Right atrium
the right atrium
The purpose of systemic circulation is to carry blood from the heart to the body. It then returns the blood back to the heart.
Pulmonary - carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart. Systemic - carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart.
venae cavae
Inferior vena cavae
Blood is bright red when it returns to the heart from the lungs. It is darker red when it returns to the right atrium from the systemic circulation.
Blood enters the heart from the systemic circulation in the right atrium, and then moves to the right ventricle. From there, blood is pumped into the pulmonary circulation. When the blood returns from the lungs, it enters the left atrium, then left ventricle, then is pumped to body tissues via the systemic circulation.
The circulatory system does create, essentially, one or two large loops in the body. Blood moves from the left ventricle to the systemic arteries, then capillaries, then veins of the systemic circulation. Blood returns from the systemic circulation to the right atrium, then right ventricle, then to the pulmonary artery. It goes to the lungs and returns to the left atrium via the pulmonary veins.
Blood returning from pulmonary circulation returns to the right atrium via the pulmonary vein. Blood returning from the systemic circulation returns to the right atrium via the Vena Cava.
The inferior vena cava is a large vein. The two common iliac veins join to make the inferior vena cava, which receives blood from the lower body and empties it into the right atrium of the heart.
Blood enters the right atrium via three veins: (1) the superior vena cava returns blood from body regions superior to the diaphragm; (2) the inferior vena cava returns blood from the body areas below the diaphragm; and (3) the coronary sinus collects blood draining from the myocardium.
no
The pulmonary system carries blood low in oxygen from the heart to the lungs where it picks up oxygen and returns to the heart again. The opposite is true of the system.