The circulatory pathways of the pulmonary and body circulations are different, the pathways of the pulmonary circulation are shorter than those of the body circulation, and the physiologic significance of the two differs.
The circulatory pathways of the pulmonary and corporal circulation are different. Pulmonary circulation means that blood travels from the right atrium to the right ventricle, then through the pulmonary artery to the lungs, where gas exchange is accomplished, and venous blood becomes arterial blood, which flows back into the left atrium via the pulmonary vein and then into the left ventricle.
Physical circulation is the ventricular contraction, blood output from the left ventricle, through the aorta and its branches at all levels, to reach the capillaries throughout the body, for the exchange of substances and gases in the tissues, and then through all levels of venous confluence into the superior and inferior vena cava flow back to the right atrium.
The pulmonary circulation is also known as the small circulation, and the body circulation is also known as the large circulation. The pathway of the pulmonary circulation is shorter than that of the physical circulation, and only passes through the lungs, mainly converting venous blood into oxygen-rich arterial blood. In contrast, the physical circulation has a long distance and a wide range of flow, nourishing all parts of the body with arterial blood and transporting metabolites and carbon dioxide back to the heart.