Phrenic C4 Dominant — FRCA Primary MCQ

Instant feedback + full explanation. One question, done properly.

EasyAnatomyPhrenic C4 DominantFRCA Primary

The phrenic nerve arises from C3 C4 C5. Which root is the dominant contribution?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — C4

C4 is the dominant contribution to the phrenic nerve (C3 C4 C5 keeps the diaphragm alive). It is the sole motor supply to the diaphragm and passes over the anterior surface of scalenus anterior in the neck.

Reference: RCoA 2021 Primary FRCA Curriculum