So, GHRH is released by the hypothalamus. It travels down the portal veins into this capillary bed system that basically causes these endocrine cells to release our growth hormone. Now, the human growth hormone basically stimulates almost all the cells in our body. And what it does is the following. It basically causes the non growing cells of the body to stop using glucose as the energy store, as the energy fuel. And it causes these cells to use fatty acids instead to basically create ATP.