Corpus: Seminiferous tubules

The seminiferous tubules are part of the male reproductive system, specifically located within the testis, and are responsible for sperm production.

There are two types of seminiferous tubules, categorized by their shape:

2.1. Convoluted seminiferous tubules

The convoluted seminiferous tubules (tubuli seminiferi contorti) are the coiled tubules of the testis, predominantly found in the outer regions of the testis. They make up the bulk of the testicular parenchyma. When straightened, each tubule would be approximately 50-60 cm in length.

The seminiferous tubules are lined with a germinal epithelium composed of two cell types:

• Sertoli cells: These supporting cells form the actual epithelial tissue.
• Germ cells: These are found at various stages of spermatogenesis, with their differentiation increasing from the basal to the luminal side. Mature sperm cells develop from the spermatogonia.

The seminiferous tubules are encased by a basement membrane. Outside the basement membrane are myofibroblasts, whose contractions help propel sperm toward the rete testis.

2.2. Straight testicular tubules

The straight testicular tubules (Tubuli seminiferi recti), connect the coiled seminiferous tubules to the rete testis. These tubules are lined with a single-layered epithelium that no longer contains germ cells.

2.3. Course sequence

• Convoluted seminiferous tubules
  • Straight testicular tubules
    • Rete testis
      • Efferent ducts
        • Epididymal duct
          • Deferent duct
            • Ejaculatory duct
              • Urethra

The total length of all the seminiferous tubules in the testis combined is approximately 300 to 320 meters.