In a standard ECG, which one of the following alphabets is the correct representation of the respective activity of the human heart?
Correct answer: C. P - depolarization of the atria
- A. P - start of systole
- B. T - end of diastole
- C. P - depolarization of the atria
- D. R - repolarisation of the ventricles
Explanation
The P wave in a standard ECG represents the depolarization of the atria. The atria are the upper chambers of the heart. Depolarization is the process of electrical stimulation that causes the muscle cells in the atria to contract. The P wave is a small, rounded wave that occurs at the beginning of the ECG tracing. It is followed by the QRS complex, which represents the depolarization of the ventricles. The ventricles are the lower chambers of the heart. The P wave is caused by the spread of an electrical impulse from the sinoatrial node, which is the heart's natural pacemaker. The sinoatrial node is located in the right atrium.The P wave is important because it helps to coordinate the contraction of the atria. When the atria contract, they pump blood into the ventricles.
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