In $ECG$,$P$-wave represents

What does a blood pressure instrument record?

Arrange and select the following events in the correct sequence during the measurement of blood pressure by a sphygmomanometer.
$i.$ Pulsatile sound disappears.
$ii.$ Cuff is inflated to block the brachial artery by external pressure.
$iii.$ First pulsatile sound is heard indicating systolic pressure.
$iv.$ Pressure in the cuff is slowly lowered.
$v.$ Cuff is wrapped tightly around the upper arm.

In $ECG$,the $T$-wave represents:

What is represented by the $P$-wave in an $ECG$?

What is the systolic and diastolic blood pressure of a healthy individual?
Systolic Pressure $\quad$ Diastolic Pressure
$(mm\, Hg) \quad (mm\, Hg)$