biology

[syed]

The heart has several valves. However, I wasn't able to understand the difference between the bikuspid and the trikuspid valve. What are the differences and are the differences (if any) significant?

[gabennett]

The difference is just a question of whereabouts the valves are in the heart. The bicuspid valve is between the left atrium and the left ventricle. The left ventricle contracts, which forces blood into the aorta. As it does so, the bicuspid valve closes to prevent any of the blood going back into the left atrium. Once the left ventricle is pretty much empty, it expands. The bicuspid valve then opens to allow blood to flow through from the left atrium into the left ventricle. The tricuspid valve does the same thing between the right atrium and the right ventricle. The right ventricle pumps blood into the pulmonary artery - as it does so the tricuspid valve shuts to prevent blood flowing back into the right atrium, opening again to allow blood through once the right venticle is empty. Physically, however, the two valves are identical.

[Squirrel]

I'm not sure if this was part of the question, but the way I always remember the arrangement of the valves when looking at a horizontally-flipped heart diagram is to go from left to right and think of the phrase I see in shops sometimes "Try before you Buy!". TRIcuspid, BIcuspid. I've always been a little strange.