WHEN THE PRESSURE IN THE ATRIA RISES ABOVE THE PRESSURE IN THE VENTRICLES THE AV VALVES OPEN
WHEN THE PRESSURE IN THE ATRIA DROPS BELOW THE PRESSURE IN THE VENTRICLES THE AV VALVES CLOSE
WHEN THE PRESSURE IN THE VENTRICLES RISES ABOVE THE PRESSURE IN THE MAJOR ARTERIES THE SEMILUNAR VALVES OPEN
WHEN THE PRESSURE IN THE VENTRICLES DROPS BELOW THE PRESSURE IN THE MAJOR ARTERIES THE SEMILUNAR VALVES CLOSE
THANK YOU
WHEN THE PRESSURE IN THE ATRIA DROPS BELOW THE PRESSURE IN THE VENTRICLES THE AV VALVES CLOSE
WHEN THE PRESSURE IN THE VENTRICLES RISES ABOVE THE PRESSURE IN THE MAJOR ARTERIES THE SEMILUNAR VALVES OPEN
WHEN THE PRESSURE IN THE VENTRICLES DROPS BELOW THE PRESSURE IN THE MAJOR ARTERIES THE SEMILUNAR VALVES CLOSE
THANK YOU
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The best place to start with this stuff is understanding which way the valves face, or rather which way they want to stop blood flowing. The valves are there to allow blood to flow one way, and then stop back-flow. AV valves are between the atria and ventricles. Which way does blood move between them? From the atria to ventricles. Therefore, the AV valves will face from the atria to the ventricles, and stop blood going backwards (ie. ventricles to atria).
The other valves are the semilunar ones, and the only other useful place they can go is between the ventricles and outside the heart. Blood flows from the ventricles out to the aorta/pulmonary artery, so these valves will face this way to stop blood going from the aorta/pulmonary artery back into the ventricle.
If you remember what the valves are there for, you know which way they face, and then you'll know these answers. Remember blood will flow from high pressure to low pressure (water in a hose pipe is under high pressure so flows out of it).
A > V, blood from A -> V, good, so AV open.
A < V, blood from A <- V, bad, so AV close.
V > Art, blood from V -> Art, good, so SL open.
V < Art, blood from V <- Art, bad, so SL close.
So yes, you were right.
The other valves are the semilunar ones, and the only other useful place they can go is between the ventricles and outside the heart. Blood flows from the ventricles out to the aorta/pulmonary artery, so these valves will face this way to stop blood going from the aorta/pulmonary artery back into the ventricle.
If you remember what the valves are there for, you know which way they face, and then you'll know these answers. Remember blood will flow from high pressure to low pressure (water in a hose pipe is under high pressure so flows out of it).
A > V, blood from A -> V, good, so AV open.
A < V, blood from A <- V, bad, so AV close.
V > Art, blood from V -> Art, good, so SL open.
V < Art, blood from V <- Art, bad, so SL close.
So yes, you were right.