Week9 Draft5

The partial pressure of oxygen moves via concentration gradient towards areas of lesser oxygen in the body. When a breath is inhaled, the partial pressure is at its highest. In mammilian systems, the lungs take oxygen via a universal pool of oxygen and other gasses. Oxygen is trasported into the bloodstream, where the partial pressure of oxygen is significantly lower than the partial pressure of oxygen found in the inhaled breath. This causes the oxygen to diffuse into the blood stream where it is transported throughout the body. Cells that are oxygen deprived pick up oxygen from red blood cells that will eventually return to the lungs. Therefore, the blood returning to the lungs have the least partial pressure of oxygen, and the blood leaving from the lungs will have a higher partial pressure. However, in mammilian systems, the exhaled air will have a greater partial pressure of oxygen compared to the oxygenated blood because most of the oxygen we inhale is not transferred efficiently into the system.