The seminiferous tubules are thin tubular structures within the testes where sperm germinate and mature. They are made up of column-shaped sertoli cells surrounded by spermatogenic cells on the inside and stem cells on the outside.
It’s estimated that there are between 600 and 800 seminiferous tubules making up the main part of each testis parenchyma. Each individual tubule is thought to be roughly 20 to 24 inches, so a single testis may contain approximately 985 feet of tubules.
More About Seminiferous Tubules
The stem cells on the outside of the seminiferous tubules divide in a process called mitosis. They then move inside the seminiferous tubules, where they attach to the internal walls and transform into germinal sperm cells known as spermatogonia. This process, where sex cells are created, is known as meiosis.
These cells take approximately two months to flow through the seminiferous tubules until they reach the epididymis, where they are stored on the stored on the exterior of the testes. During this journey through the seminiferous tubules, the cells receive nutrients which help them grow into mature primary sperm cells, or spermatozoa. They do not have the tails they need for motility on exiting the seminiferous tubules, but they are almost mature.
Because meisosis, or the creation of sex cells, occurs in the seminiferous tubules, these tubules are an essential part of the reproductive process.