right atrium pumps blood to venous circulation when it contracts.
right atrium pumps blood to venous circulation when it contracts.
where does right atrium pump blood when it contracts?
venous circulation
atrium (heart)









































the atrium (latin ātrium, “entry hall”), is the upper chamber through which blood enters the ventricles of the heart. there are two atria in the human heart – the left atrium receives blood from the pulmonary (lung) circulation, and the right atrium receives blood from the venae cavae (venous circulation). the atria receive blood while relaxed (diastole), then contract (systole) to move blood to the ventricles. all animals with a closed circulatory system have at least one atrium. humans have two atria.
atrium (heart)
the right heart collects deoxygenated blood from two large veins, the superior and inferior venae cavae. blood collects in the right and left atrium continuously. the superior vena cava drains blood from above the diaphragm and empties into the upper back part of the right atrium. the inferior vena cava drains the blood from below the diaphragm and empties into the back part of the atrium below the opening for the superior vena cava. immediately above and to the middle of the opening of the inferior vena cava is the opening of the thin-walled coronary sinus. additionally, the coronary sinus returns deoxygenated blood from the myocardium to the right atrium. the blood collects in the right atrium. when the right atrium contracts, the blood is pumped through the tricuspid valve into the right ventricle. as the right ventricle contracts, the tricuspid valve closes and the blood is pumped into the pulmonary trunk through the pulmonary valve. the pulmonary trunk divides into pulmonary arteries and progressively smaller arteries throughout the lungs, until it reaches capillaries. as these pass by alveoli carbon dioxide is exchanged for oxygen. this happens through the passive process of diffusion.
heart