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. Now let's move on to our second organ, the heart. So the heart is basically an organ that consists of our cardiac muscle cells, also known as cardiac MIT. Now, special types of cardiac MIT located in the atria region of our heart, in the upper chambers of the heart, basically are responsible for releasing an important type of peptide hormone known as the atrial natriuretic peptide or amp.