So it is stimulated, it is released when we have a low concentration of calcium in the blood. And what it does is it ultimately increases the amount of calcium inside our blood by two methods. Firstly, it increases the ability of our cells in the gut and our intestines to basically absorb more calcium from our food and more phosphate ons from our food. And secondly, it also increases bone resorption, it increases the amount of bone matrix that breaks down and releases our calcium and phosphate ions into our blood. So the kidneys produce two important hormones, erythropoietin and calcitriol. And it also produces a proteolytic enzyme, Rename, that is necessary in producing angiotestin one, angiotestin two and aldosterone, as well as stimulates the release of ADH, the antidiaretic hormone, by the posterior pituitary gland.