What distinguishes the pulmonary circuit from the systemic circuit?

The pulmonary circuit is distinguished from the systemic circuit primarily by its specific function of transporting deoxygenated blood from the heart to the lungs for oxygenation and then returning oxygen-rich blood back to the heart. This circuit plays a crucial role in gas exchange, as it is in the lungs that carbon dioxide is expelled from the blood, and oxygen is absorbed, which is essential for maintaining the body's oxygen levels.

While the systemic circuit is responsible for delivering oxygenated blood from the heart to the rest of the body and returning deoxygenated blood back to the heart, it does not directly involve the process of gas exchange that occurs in the lungs, which is the defining characteristic of the pulmonary circuit. Understanding this distinction is key to grasping the different roles that each circuit plays in the overall circulatory system and how they contribute to homeostasis.