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The period during which the ventricles are depolarizing which precedes their contraction?
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∙ 13y ago
QRS wave
Wiki User
∙ 13y ago
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What is meant by systole and diastole?
The ventricles of heart have two states: systole(contraction) and diastole (relaxation). During diastole blood fills the ventricles and during systole the blood is pushed out of the heart into the arteries. The auricles contract anti-phase to the ventricles and chiefly serve to optimally fill the ventricles with blood.http://www.answers.com/systole
What is miocardia?
Miocardia is the decreasing heart volume during systolic contraction. The rhythmic contraction of the heart, especially the ventricles, via which the blood is returned/ pushed through the aorta and pulmonary artery after each diostole.
Describe how heart contraction and relaxation influence coronary blood flow?
When relaxation or diastole is occurring in the atria blood flows through the atria and the AV valves into the ventricles. When contraction or systole is occurring in the atria the remaining blood that doesn't flow through during relaxation is pushed into the ventricles. As the atria relax, the ventricles begin contracting; ventricular pressure rises, closing the AV valves. Ventricular pressure continues rising until it exceeds the pressure in the large arteries stemming from the ventricles. The SL valves are forced open and blood is expelled from the ventricles into the aorta and pulmonary trunk. During this phase the ventricles relax because the blood is no longer compressed in their chambers. Blood expelled into the aorta and pulmonary trunk backflows toward the heart, which then closes the SL valves. During the ventricle contraction the atria stays in relaxation, filling with blood and when blood pressure on the atrial side of the AV valves exceeds that in the ventricles, the AV valves are forced open and ventricular filling begin all over again.
What happens to A V valves during ventricular contraction?
As the ventricles of the heart contract the pressure in the ventricles rises beyond that of the atria. This pressure differential causes the AV valves to shut.
What are the bands of tissue on the atrioventricular valves of the ventricles?
The chordae tendinae are fibrous bands of tissue extending from the papillary muscles in the ventricles to the cusps of the AV valves (tricuspid and mitral). They serve to prevent the leaves of the valves from being pushed into the atria during ventricular contraction, preventing backward flow of blood in the heart.
When is blood ejected from the ventricles?
during the systole phase of the heart contraction.
What is meant by systole and diastole?
The ventricles of heart have two states: systole(contraction) and diastole (relaxation). During diastole blood fills the ventricles and during systole the blood is pushed out of the heart into the arteries. The auricles contract anti-phase to the ventricles and chiefly serve to optimally fill the ventricles with blood.http://www.answers.com/systole
When do the bicuspid valves open and close?
The bicupid and tricuspid valves close during ventricular contraction. This prevents the backflow of blood from the ventricles to the atria.
What happens to A-V valves during ventricular contraction?
As the ventricles of the heart contract the pressure in the ventricles rises beyond that of the atria. This pressure differential causes the AV valves to shut.
What is miocardia?
Miocardia is the decreasing heart volume during systolic contraction. The rhythmic contraction of the heart, especially the ventricles, via which the blood is returned/ pushed through the aorta and pulmonary artery after each diostole.
what does atrioventricular valve do?
The atrioventricular valve acts as a control device between the atria and the ventricles. They prevent blood from moving back into the atria during contraction.
How do diastolic and systolic phases of the heart differ?
Diastole is the relaxation of the cardiac muscles after having contracted and pumped out the blood into the arteries.Systole is the contraction of the ventricles of the heart which pushes the blood out of the heart.
Describe how heart contraction and relaxation influence coronary blood flow?
When relaxation or diastole is occurring in the atria blood flows through the atria and the AV valves into the ventricles. When contraction or systole is occurring in the atria the remaining blood that doesn't flow through during relaxation is pushed into the ventricles. As the atria relax, the ventricles begin contracting; ventricular pressure rises, closing the AV valves. Ventricular pressure continues rising until it exceeds the pressure in the large arteries stemming from the ventricles. The SL valves are forced open and blood is expelled from the ventricles into the aorta and pulmonary trunk. During this phase the ventricles relax because the blood is no longer compressed in their chambers. Blood expelled into the aorta and pulmonary trunk backflows toward the heart, which then closes the SL valves. During the ventricle contraction the atria stays in relaxation, filling with blood and when blood pressure on the atrial side of the AV valves exceeds that in the ventricles, the AV valves are forced open and ventricular filling begin all over again.
What happens in the heart during Systole?
During systole the thick muscular walls of the ventricles contract. This happens to both sides of the heart at about the same time.The contraction of the ventricular muscle raises the pressure in the ventricle. The high pressure in the ventricle forces the bicuspid valve to close and forces blood up the aorta.
During which phase of the cardiac cycle do the ventricles relax and fill with blood?
diastole is when all 4 chambers of the heart are at rest after a cardiac cycle systole is the term used to describe the heart during a contraction
What happens to A V valves during ventricular contraction?
As the ventricles of the heart contract the pressure in the ventricles rises beyond that of the atria. This pressure differential causes the AV valves to shut.
What heart valves are closed during systole?
In late diastole (relaxation phase), the semilunar (pocket) valves close, due to decreasing arterial pressure, to prevent blood flowing back into the ventricles. These stay closed during atrial systole. (But open again during ventricular systole.)Then, as the ventricles contract during ventricular systole, the bicuspid and tricuspid valves close to prevent blood from flowing back to the atria.So, it really depends on which phase of the contraction we are looking at.(Ed: format)
