Hypoxia and oxidative stress: The role of the anaerobic gut, the hepatic arterial buffer response and other defence mechanisms of the liver

Figure 1 Schematic diagram of countercurrent blood flow within the small intestinal villus allowing diffusion of O₂ from the arteriole to the venule, creating a luminal hypoxia from the crypt to the villous tip. PO₂ is shown in mmHg.