High School

Place the events in order for the initiation and conduction of an action potential (AP):

1. SA node fires AP.
2. AP reaches the AV node via gap junctions.
3. AP is delayed at the AV node.
4. AP travels down the bundle branches.
5. AP travels up the Purkinje fibers.

Answer :

Final answer:

The correct sequence of the events is: SA node fires AP, AP reaches AV node via gap junctions, AP is delayed at the AV node, AP travels down the bundle branches, and finally, AP travels up the Purkinje fibers.

Explanation:

The sequence of events in this conduction process, often known as the cardiac cycle, can be organized as follows:

  1. SA node fires AP: The sinoatrial (SA) node initiates the action potential, which sweeps across the atria.
  2. Ap reaches AV node via gap junctions: This impulse reaches the atrioventricular node, through specialized internodal pathways.
  3. AP is delayed at the AV node: After reaching the atrioventricular node, the impulse is delayed for about 100 milliseconds. This delay allows for the atria to complete pumping blood into the ventricles.
  4. AP travels down the bundle branches: Following this delay, the impulse travels through the atrioventricular bundle and right and left bundle branches reaching the Purkinje fibers and the right papillary muscle.
  5. AP travels up the Purkinje fibers: From the bundle branches, the action potential penetrates the ventricular muscles via the vast network of Purkinje fibers, leading to contraction of the ventricles.

Learn more about Cardiac Cycle here:

https://brainly.com/question/30640747

#SPJ11

Other Questions