The sinoatrial node is supplied predominantly by a branch of which artery in most individuals?
- A Left anterior descending artery
- B Right coronary artery (55-60% of people) ✓
- C Left circumflex artery
- D Posterior interventricular artery
Correct answer: B. Right coronary artery (55-60% of people)
Explanation
The SA node artery branches from the right coronary artery (proximal segment, near the origin of the acute marginal branch) in approximately 55-60% of individuals, and from the left circumflex artery in the remaining 40-45%. In right-dominant circulation, the right coronary artery also supplies the AV node via the AV nodal artery. Occlusion of the proximal RCA can therefore cause both SA and AV nodal dysfunction.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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