Why does conduction velocity slow down at the AV node?

Why does conduction velocity slow down at the AV node?

• A. To minimize heart rhythm
• B. To allow for ventricles to fill with blood
• C. To delay electrical signals
• D. To increase heart rate

Answer: (B)

The conduction velocity slows down at the AV node primarily to allow for ventricles to fill with blood. This delay is crucial for proper cardiac function. After the atria contract and pump blood into the ventricles, the AV node provides a necessary pause before the electrical signal continues to the ventricles. This allows the ventricles to receive the full volume of blood from the atria before they contract. If the conduction through the AV node were too rapid, the ventricles would not have sufficient time to fill, which could lead to decreased cardiac output and ineffective pumping of blood throughout the body. Therefore, this strategic slowdown at the AV node is critical for ensuring that the heart maintains an efficient rhythm and optimizes blood circulation.