The Heart and Blood Vessels
The heart is an organ that pumps blood around the body in a double circulatory system. The right ventricle pumps blood to the lungs where
gas exchange takes place. The left ventricle pumps blood around the rest of the body. You need to know the main parts of the heart and the associated blood vessels.
The natural resting heart rate is controlled by a group of cells located in the right atrium that act as a pacemaker. Artificial pacemakers are
electrical devices used to correct irregularities in the heart rate.
The Blood Vessels
The body contains three different types of blood vessel: