Zoology - Body Fluids and Circulation Question with Solution | TestHub

Various waves are observed in a normal ECG:

I. P-wave: It represents the electrical excitation (or depolarization) of the atria, which leads to the contraction of both the atria (atrial systole).

II. QRS complex: It represents the depolarization of the ventricles initiating the ventricular contraction. The starting of ventricular contraction (or beginning of the systole) starts shortly after Q.

III. T-wave: It represents a phase in which the ventricles return from excited to a normal state (repolarisation). The end of the T-wave marks the end of ventricular systole.