Question

Place the labels in order denoting the sequence of events of the cardiac cycle beginning with resting membrane potential and ending with the beginning of repolarization. The first and last steps are given.

Answer 1

Note: Question lack information. I have added full question with answer and explanation in info-graph.

Answer:

The cycle of human heart start with end of one beat to beginning of next beat is called cardiac cycle.

Answer 2

Answer:

1. At the beginning of the cardiac cycle, the heart has the membrane potential at rest.
2. To start the cardiac cycle, SA node cells need to reach an authoritative threshold.
3. At that moment, inside the SA node cells there are many channels, which have tension regulation, fast calcium and sodium.
4. At this point, it is possible that a flow of cations occurs from within the SA node cells towards the adjacent cardiocytes through gap junctions.
5. At that moment it is possible to visualize the existence of P waves.
6. Depolarization occurs at the AV node and this depolarization allows the transmission of electrical signals to the bundle branches.
7. At this point, it is possible to visualize a downward deflection.
8. After depolarization of the AV node, the diastolic volume is reached.
9. There is the closing of the AV valves and the opening of the semilunar valves.
10. Blood is available to exit the ventricles.
11. Repolization begins.

Explanation:

Cardiac cycle is the term used to describe the events responsible for the bombardment of blood in the living organism. These processes are performed by the cardiovascular system and are extremely important to maintain life within the body.

In summary, the heart cycle occurs each time a heartbeat is performed. This cycle involves numerous phases and a large number of cells.