Sertoli cells are nurse cells or sustentacular cells present in the testes. These are present inbetween the spermatogonia. These cells are nurse cells as they provide nourishment to the developing sperms. Apart from this, they have many other functions. These cells also bring about release of Androgen binding protein (ABP) whch binds with the testosterone. These cells also form the blood testis barrier that helps to maintain luminal environment for sperm production. Semen is a mixture of Sperms and Secretions of accessory glands. Sertoli cells do not contribute to the formation of semen.