W1: S7 - The Hyoid Bone, Strap Muscles of the Neck and Cervical Plexus

Question 1

Identify the parts of the hyoid bone

Answer 1

• A. Middle pharyngeal constrictor muscle origin
• C. Hyoglossus muscle origin
• D. Greater Horn
• E. Lesser Horn
• F. Body of hyoid
• G. Stylohyoid ligament.

Question 2

What are the muscles/sets of muscles that attach to the hyoid bone?

Answer 2

1. Suprahyoid muscles
2. Infrahyoid muscles
3. Hypoglossal muscle and genioglossus (muscle of tongue)
4. Middle pharyngeal contracter (muscle of pharynx)

Question 3

What are the 4 suprahyoid muscles? (MA DAD SELLS GAVISCON)

Answer 3

• Myolohyoid
• Digastric
• Stylohyoid
• Geniohyoid

Question 4

What is the nerve supply of the myolohyoid muscle?

Answer 4

Myolohyoid nerve (V₃)

Question 5

What is the nerve supply of the geniohyoid muscle?

Answer 5

Hypoglossal nerve (C1)

Question 6

What two nerves supply the digastric muscles?

Answer 6

1. Myolohyoid nerve (trigeminal) [anterior belly]
2. Facial nerve [posterior belly]

Question 7

What nerve supplies the stylohyoid?

Answer 7

Facial nerve

Question 8

Question 9

What is the action of the suprahyoid muscles on the mandible and hyoid bone?

Answer 9

Depression of the mandible and elevation of the hyoid bone

Question 10

What are the 4 infrahyoid muscles? TOSS

Answer 10

• T - Thyrohyoid
• O - Omohyoid
• S - Sternohyoid
• S - Sternothyroid

Question 11

What is the nerve supply of the thyrohyoid?

Answer 11

C1 via the hypoglossal nerve

Question 12

What is the nerve supply of the omohyoid?

Answer 12

C2, C3

Question 13

What is the nerve supply of the sternothyroid and sternohyoid muscles?

Answer 13

C2, C3

Question 14

What is C2, C3 better known as?

Answer 14

Ansa Cervalis

• Loop of nerves that are part of cervical plexus lying superficial to IJV
• Innervate infrahyoid muscles except thyroid which is innvervated by C2 via hypoglossal

Question 15

What action do the infrahyoid muscles have on the hyoid bone?

Answer 15

• Depression
• Stabilisation
  
  • during swallowing

Question 16

What are the vertebral root values of the cervical plexus?

Answer 16

C1 - C5

Question 17

Between which two muscles does the cervical plexus emerge?

Answer 17

“The cervical plexus is formed in the neck, and lies deep to the sternocleidomastoid muscle, and anterolateral to the levator scapulae and middle scalene muscles.”

Question 18

What nerve arises from the cervical plexus and travels through the thorax?

Answer 18

• Phrenic nerve
  
  • Also has afferent fibres from pericardium