Describe the pathway of the action potential through the cardiac conduction system
What will be an ideal response?
Under normal conditions, the sinoatrial (SA) node generates an action potential that spreads to the atrioventricular (AV) node. Conduction slows once the action potential reaches the AV node and bundle due to a low number of gap junctions between AV nodal cells and the presence of nonconducting fibrous skeleton that surrounds the AV node. During this time, the atria depolarize and contract before the ventricles, giving the ventricles time to fill with blood. The action potential is conducted from the AV bundle to the right and left bundle branches. Depolarization spreads to the Purkinje fibers and then to the cardiac contractile muscle cells of the ventricles. As a result, the ventricles contract and blood is ejected from the heart through the aorta and pulmonary trunk.
You might also like to view...
If you have three threads laying on top of each other on a slide and you are focused on the top-most thread, then ________
A) all three threads should be in clear focus B) you are ready to rotate the ocular lens C) neither the middle nor the bottom-most thread will be in clear focus D) the middle thread will also be in clear focus
It may take nearly a half hour for rods of the retina to regenerate a full supply of photopigment during the process of
A. lateral inhibition. B. light adaptation. C. opsinization. D. dark adaptation.
What portion of the small intestine is most distal from the pylorus of the stomach?
A. jejunum B. duodenum C. ileum D. common bile duct E. hepatopancreatic ampulla
Phase IV clinical drug trials involve testing a drug only on the specific human population who have the condition that the drug is intended to treat.
Answer the following statement true (T) or false (F)