Now, if we take a cross section of the testes we basically get the following diagram. And within this diagram we have a specialized section known as the Simoniferous tubules. And this is what we're going to focus on in this lecture. So these tubules, shown in brown are the Simonerfrost tubules and if we examine the microscopic section of the simoniferous tubules, we basically get the following diagram. So within our Simoner PHOs tubules we have two very important types of cells that are involved in sperm production as well as in the production of our androgens the male sex hormones. So we have sirtoli cells which are these large cells shown that contain the blue nuclei as shown.