Final answer:
The circulatory loop between the heart and lungs is called the pulmonary circulation. It is responsible for oxygenating blood in the lungs and then returning it to the heart, making it distinct from the systemic circulation which distributes blood throughout the body.
Step-by-step explanation:
The circulatory system that loops between the heart and lungs is called the pulmonary circulatory system.
The pulmonary circulation is one of the three main types of blood circulation, the other two being systemic and coronary circulations. The main function of the pulmonary circulation is to transport deoxygenated blood from the right side of the heart to the lungs. Once in the lungs, the blood picks up oxygen and releases carbon dioxide, effectively becoming oxygenated. This oxygen-rich blood then returns to the left side of the heart via the pulmonary veins. In contrast, the systemic circulation carries oxygenated blood from the left ventricle through the aorta to the rest of the body, delivering nutrients and oxygen, while collecting waste products and carbon dioxide. It then returns deoxygenated blood back to the right atrium through the veins.
Understanding the difference between veins and arteries is also relevant to circulatory system functions. Veins carry blood towards the heart, while arteries carry blood away from the heart. The heart itself can be considered as two pumps in one; the right side pumps deoxygenated blood to the lungs, and the left side pumps oxygenated blood to the body. A capillary is a small blood vessel where gas exchange occurs.