It's called systole,
but valve closure is a passive event caused by an attempt at retrograde blood flow.
During the compression stroke, both the intake and exhaust valves are closed. This sealing allows the piston to compress the air-fuel mixture (in gasoline engines) or air (in diesel engines) within the cylinder, increasing the pressure and temperature before ignition. The closed valves ensure that no gases escape and that the compression is efficient, setting the stage for a powerful combustion event in the subsequent power stroke.
When ventricular pressure exceeds that of the large arteries leaving the heart, the semilunar valves are forced open. (Marieb/9th edition)
The AV valves open when the blood pressure exerted on their atrial side is greater then on the ventricle side. This happens when blood returning to the heart fills the atria and puts pressure against the valve. Note : When heart is completely relaxed, the AV valve flaps hang limply into the ventricle chamber (open) allowing blood from the atria to flow through them directly to the ventricle. Thus, it is the result of ventricle contraction which closes the AV valves and moves them from their resting state (open).
The semilunar valves are open when blood is being pumped by ventricular contraction. This event is called systole.
YES!!!!!!
an account of its causes is remembering what it causes but an explanation is what it actually is not what it causes!...i think
No "event" causes that.The continuous rotation of the planet on its polar axis it responsible for the progression of day and night.
Control valves should always be in the "fail-safe" position when not actively controlled or during a system failure. This ensures that, in the event of a power loss or malfunction, the valve will default to a position that maintains safety and prevents damage to the system. The specific fail-safe position—open or closed—depends on the application and the process requirements. Proper configuration and testing are essential to ensure reliable operation.
The chordae tendenae prevents the back flow
=I have No Clue=
stressor
stimulus