Question
Identify the cause of each of these waves represented in the diagram in order of their numbering?
| A. |
Atrial contraction, Isovolumetric contraction & Ejection phase
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| B. |
Ventricular contraction, Isovolumetric contraction & Atrail relaxation
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| C. |
Atrial relaxation, Isovolumetric contraction & Ejection phase
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| D. |
Atrial relaxation, Isovolumetric relaxation & Ventricular relaxation
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Show Answer
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Correct Answer � A
Explanation
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Ans. A. Atrial contraction, Isovolumetric contraction & Ejection phase.
- Wave 1 is “a” wave, Wave 2 is “c” wave & Wave 3 is “v” wave –
- The “a” wave of the atrial pressure curve is caused by atrial contraction.
- The “c” wave occurs during isovolumetric contraction and is caused by bulging of the mitral valve back into the left atrium as the ventricle attempts to contract against a fixed volume.
- The “v” wave occurs during the ejection phase of the cardiac cycle as left atrial pressure rises slowly while venous return from the pulmonary circulation fills the atrium
