alevel biology

Hi Angelina
I’ll try my best to explain in the best possible way that I can.
1) So the DEOXYGENATED BLOOD gets into the heart through VENA CAVA ( there’s 2 types of vena cavas, we have the superior vena Cana which brings deoxygenated blood from the top portion of our body e.g brain and we have an inferior vena cava which brings deoxygenated blood to the heart from the lower part of our body e.g legs)
2) once into the heart, the deoxygenated blood gets into the right atrium, and then into the right ventricle. Between the right atrium and right ventricle we have these valves called tricuspid valves (which can be referred to as atrioventricular valves as well).

3) then the right ventricles contract and the deoxygenated blood is forced out of the heart through the pulmonary artery . We find semi lunar valves in these arteries.

4) the deoxygenated blood then goes to the lungs to pick up oxygen and goes back to the heart through the PULMONARY VEIN into the left atrium.

5) then the left atrium contracts, causing the bicuspid valves to open which are present between left atrium and left ventricle ( and these valves are also called atrioventricular valves).

6) once into the left ventricle, the left ventricle contracts forcing the oxygenated blood out of the heart through the aorta and again we also find semi lunar valves in the aorta aswell. And now the oxygenated blood goes to the rest of the body

Sorry if it’s confusing, as clearly I’m not too good with explanations but I’ve also attached a drawing of a simplified version of heart below

Best of luck for Wednesday if ur doing ocr 🤞 kinda scared