Describe the structure of a seminiferous tubule.
The testis contains about 250 compartments called testicular lobules. Each lobule contains one to three highly coiled seminiferous tubules in which sperms are produced.
Each seminiferous tubule is lined on its inside by two types of cells: male germ cells (spermatogonia) and Sertoli cells.
The male germ cells undergo meiotic divisions finally leading to sperm formation, while the Sertoli cells provide nutrition to the germ cells.
The regions outside the seminiferous tubules are called interstitial spaces, which contain small blood vessels and interstitial cells or Leydig cells. Leydig cells synthesise and secrete testicular hormones called androgens.
The seminiferous tubules open into the vasa efferentia through rete testis, which then transport sperms to the epididymis.
Explanation
This answer is based on NCERT Class 12 Biology Chapter 2 (Human Reproduction). The textbook describes the seminiferous tubule structure in detail under the male reproductive system section. Key points include: location within testicular lobules, the two types of lining cells (male germ cells and Sertoli cells), their respective functions, and the surrounding interstitial spaces containing Leydig cells. The connection to vasa efferentia through rete testis completes the structural description. This comprehensive coverage addresses all structural aspects needed for a 5-mark long answer question.
Solution Steps
Step 1: Describe location - seminiferous tubules are present in testicular lobules (1-3 per lobule)
Step 2: Describe lining - two cell types: male germ cells (spermatogonia) and Sertoli cells
Step 3: Explain functions - germ cells undergo meiosis for sperm formation; Sertoli cells provide nutrition
Step 4: Describe interstitial spaces - contain Leydig cells that secrete androgens
Step 5: Mention connection - seminiferous tubules open into vasa efferentia through rete testis