A 59 year old man complains of recurrent attacks of pain in the region of left shoulder radiating to sternum and the pit of stomach. The attacks of pain came at lengthy intervals until the last two days when it became continuous. The physician diagnosed it as angina pectoris. In this case the pain pathway from the hea is carried by:
A 59 year old man complains of recurrent attacks of pain in the region of left shoulder radiating to sternum and the pit of stomach. The attacks of pain came at lengthy intervals until the last two days when it became continuous. The physician diagnosed it as angina pectoris. In this case the pain pathway from the hea is carried by:
💡 Explanation
## **Core Concept**
The question tests the understanding of the neural pathway for cardiac pain transmission. Cardiac pain, such as that experienced in angina pectoris, is transmitted through sympathetic afferent fibers that accompany the coronary arteries and the aorta. These fibers carry the pain signals from the heart to the spinal cord.
## **Why the Correct Answer is Right**
The correct answer involves the **T2-T5 sympathetic afferent fibers** that innervate the heart. These fibers are responsible for transmitting pain signals from the heart. The pain of angina pectoris is typically referred to the dermatomes T2-T5, which include the left shoulder, arm, chest, and upper abdomen. This referral pattern occurs because the cardiac sympathetic afferent fibers enter the spinal cord at these levels, and the brain interprets the pain as coming from the dermatomes supplied by these spinal nerves.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not accurately represent the pathway for cardiac pain transmission.
- **Option B:** This option is incorrect as it does not specifically relate to the known pathway for cardiac pain.
- **Option D:** This option is incorrect because it does not accurately describe the neural pathway responsible for transmitting cardiac pain.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the pain of angina pectoris is often referred to areas outside the chest, such as the left shoulder, arm, and jaw, due to the convergence of cardiac and somatic afferent fibers onto the same spinal neurons. This phenomenon explains why cardiac pain can sometimes be mistaken for pain from other sources.