The American journal of physiology
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A systems analysis of intrinsic regulation of intestinal blood flow and oxygenation is presented. The model is based on current concepts of metabolic control of tissue oxygen delivery and incorporates recent data from the literature regarding the influence of oxygen availability-to-demand ratio on intestinal vascular resistance and perfused capillary density. ⋯ However, the combination of capillary recruitment and blood flow autoregulation provides a large margin of safety against tissue hypoxia in the intestine. Simulation results also predict that oxygen extraction plays a greater role than blood flow in providing additional oxygen to the hypermetabolic intestine irrespective of which control system (resistance or exchange vessel) is operating.