Stomach acid is one of the harshest conditions to live in and the mucus layer is what keeps our stomach from digesting is from the inside because it forms a protective barrier so by living there, they would be protected and not exposed to the acid
Insulin helps control blood glucose levels by signaling the liver and muscle and fat cells to take in glucose from the blood. Insulin therefore helps cells to take in glucose to be used for energy. If the body has sufficient energy, insulin signals the liver to take up glucose and store it as glycogen.
They occur when a blood vessel within the skull bursts and bleeds into and around the brain. The main cause of haemorrhagic stroke is high blood pressure, which can weaken the arteries in the brain and make them prone to split or rupture. Hope this helps :/ x
The way water is cycled through the air and the atmosphere it is how we retain clean and good water in our planet.