Phrenic nerve (dave's notes)

Question 1

Where does the phrenic nerve commence? What is its initial course?

Answer 1

From C4 over anterior scalene muscle behind the subclavian vein

Question 2

What rule does the course of the phrenic nerve follow?

Answer 2

Each nerve runs as par lateral as possible, then moves anteriorly.

Question 3

What are the contacts of the right phrenic nerve?

Answer 3

Venous structures:
Right brachiocephalic vein
SVC
Right atrium
IVC (through foramen)

Question 4

What are the contacts of the left phrenic nerve?

Answer 4

Lies lateral to the left common carotid artery, subclavian artery, crosses the arch lateral to the superior intoercostal vein, over the left ventricle to the apex, then pierces the diaphragm.

Question 5

What happens to the phrenic nerve on the underside of the diaphragm?

Answer 5

Each nerve splits into anterior, lateral and posterior branches that radiate out.

Question 6

What fraction of the phrenic nerve is motor? What is the rest?

Answer 6

2/3 motor

1/3 sensory

Question 7

What is the blood supply of the phrenic nerve?

Answer 7

The pericardiophrenic artery