What supplies oxygen to the blood?

The lungs are responsible for supplying oxygen to the blood through the process of respiration. When we inhale, air enters the lungs, where oxygen from the air passes through the alveoli (tiny air sacs) and into the bloodstream. This oxygen is then bound to hemoglobin in red blood cells, allowing it to be transported effectively throughout the body to various tissues and organs that require oxygen for energy production and metabolic processes.

The heart, while essential for pumping blood throughout the body, does not supply oxygen but rather circulates oxygenated and deoxygenated blood. The kidneys function to filter blood and remove waste products but are not involved in gas exchange or oxygenation. The liver primarily plays a role in metabolism, detoxification, and the production of certain proteins, but it also does not engage in oxygen supply to the blood. Thus, the lungs are the critical organ for the exchange of oxygen and carbon dioxide, making them vital for maintaining proper oxygen levels within the bloodstream.