Predict conduction velocities for the different cell types in the heart and discuss their impact on the timing of activation of the heart. The heart is two separate pumps existing in parallel. D. Blood from the pulmonary circulation returns to the left atrium heart via the pulmonary veins and during diastole drains through the mitral valve into the left ventricle. During systole blood is pumped from the left ventricle via the aortic valve into the aorta. F. Specialized muscle cells insure the proper sequence of activation.
Cardiac cycle is initiated by pacemaker activity of SA node.
The anterior interatrial myocardial pathway facilitates activation of the left atrium. Internodal conduction pathways carry activation from the SA node to the AV node. The bundle of HIS, the bundle branches, and purkinje system carry excitation from the AV node to the ventricles. G. Volume of blood pumped by the right and left sides of the heart is equal. Venous return to the heart is continuous, pools in the atria when AV valves are closed.