Compared with the fast pathway, the slow pathway conducts impulses at what rate?

Compared with the fast pathway, the slow pathway conducts impulses at what rate?

• A. Slower
• B. Faster
• C. The same
• D. Variable

Answer: (A)

In the AV node there are two parallel pathways with different conduction properties. The fast pathway carries impulses quickly through a larger, more efficiently coupled tract, while the slow pathway conducts more slowly because its tissue has higher resistance and relies on slower calcium-mediated conduction. So, compared with the fast pathway, the slow pathway conducts impulses at a slower rate. This slower conduction is what allows potential reentrant circuits to form under certain conditions, such as AV nodal reentrant tachycardia, where the impulse can travel down the slow pathway and return up the fast pathway.

In the AV node there are two parallel pathways with different conduction properties. The fast pathway carries impulses quickly through a larger, more efficiently coupled tract, while the slow pathway conducts more slowly because its tissue has higher resistance and relies on slower calcium-mediated conduction.

So, compared with the fast pathway, the slow pathway conducts impulses at a slower rate. This slower conduction is what allows potential reentrant circuits to form under certain conditions, such as AV nodal reentrant tachycardia, where the impulse can travel down the slow pathway and return up the fast pathway.