Question
Biology Question on Circulatory Pathways
The diagram given here is the standard ECG of a normal person. The P- wave represents the :
A
End of systole
B
Contraction of both the atria
C
Initiation of the ventricular contraction
D
Beginning of the systole
Answer
Contraction of both the atria
Explanation
Solution
In ECG, P-wave represents the depolarization of atria, which leads to the contraction of both atria. T-wave represents the return of ventricles from excited to normal state. The QRS complex represents the depolarisation of the ventricles, which initiates ventricular contraction. The contraction starts shortly after Q and marks the beginning of systole.