15.2 Root of the Neck

Question 1

Identify the anterior, middle, and posterior scalene muscles. What are their function and innervation?

Answer 1

• Fxn: Anterior functions to flex head bi-laterally, and all three do lateral flexion uni-laterally. Also important as secondary muscles of respiration by elevating the ribs during forced expiration.
• Innervation from anterior rami of C2-C8.

Question 2

Identify the phrenic nerve passing down on the surface of the anterior scalene. Spinal roots?

Answer 2

C3-5

Question 3

Identify the right and left subclavian veins as well as the right and left internal and external jugular veins.

Answer 3

-

Question 4

Locate and describe the thoracic duct as well as the right lymphatic duct.

Answer 4

• Thoracic duct (left side): drains into junction of internal jugular and subclavian veins on left.
• Right lymphatic duct: drains into junction of internal jugular and subclavian veins on the right.

Question 5

Locate the left and right recurrent laryngeal nerves.

Describe their course and important areas of innervation.

Answer 5

• The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right subclavian artery then traveling upwards.
• Innervation: Branches off vagus. Provide Sensory below the false vocal folds and all the other muscles of the larynx

Question 6

Identify the sympathetic trunk as well as the middle cervical ganglion and inferior cervical/stellate ganglion (if possible).
Describe the overall general purpose of these ganglion.

Answer 6

Provide sympathetic regions to the head and neck. (as well as other parts of the body). (figure 71.2)

Question 7

Identify the subclavian artery as well as its following branches:

1. Internal thoracic artery
2. Vertebral artery
3. Thyrocervical trunk
   a. Inferior thyroid artery
   - Ascending cervical artery
   b. Suprascapular artery
   c. Transverse cervical arteries

Answer 7

• the internal thoracic artery passing inferiorly
• the vertebral artery, a superiorly directed, deeply positioned branch
• the thyrocervical trunk, which terminates by dividing into the inferior thyroid, the suprascapular, and the transverse cervical arteries
• the ascending cervical artery, a branch of the inferior thyroid artery

Question 8

Identify the costocervical trunk as well as its branches:
-Deep cervical artery
-Supreme thoracic artery
What is the source for this trunk?

Answer 8

Subclavian a.