Posted: December 1st, 2016

Describe the changes in membrane structure and ion flux which are responsible for each phase of the slow response action potential.

• The following questions need to be answered. I don’t have a work limit that is needed. I just need the questions to be answered accuately. I would estimate it could take 4 pages.

1. Describe the changes in membrane structure and ion flux which are responsible for each phase of the slow response action potential.
2. Describe the effect of calcium channel blockers (verapamil and nifedipine) on the slow response action potential.
3. Describe the mechanism of action potential propagation in cardiac muscle fibers including the role of the intercalated disc in the process.
4. Define the terms: automoticty, rhythmicity, and pacemaker.
5. Describe the origin, structure and function of the S. A. node.
6. Describe the ionic basis of automoticity.
7. Describe the conduction of the cardiac excitation impulse through the atria and explain why it does not pass directly into the ventricles.
8. Describe the structure and function of each of the following parts of the A. V. node: AN region, N region, NH region.
9. Describe the ventricle conducting system and explain the sequence of cardiac excitation and contraction.