Gut: The Inside Story of Our Body's Most Under-Rated Organ

by Giulia Enders

Each individual villus contains a tiny blood vessel — a capillary — that is fed with the absorbed molecules. All the small intestine’s blood vessels eventually come together and carry the blood to the liver, where the nutrients are screened for harmful substances and toxins. Any dangerous substances can be destroyed here before the blood passes into the main circulatory system. If we eat too much, this is where the first energy stores are created. The nutrient-rich blood then flows from the liver directly to the heart. There, it receives a powerful push and is pumped to the countless cells of our body. In this way, a sugar molecule can end up in a skin cell in your right nipple, for example, where it is absorbed and then ‘burnt’ along with oxygen. That releases energy which the cell uses to stay alive, with heat and tiny amounts of water created as by-products. This happens inside so many cells at the same time that the heat produced keeps our body at a constant temperature of 36 to 37 degrees centigrade.