Aspartame is the most controversial food additive in history, and its approval for use in food was the most contested in FDA history. In the end, the artificial sweetener was approved, not on scientific grounds, but rather because of strong political and financial pressure.
The arterioles then divide further into capillaries. Capillaries are the smallest blood vessels and their walls are only one cell thick which allows diffusion between the blood and cells to occur. Nutrients and oxygen from the blood diffuses through the capillary walls into the tissues that need it. This is aided by the relatively high blood pressure that also squeezes the oxygen and nutrients through the capillary wall and into the cells of the tissue.
The alveoil transport oxygen from the lungs into the circulatory system. You breathe in oxygen into your lungs. The oxygen diffuses across the thin walls of the alveoli in the lungs and the thin walls of the blood vessels in the lungs into the blood stream.he main way in which the respiratory and the circulatory system work together is that the heart send blood to the lungs, which is then oxygenated, so the blood can then be sent to the rest of the body (after being pumped back through the heart).