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.
Capillaries are tiny blood vessels connecting the small arteries (arterioles) to the small veins (venules). The blood vessels carry oxygen and nutrients to all the individual cells in the body.rteries carry blood to the tissues, and veins carry blood back to the heart. In betweenare tiny blood vessels so small that red blood cells can pass through single file, allo â¦ wingthe oxygen to diffuse into the surrounding tissue. These are called capillaries.