Which statement best describes the relationship between conduction velocity and repolarization for the fast vs slow pathways?

Which statement best describes the relationship between conduction velocity and repolarization for the fast vs slow pathways?

• A. The fast pathway conducts quickly and repolarizes slowly; the slow pathway conducts slowly and repolarizes quickly
• B. The fast pathway conducts slowly and repolarizes quickly; the slow pathway conducts quickly and repolarizes slowly
• C. Both conduct at the same speed and repolarize similarly
• D. The slow pathway conducts quickly and repolarizes slowly

Answer: (A)

Conduction velocity and the recovery process of a pathway are inversely related: tissues that conduct impulses quickly tend to have longer recovery times, while those that conduct slowly recover sooner. The fast pathway depolarizes and conducts rapidly, but its recovery (repolarization) is relatively slow, meaning it remains refractory for a longer period. The slow pathway, on the other hand, conducts impulses more slowly and its recovery is quicker, so repolarization happens sooner. So the best description is that the fast pathway conducts quickly and repolarizes slowly, while the slow pathway conducts slowly and repolarizes quickly.

Conduction velocity and the recovery process of a pathway are inversely related: tissues that conduct impulses quickly tend to have longer recovery times, while those that conduct slowly recover sooner.

The fast pathway depolarizes and conducts rapidly, but its recovery (repolarization) is relatively slow, meaning it remains refractory for a longer period. The slow pathway, on the other hand, conducts impulses more slowly and its recovery is quicker, so repolarization happens sooner.

So the best description is that the fast pathway conducts quickly and repolarizes slowly, while the slow pathway conducts slowly and repolarizes quickly.