The cardiovascular or circulatory system is designed to make sure the survival of all cells of the physique at every second and it does this by sustaining the immediate chemical atmosphere of each cell in the physique (i.e., the interstitial fluid) at a composition appropriate for that cell's normal operate. Oxygen availability is usually a limiting factor for cell survival, and it is mostly supplied to a cell by passive diffusion. As oxygen molecules diffuse into the cell, they're consumed, BloodVitals tracker so that there's a progressive fall in oxygen focus from the surface of the cell to the bottom concentration which happens at the middle of the cell. For BloodVitals insights a spherical cell with a typicaldiffusion coefficient for oxygen (≈10−5 cm2/s) and an oxygen consumption of resting skeletal muscle (≈10−2 ml O2 cm−3 min−1), the vital dimension (radius) which is just adequately provided with oxygen from the encircling medium is about 1 mm.
Thus, we find that diffusion puts an higher restrict on the size of cells in regard to their want for oxygen. 60