Phrenic Nerve

00:01 Couple of other important things. The phrenic nerve is quite important.

00:07 They can ask you coarse, relations, root value. Root value of phrenic is C3, C4, C5. Similar to the brachial plexus I said, it comes out laterally, then where does it go? In terms of relations. Any ideas in terms of relation to scalene muscle, in relation to the artery? Anterior to the scalene muscle.

00:35 It’s anterior to the scalene muscle, so this is one question they ask, anterior to the scalene and it’s anterior to subclavian artery. It’s anterior to the subclavian but posterior to the subclavian vein. So in the neck, the phrenic nerve, just remember this way: phrenic is quite lateral and vagus is very medial, vagus is towards the midline.

00:58 Vagus is very much close to midline. Phrenic is quite lateral, so phrenic is overlying the scalenius anterior muscle. That’s the scalene, that's scalenius anterior.

01:14 So this is your scalene, that’s the subclavian artery, so subclavian, that’s your right side, you’re looking from there, scalenius anterior, scalenius medius, subclavian artery. And your subclavian vein is in front of artery. And phrenic nerve is lying here or in front of the subclavian artery, in front of the scalenus anterior. Then the phrenic nerve comes, arches over, it lies on the heart. Then you have the right phrenic and the left phrenic. Right phrenic accompanies which structure? Inferior vena cava. Inferior vena cava. The right phrenic accompanies inferior vena cava, pierces the diaphragm at the level of T8.

02:07 That is your inferior vena cava and the right phrenic. The left phrenic nerve has got its own hiatus in the diaphragm, so it’s got its own hiatus and supplies the diaphragm.

02:20 So that’s all you need to remember about phrenic. So, you know the questions we have seen are always rehashed: root values asked, what’s the relation to the subclavian artery, what’s the relation to the scalene muscle and how does the right and the left go.

02:33 This is what they can ask you. Vagus? The hiatus of the vena cava T10? Not T8? No no, vena cava is T8, esophagus is T10 and aorta is T12.

02:50 Vagus. Vagus is the 10th cranial nerve, comes out through the jugular foramen, lies within the carotid