0
>Yes
No they do not.
Left ventricle contracts before the right. (From the correct anatomical position.)
That makes sense because the left ventricle has more work to do, systemic vs. pulmonary.
http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_electrical.html
Well guess what. This website is not entirely correct. Sometimes things are interpreted half right. What you want to focus on here from the EKG is the QRS complex. This is the depolarization and repolarization of the ventricles (not as they explained the firing of the left, then right ventricles). In general, you will say that the atria contract together and then the ventricles contract together. When you start splitting hairs, you can justify tiny differences in milliseconds, etc. Also, keep in mind that the left ventricle provides a much stronger contraction since it is sending out the blood to the systemic circuit, while the right goes out to the pulmonary circuit.
Wiki User
∙ 12y ago
Wiki User
∙ 12y agono if it did you would be dead
Haha, funny, but true. If this question is asking, "do the atria contract at the same time, and then the ventricles contract after at the same time" - yes, that would be correct.
Some people split hairs here and talk about how the SA node is in the right atrium, and so it fires first, and that the left ventricle has a stronger, longer contraction so it has to fire first - but this is really splitting hairs. Remember these are electrical impulses, and are meant to fire the atria pretty much at the same time, then both ventricles at the same time. Incedently, the left ventricle is a stonger, thicker part of the heart due to the demand of sending blood into the systemic circuit.
Wiki User
∙ 12y agono, the atria contract first and the signal is delayed when travelling between the gap junctions in the atria to the Av node in the apex of the ventricles, so the ventricles contract a fraction of a second later
Wiki User
∙ 9y agono they do not contract at the same time
Wiki User
∙ 14y agono
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What makes heart valves open and close?
Valves in the heart close (or open) due to pressure changes in the 4 chambers of the heart. When blood flows into the heart through the pulmonary vein (oxygenated) the heart is in diastole so both the left atrium and ventricle fill. At this point, the bicuspid valve between the chambers is open. When the left atrium becomes full of blood, stretch receptors trigger a response from the SA node - this leads to a contraction of the left atrium (bicuspid valve forced open by pressure). The pressure then exerted from the left ventricle on the left atrium causes the valve to close. This prevents back-flow into the left atrium. When the left ventricle is full, the AV node sends an impulse down the Bundle of His, and to the Prukinje fibres. The left ventricle is subsequently "squeezed" causing blood to flow up the aorta and out to the body. When the heart is contracting like this it is in Systole. Similarly, valves in the aorta close due to the pressure of the blood (caused by gravity). This, again, prevents back-flow in the heart. A similar chain of events occurs in the right side of the heart.
What time does feral heart open?
well feral heart i a noroml animal it opens in an hour
How do you explain the function of the heart valves?
enforce a one way blood flow through the heart chambersthe valves prevent the blood from going backwards. they keep the blood flowing forwards! we just dissected a heart in science today so i know for sure thats what they do :)
When your heart goes bump bump is that one or to heart beats?
It really is lubb dupp and it is the sound of the 4 valves closing, two at a time. This occurs during one heart beat.
What valves prevent blood from flowing backwards from the arteries into the heart?
All the valves of the heart prevent backflow of the blood through the heart: tricuspid valve, pulmonary valve, mitral valve, and aortic valve. Furthermore, there are one-way valves in the veins that prevent backflow of blood.
Why cant the AV and SL valves of heart be open at same time?
it would disturb pressure gradients as it would mean same amount of pressure
Why can't the AV and sl valves be open at same time?
The blood in the heart moved from one chamber to another chamber. If the AV ( artrio-ventricular valve) and SL ( semilunar valve) open at the same time, the blood will not be able to circulate and can flow backward. Thus the valves are there to stop the back-flow of blood and keep the circulation going.
When the intake and exhaust valves are both open at the same time that length of time is called?
Valve overlap.
What is meant by the term valve overlap?
There is a short time between the exhaust and intake stroke where all the valves are slightly open at the same time. This period of time is called valve overlap. This is because the intake valves are just starting to open as the exhaust valves are just finishing closing. This is done so flow through the engine can be maintained at engine operating speeds.
Are both AV valves and semilunar valves ever closed at the same time?
Yes, both valves can be closed at the same time. (Look at a cardiac cycle diagram and look at time period of around 0.45 seconds)
What stop the blood from falling back into the heart?
The valves of the heart. They're one way valves that won't allow blood to flow back into the heart, provided the heart and valves are normal. In some cases, the valves can be defective, and cause the exact 'backflow' you're asking about. These cases are rare.
What happened to the heart?
Blood first enters the atria by the veins. The walls of the atria contract, pushing blood from the atria into the ventricles through the atrioventricular valves, which are open at that time. The semilunar valves are therefore closed, so that the ventricles can fill with blood. The walls of the ventricles then contract powerfully and the blood pressure rapidly rises inside them. This first causes the atrioventricular valves to close in order to prevent back-flow of blood to the atria and then causes the semilunar valves to open, allowing blood to be pumped out into the arteries. At the same time this is occurring, the atria start to refill with blood collected from the veins. The ventricles stop contracting and as pressure falls inside them the semilunar valves close, preventing back-flow of blood from the arteries to the ventricles. When the ventricular pressure drops below the atrial pressure, the atrioventricular valves open. Blood entering the atrium from the vains then flows on to start filling the ventricles once again.
How do valves prevent blood from flowing in the wrong direction?
valves help prevent blood from flowing in the wrong direction by opening and closing at the right time to let the heart pump blood effectively.
What is slurred?
When playing a Trombone the player can make it slur. By blowing and moving the valves at the same time.
What makes heart valves open and close?
Valves in the heart close (or open) due to pressure changes in the 4 chambers of the heart. When blood flows into the heart through the pulmonary vein (oxygenated) the heart is in diastole so both the left atrium and ventricle fill. At this point, the bicuspid valve between the chambers is open. When the left atrium becomes full of blood, stretch receptors trigger a response from the SA node - this leads to a contraction of the left atrium (bicuspid valve forced open by pressure). The pressure then exerted from the left ventricle on the left atrium causes the valve to close. This prevents back-flow into the left atrium. When the left ventricle is full, the AV node sends an impulse down the Bundle of His, and to the Prukinje fibres. The left ventricle is subsequently "squeezed" causing blood to flow up the aorta and out to the body. When the heart is contracting like this it is in Systole. Similarly, valves in the aorta close due to the pressure of the blood (caused by gravity). This, again, prevents back-flow in the heart. A similar chain of events occurs in the right side of the heart.
What are cams used for?
Camshafts are generally used to open and close valves at the correct time.
How many time a minute does one of your AV valves open and close?
depends on the person
