Answer: ventricles.
- A ventricles
- B the atria
- C the valves
- D the veins
Correct answer: A. ventricles
Explanation: The ventricles are the lower pumping chambers.
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.