bloodstream

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In animals, the means of carrying substances around the body. Oxygen needed by the cells of the body for respiration is absorbed into the blood at the lungs by diffusion and is transported to every part of the body by the blood stream. The oxygen is carried by specialized cells – the red blood cells. Inside each cell there are lots of haemoglobin molecules, which can combine with oxygen and release it when it is needed. Cells that respire produce carbon dioxide. The blood stream carries carbon dioxide from cells to the lungs where it is lost from the body by diffusion. The bloodstream also has an important role in carrying food around the body to cells that need it. This food is absorbed into the blood following digestion in the gut.

The Pillars of Hercules represent the promontories of Gibraltar and Ceuta. The shield represents the regions of Castile, Léon, Aragón, Navarre, and Granada. Effective date: 18 December 1981. >>