The epithelium of the tubule consists of sustentacular or Sertoli cells, which are tall, columnar type cells that line the tubule.
In between the Sertoli cells are spermatogenic cells, which differentiate through meiosis to sperm cells. Sertoli cells function to nourish the developing sperm cells. They secrete testosterone binding protein, which increases the concentration of testosterone inside the seminiferous tubules. Embryologically, they also secrete the Anti-Mulleran Factor necessary for the female mulleran ducts to regress.
There are two types: convoluted and straight, convoluted toward the lateral side, and straight as the tubule comes medially to form ducts that will exit the testis.
The seminiferous tubules are formed from primitive sex cords. It is the medullary cords which develop into the seminiferous tubules and the cortical cords regress. The cords were formed from the gonadal ridge.