See how to take your pulse . See five ways to take your pulse . Look at a comparison of two heart x-ray images . Watch a video of echocardiograms . Look at a picture of an echocardiography machine .
Electrocardiography uses electrical impulses to monitor the heart .
Listen to the heartbeats . Learn about the fascinating fluid of life . The red blood cells supply oxygen . The white blood cells attack foreign bodies . Don't underestimate the importance of plasma .