2.66 understand the general structure of the circulation system to include the blood vessels to and from the heart, the lungs, the liver and the kidneys

The circulation system is responsible for getting blood to cells in order that useful substances (e.g. glucose and oxygen) can be delivered and waste (such as carbon dioxide) can be removed. It's probably best to remember where everything goes then you will just have to recall the diagram in your head should you need to know where anything goes etc...

- The pulmonary vein takes oxygenated blood from the lungs to the left atrium (which pumps it into the left ventricle)

- The oxygenated blood then travels through the aorta from the left atrium (heart) into the brain, and also around the body, including the liver, gut and kidney

- The aorta ‘transforms’ into the hepatic artery when transporting blood to the liver, and the renal artery when transporting blood into the kidneys. (NOTE: when travelling to the gut it 'transforms' into the mesenteric artery, but we dont need to know this at iGCSE level)

- The hepatic portal vein will take blood from the gut to the liver.

- On going back into the heart, the renal vein takes the deoxygenated blood from the kidney, the hepatic vein takes the deoxygenated blood from the liver, these both ‘transform’ into the vena cava. (the vena cava also take deoxygenated blood from the brain)

- The vena cava takes deoxygenated blood into the right atrium (which pumps it into the right ventricle)

- The pulmonary artery takes deoxygenated blood from the right ventricle into the lungs to be oxygenated

THE END :) (the process repeats, it takes about 1 minute for this cycle to be completed)

NOTE: It might be easier to learn this if you know an easy way to remember which veins/arteries go where. Just remember that ‘pulmonary’ is anything to/from the lungs, ‘hepatic’ is anything to/from the liver, ‘renal’ is to/from the kidneys. Aorta is an Artery, Vena cava is a Vein.

Photo credit: BBC