From the exterior environment to the cytoplasm of the cell, the oxygen must first cross a plasma membrane when entering the body at an exchange surface. These exchange surfaces are connected by openings on the body's surface (i.e., the mouth) and are tightly packed to increase surface area; Thus, increasing the number of cells. The circulatory system then transports the oxygen molecule across the exchange surface via blood from the interstitial fluid to the cytoplasm of the body cell.
Work Step by Step
Figure 40.4 is found on page 869.