Draw a standard ECG and explain the different segments in it. | NCERT solution | Class 11 Biology | Unit-18 Body Fluids and Circulation



Q.14:- Draw a standard ECG and explain the different segments in it.

 

Answer:-

Each peak in the ECG is identified with a letter from P to T (PQSRT) which corresponds to a specific electrical activity of the heart.

The P-wave represents the electrical excitation or depolarization of the atria. Depolarisation of atria leads to atricular systole.

The QRS complex represents the depolarization of the ventricles which initiates ventricular systole.



The T-wave represents the return of the ventricles from excited to normal state (repolarisation). The end of T-wave marks the end of systole.