Answer: cardiac cycle.
- A cardiac cycle
- B menstrual cycle
- C nitrogen cycle
- D water cycle
Correct answer: A. cardiac cycle
Explanation: One heartbeat is a cardiac cycle of contraction (systole) and relaxation (diastole).
A single ECG cycle: the P wave marks atrial depolarisation (contraction signal), the large QRS complex marks ventricular depolarisation, and the T wave marks ventricular repolarisation (recovery) before the next cycle begins.
Concept context
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage.