Heartbeat
At rest, your heart beats approximately 60 to 100 times a minute. A child's heart rate is higher than an adults heart rate. In an average lifetime, a heart will beat around 3 billion times.
When you are physically active, excited or ill, your heart rate can rise significantly. This is a natural response to these situations.
There are two parts to each heartbeat. The first part, when the heart contracts and pumps blood, is called the 'systole' (sis-tol). The second part, when the heart relaxes so the chambers can
refill with blood, is called 'diastole' (di-as-tol).
Pulse
Every heartbeat results in blood moving forward through your arteries. You can feel this movement as a 'pulse' by placing two fingers over the artery of your wrist. Your pulse rate tells
you how fast your heart is beating.
Circulation
Your body has a network of blood vessels called 'arteries', 'veins' and 'capillaries', which carry the blood pumped by your heart. Your heart and these blood vessels make up your 'circulatory system'.
Arteries carry blood away from your heart. The largest artery in your body is called the 'aorta'. It has branches that carry blood to your head, arms and legs, and organs in your chest and abdomen.
The first branches of the aorta are the 'coronary arteries'. These run back to the outside surface of your heart to form a network of smaller arteries that supply your heart muscle with oxygen and nutrients.
Smaller branch arteries feed into even smaller blood vessels called 'capillaries', which cannot be seen with the naked eye. Oxygen and nutrients pass into body tissues from the capillaries, and then
veins carry blood back to your heart.
