Author Topic: IGCSE Biology... help?  (Read 862 times)

Offline RomanianGuy

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IGCSE Biology... help?
« on: May 16, 2009, 02:38:04 pm »
Heey guys,
can anyone give me a summary of the Cardiac Cycle? The explanation I have in my book (Longman Biology for IGCSE) is very big and confusing :/

nid404

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Re: IGCSE Biology... help?
« Reply #1 on: May 16, 2009, 03:41:04 pm »
u mean d double circulatory system right? I'll explain w8ever I can and I hope u get it.

1) Deoxygenated blood from the body is brought to the right atrium by the vena cava

2) This is pumped by the atrium to the right ventricle. The right ventricle then pushes it to the pulmonary artery.(note that the pulmonary artery is the only artery that carries deoxygenated blood.)
3) The artery carries the blood to the lungs where it is oxygenated..
4) It moves from the lungs via the pulmonary vein(the only vein carrying oxygenated blood) to the left atrium. From here it goes to the left ventricle
5) The left ventricle pumps the blood to the aorta which takes the blood to the rest of the body.

Important stuff
-There are valves in the chambers to prevent backflow. Right chamber has tricuspid valves and left side has bicuspid valves.
-the pulmonary artery has semi -lunar valves for the same reason
-Don't mix the chambers up. Here's an easy way to remember which chamber contains what. LORD(Left Oxygenated Right Deoxygenated.
-remeber that thickness of the chamber differ and pressure of blood also differs. The blood in the aorta is under high pressure because it has to carry the blood to all parts of the body. The left ventricle muscles r thicker because they need to create high pressure for blood to pass thru aorta and reach the different parts.

think this is it(and it's looooooong) but I hope this helps.
« Last Edit: May 16, 2009, 03:50:17 pm by nid404 »

Offline Mastermind

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Re: IGCSE Biology... help?
« Reply #2 on: May 16, 2009, 04:51:33 pm »
Found this on google
"Relax & take notes, Imma give you great quotes"