The physics paper went good,but i couldn't understand the lens question completely.i didn't know how to answer the question properly,but I still did it,tried! 
can someone please make me understand the systemic and pulmonary circulation of heart completely.Look,I know that deoxygenated blood passes from the right atrium to the right ventricle when the tricuspid valve contracts.Then it passes through the pulmonary arteries which carries this blood to the lungs when the semi lunar valves contract and the tricuspid valve closes.The deoxygenated blood at the lungs makes it oxygenated and this blood is carried by pulmonary veins to the left atrium of the heart when the bicuspid valve contracts.
Now the systemic circulation starts in which the left atrium's blood is pushed into the left ventricle.From here this oxygenated blood flows through the main artery which is the aorta to the HNGGL (head,neck,gonads,gut and limbs).Oxygenated blood is also carried from the gut to the liver by the hepatic portal vein.It is carried directly to the liver by hepatic artery and to the kidneys by the renal artery.Aorta carries the blood to the other parts (HNGGL) as I specified before.The oxygenated blood is carried by the vena cavae, hepatic vein and renal vein to the right atrium of the heart.As soon as it reaches the right atrium this marks the start of pulmonary circulation again.
I can't understand two things: what does it mean when the valves contract or relax.Like,for instance when we say the tricuspid or biscuspid valve contracts or relaxes what exactly do we mean,do they allow flow of blood or what?
secondly,what does it mean by deoxygenated?does it mean it it without oxygen because the "de" is there.And also,what does oxygenated blood mean?
Please someone help me fast
can someone please make me understand the systemic and pulmonary circulation of heart completely.Look,I know that deoxygenated blood passes from the right atrium to the right ventricle when the tricuspid valve contracts.Then it passes through the pulmonary arteries which carries this blood to the lungs when the semi lunar valves contract and the tricuspid valve closes.The deoxygenated blood at the lungs makes it oxygenated and this blood is carried by pulmonary veins to the left atrium of the heart when the bicuspid valve contracts.
Now the systemic circulation starts in which the left atrium's blood is pushed into the left ventricle.From here this oxygenated blood flows through the main artery which is the aorta to the HNGGL (head,neck,gonads,gut and limbs).Oxygenated blood is also carried from the gut to the liver by the hepatic portal vein.It is carried directly to the liver by hepatic artery and to the kidneys by the renal artery.Aorta carries the blood to the other parts (HNGGL) as I specified before.The oxygenated blood is carried by the vena cavae, hepatic vein and renal vein to the right atrium of the heart.As soon as it reaches the right atrium this marks the start of pulmonary circulation again.
I can't understand two things: what does it mean when the valves contract or relax.Like,for instance when we say the tricuspid or biscuspid valve contracts or relaxes what exactly do we mean,do they allow flow of blood or what?
secondly,what does it mean by deoxygenated?does it mean it it without oxygen because the "de" is there.And also,what does oxygenated blood mean?
Please someone help me fast
