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.
BLOOD VESSELS: Human beings have a closed type of circulatory system which means blood does not come into direct contact with body tissues. Instead, the blood flows in restricted pathways called blood vessels. Materials are exchanged between blood and body tissues through the walls of blood vessels.Thus blood vessels are pathways of blood flow in the human body. There are three main types of blood vessels; Arteries, Capillaries and Veins. Arteries pump newly oxygenated blood away from the heart and around the body.LOOD VESSELS: Human beings have a closed type of circulatory system which means blood does not come into direct contact with body tissues. Instead, the blood flows in restricted pathways called blood vessels. Materials are exchanged between blood and body tissues through the walls of blood vessels.