| A | B |
| Pulmonary artery | Takes blood from heart to lungs |
| Pulmonary vein | Takes blood from lungs to heart |
| Valves | Found in veins and the heart |
| Left ventricle | Pumps blood to the body |
| Aorta | Artery leaving the left ventricle |
| Right atrium | Gets blood from the vena cava |
| Vena cava | Takes blood from body to heart |
| Capillaries | Carry blood from arteries to veins |
| One cell | Thickness of capillary wall |
| Elastic fibres | Lots found in artery wall |
| Oxygen | Gas diffusing into cells from capillaries |
| Carbon dioxide | Gas diffusing into capillaries from cells |
| Glucose | Food molecule diffusing into cells from capillaries |
| Small intestine | Where the blood absorbs glucose |
| Coronary artery | Takes oxygen to the heart muscle |
| Muscle | What the heart is made of |
| Tendons | Stop heart valves turning inside out |
| William Harvey | Worked out that capillaries must exist |
| Arteries | Vessels with thick elastic, muscular walls |
| Veins | Low pressure vessels returning blood to heart |