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Ventricular systole is the contractions, following electrical stimulations, of the ventricular syncytium of cardiac muscle cells in the left and right ventricles. Contractions in the right ventricle provide pulmonary circulation by pulsing oxygen-depleted blood through the pulmonary valve then through the pulmonary arteries to the lungs.
This function is so significant to normal functioning of the circulatory system that the cardiovascular centre is considered a vital centre of the medulla oblongata. [ 2 ] [ 3 ] Hormones like epinephrine and norepinephrine can affect the cardiovascular centre and cause it to increase the rate of impulses sent to the sinoatrial node , resulting ...
Consequently, this initial phase of ventricular systole is known as isovolumic contraction, also called isovolumetric contraction. [ 1 ] In the second phase of ventricular systole, the ventricular ejection phase, the contraction of the ventricular muscle has raised the pressure within the ventricle to the point that it is greater than the ...
Normally the heartbeat is initiated in the SA node of the atrium but initiation can also occur in the Purkinje fibres of the ventricles, giving rise to premature ventricular contractions, also called ventricular extra beats. When these beats become grouped the condition is known as ventricular tachycardia.
Electrical waves track a systole (a contraction) of the heart. The end-point of the P wave depolarization is the start-point of the atrial stage of systole. The ventricular stage of systole begins at the R peak of the QRS wave complex; the T wave indicates the end of ventricular contraction, after which ventricular relaxation (ventricular diastole) begins.
These form the ventricular system of the brain: [8] The neural stem cells of the developing brain, principally radial glial cells, line the developing ventricular system in a transient zone called the ventricular zone. [9] The prosencephalon divides into the telencephalon, which forms the cortex of the developed brain, and the diencephalon.
During the ventricular contraction portion of the cardiac cycle, the Purkinje fibers carry the contraction impulse from both the left and right bundle branch to the myocardium of the ventricles. [5] This causes the muscle tissue of the ventricles to contract.
Ventricular fibrillation – Ventricular fibrillation is fibrillation of the ventricles of the heart. Rhythmic contraction is necessary for efficient movement of blood, and fibrillation disrupts this rhythm sufficiently to cause cardiac arrest. Disorders of the myocardium. Cardiomyopathy – Cardiomyopathy is a deterioration of the myocardium ...