Anatomy All of the following are true about Scalenus anterior muscle: A It is attached to the tubercle of second Rib B It is anterior to the transverse cervical aery. C It is pierced by the phrenic nerve. D It separates the subclan vein from the subclan aery 💡 Explanation All of the following are true about Scalenus anterior muscle: ✓ Correct Answer: D. It separates the subclan vein from the subclan aery