The upper chambers of the heart are called_________.

Lead I is formed by which two locations?

The human heart has ______ chambers.

Where is ground sensor located?

Oxygen rich blood flows from the lungs into what chamber?

The inside of the membrane which is negatively charged.

How many openings are there in the right atrium?

aVR ,aVL, and AVF

Carbon dioxide rich blood enters the heart through which chamber?

Two different changes being measured in two directions.