Brainlag PlusThe double circulation, the path of blood through the heart, arteries, veins and capillaries, the parts of the blood and cardiac output.
A double pump
Humans have a double circulatory system: the right side of the heart pumps deoxygenated blood to the lungs, and the left side pumps oxygenated blood to the body.
Blood goes through the heart twice on each trip round the body.
- Body → vena cava → right atrium → right ventricle → pulmonary artery → lungs
- Lungs → pulmonary vein → left atrium → left ventricle → aorta → body
- Valves stop blood flowing backwards.
- The left ventricle has the thickest wall: it pumps blood all round the body.
- Coronary arteries supply the heart muscle itself with oxygen.
- Cells in the right atrium act as a natural pacemaker; an artificial pacemaker corrects an irregular rhythm.
The pulmonary artery carries deoxygenated blood. Arteries carry blood away from the heart, whatever is in it.
The rest of this lesson and its 13 practice questions are in Plus.
Screen 1 of 4, free to read.
- 13 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards