Physiology Starling’s law of the heart A Does not operate in the failing heart B Does not operate during exercise C Explains the increase in cardiac output that occurs when venous return is increased D Explains the increase in cardiac output when the sympathetic nerves supplying the heart stimulated 💡 Explanation Starling's law of the heart ✓ Correct Answer: C. Explains the increase in cardiac output that occurs when venous return is increased