QRS is related to

Options

A. SA more activation
B. atrial relaxation
C. atrial contraction
D. ventricular contraction

Answer

**Step-by-Step Solution:**

1. **Understanding the QRS Complex**: The QRS complex is a part of an electrocardiogram (ECG or EKG) and consists of three distinct waves: the Q wave, the R wave, and the S wave.

2. **Function of the QRS Complex**: The primary function of the QRS complex is to represent the electrical activity associated with the depolarization of the ventricles of the heart.

3. **Ventricular Depolarization**: Depolarization is the process by which cardiac muscle cells become electrically activated, leading to contraction. Therefore, the QRS complex indicates that the ventricles are being activated.

4. **Result of Ventricular Depolarization**: As a result of ventricular depolarization, the ventricles contract, which is essential for pumping blood out of the heart to the lungs and the rest of the body.

5. **Identifying the Correct Option**: Given the options:
- a. S.A. node activation
- b. Atrial relaxation
- c. Atrial contraction
- d. Ventricular contraction

The correct answer is option D, as the QRS complex is specifically related to ventricular contraction.

**Final Answer**: QRS is related to **ventricular contraction** (Option D).

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