The cardiac center coordinates autonomic input to the heart; which two divisions provide this input?

The cardiac center coordinates autonomic input to the heart; which two divisions provide this input?

• A. Sympathetic and parasympathetic.
• B. Somatic and autonomic.
• C. Central and peripheral.
• D. Endocrine and nervous.

Answer: (A)

The heart’s rate and rhythm are controlled by the autonomic nervous system, which has two opposing pathways that innervate the heart. The sympathetic division speeds up heart rate and strengthens contraction by releasing norepinephrine onto beta-1 receptors in the heart, helping to meet higher metabolic demands. The parasympathetic division slows heart rate and reduces conduction through the SA and AV nodes by releasing acetylcholine onto muscarinic receptors, mainly via the vagus nerve. The cardiac center in the brainstem coordinates these inputs to fine-tune cardiac activity. Other options don’t fit because they describe different nervous system divisions or signaling systems, not the two branches of autonomic input to the heart.

The heart’s rate and rhythm are controlled by the autonomic nervous system, which has two opposing pathways that innervate the heart. The sympathetic division speeds up heart rate and strengthens contraction by releasing norepinephrine onto beta-1 receptors in the heart, helping to meet higher metabolic demands. The parasympathetic division slows heart rate and reduces conduction through the SA and AV nodes by releasing acetylcholine onto muscarinic receptors, mainly via the vagus nerve. The cardiac center in the brainstem coordinates these inputs to fine-tune cardiac activity. Other options don’t fit because they describe different nervous system divisions or signaling systems, not the two branches of autonomic input to the heart.