (function and attachment)

Answer 3

• Origin: Thyroid cartilage
• Insertion: Hyoid bone
• Functions: Depresses hyoid bone + Elevates the larynx
• Innervation: Cervical nerve 1

Question 4

Suprahyoid Muscles (function and attachment)

Answer 4

Digastric (Anterior + Posterior), Stylohyoid, Mylohyoid, Geniohyoid

• Support the hyoid bone from above
• Known as laryngeal elevators
• Move the hyoid upwards and forwards or backwards.
• Therefore move the larynx in the same direction
• Important in swallowing

Question 5

Anterior Belly of Digastric (function and attachment)

Answer 5

• Origin: Mandible (jaw bone)
• Insertion: Intermediate tendon on hyoid bone
• Function: Moves hyoid and larynx upwards and forwards
• Innervation: CN V (Trigeminal)

Question 6

Posterior Belly of Digastric (function and attachment)

Answer 6

• Origin: Mastoid process on temporal bone
• Insertion: Intermediate tendon on hyoid bone
• Function: Moves hyoid and larynx upwards and backwards
• Innervation: CN VII (Facial Nerve)

Question 7

Stylohyoid Muscle (function and attachment)

Answer 7

• Origin: Styloid Process of temporal bone
• Insertion: Body of hyoid bone
• Function: Moves hyoid and larynx upwards and backwards
• Innervation: CN VII (Facial)

Question 8

Mylohyoid Muscle (function and attachment)

Answer 8

• A thin sheet of muscle which forms the floor of the mouth
• Origin: Inside edges of the mandible
• Insertion: Midline raphe (tendon running down center of floor of mouth) and hyoid bone
• Function: Moves hyoid and larynx upwards and forwards
• Innervation: CN V (Trigeminal)

Question 9

Geniohyoid Muscle (function and attachment)

Answer 9

• Locatd superior to mylohyoid (closer to tongue)
• Origin: Center of mandible
• Insertion: Hyoid bone
• Function: Moves hyoid and larynx upwards and forwards
• Innervation: Cervical nerve 1

Question 10

Infrahyoid Muscles (function and attachment)

Answer 10

Sternohyoid, Omohyoid

Laryngeal Depressors (support the hyoid and larynx from below)

Question 11

Sternohyoid Muscle (function and attachment)

Answer 11

• Origin: Manubrium of sternum and medial part of clavicle
• 􏰁Insertion: Hyoid bone
• 􏰁Functions: Moves hyoid and larynx
• 􏰁Innervation: Cervical nerves 1-3

Question 12

Omohyoid Muscle (function and attachment)

Answer 12

• Shoulder-to-hyoid bone muscle on the front and side of the neck
• Anterior Belly:
  
  • 􏰁Origin: Intermediate tendon (connects to clavicle)
  • 􏰁Insertion: Hyoid bone 􏰁
• Posterior Belly:
  
  • 􏰁Origin: Scapula
  • 􏰁Insertion: Intermediate tendon
• Function: Moves hyoid and larynx downwards and backwards
• Innervation: Cervical nerves 1