question no. 19

Asked by itsmepreeti97 | 14th Jun, 2020, 05:40: PM

Expert Answer:

ECG or electrocardiogram is the graphical representation of the electrical activity of the heart during a cardiac cycle. 
The instrument used to obtain ECG is called an electrocardiograph.
P wave:
  • It represents the electrical excitation generated by the SA node which causes the depolarisation of the atria.
  • Interval PQ represents the atrial systole.
QRS complex:
  • It represents the spread of impulse of contraction from the AV node to the walls of the ventricles which causes depolarisation of the ventricles.
  • RS of the QRS complex and ST indicates a ventricular systole.
  • One can determine the heartbeatrate of an individual by counting the number of QRS complexes.
  • It represents the repolarisation or relaxation of ventricles.
  • The end of the T-wave marks the end of systole.

Answered by Sheetal Kolte | 14th Jun, 2020, 08:23: PM