Oxygen transport in human tissue has been considered a process involving diffusion from the blood vessels into tissue cylinders accompanied by a zero-order reaction, (Welty et al., 1984). This reaction represents the metabolic consumption of the oxygen to produce carbon dioxide. The tissue cylinders can be considered to be arranged in a bundle such that the boundary condition at the inner surface of the tissue cylinder is a constant ci corresponding to the oxygen concentration in the arterial blood. Due to symmetry at the outer surface of these tissue cylinders, a zero flux condition can be used. 1) Formulate the steady-state governing equation and the boundary conditions for oxygen concentration, c, in the tissue. 2) Determine the oxygen concentration as a function of radius, r. 3) Determine the rate of oxygen consumption in the inner surface of the tissue at steady state