Vitamin D is created in our skin when exposed to sunlight. As it travels through the liver and then kidneys it is converted to the hormone calcitriol. And you know hormones. They influence lots of processes in our bodies.
Patrick explains the digestive process form the mouth to, well, you know. He explains what happens to the food we eat along the way, all the body parts involved and what they do and all the enzymes and what they do. Perhaps most important he explains how our body digests food without digesting itself.
Kidneys detoxify our blood at the rate of 180 liters per day while only excreting a liter and a half. The structure of the kidney and its operational processes described here are what make the kidneys so efficient.
