The cardiac cycle

The heart pumps blood to deliver oxygen and glucose to muscles and to take carbon dioxide away.

Right side -deoxygenated blood

1. Vena cava

2. Right atrium

3. Right ventricle

4. Pulmonary artery

5. Lungs

Left side -oxygenated blood

1. Pulmonary vein

2. Left atrium

3. Left ventricle

4. Aorta

5. Rest of the body

Diastole - heart relaxes and fills with blood.

Systole - heart contracts, pumping blood out.