5. Describe the structure of a seminiferous tubule.
Answers
The seminiferous tubules are long U-shaped tubules which form their U-turn at the periphery of the testis as both distal ends drain toward the central superior and posterior regions of the testis into the rete testis, which has a flat cuboidal epithelium.
Structure of seminiferous tubules:
Seminiferous tubules are found in the testicular lobules and are highly coiled structures. It is here that the production of sperms in the testes occurs
Each of the seminiferous tubule has a lining of germinal epithelium
On the inner side, it is lined by two types of cells – sertoli cells and spermatogonia
Spermatogonia – they are the male germ cells that produce the primary spermatocytes through the process of meiotic divisions. The primary spermatocytes furthermore undergo meiotic divisions for the formation of secondary spermatocytes and ultimately spermatids. Later on, spermatids metamorphosize into the male gametes termed as spermatozoa
Sertoli cells are referred to as nurse cells of the testes. It is because they nourish the germ cells.
Just adjacent to the seminiferous tubules, there are large polygonal cells referred to as leydig cells or interstitial cells which secrete testosterone – the male hormone.