Chapter 27.4, Problem 3MC

Summary Introduction

To determine:

The way in which a heartbeat originates and propagates.

Introduction:

The heart is made up of tough involuntary cardiac muscles. Blood enters and moves out of the heart through contraction and relaxation of the chambers. This process of contraction and relaxation of the chambers of the heart is known as the cardiac cycle. 1 cardiac cycle is equivalent to 1 heartbeat. A human heart beats more than 2.5 billion times in a lifetime.