Biology 2402 Lab Series - Episode 6: The Testes

Overview

• Testes as Glands: Paired sex organs functioning as glands, similar to ovaries.
• Location: Situated outside the body wall in the scrotum, an extension of the abdominal pelvic cavity.

Scrotum

• Structure: Sack of skin and connective tissue holding the testes outside the body.
• Function: Keeps the testes cooler than the high mammalian body temperature, which is essential for sperm production.

Testes Structure

• Epididymis: Mentioned but not the focus of this section.
• Seminiferous Tubules:
  • Resembles spaghetti in a bag.
  • Site of spermatogenesis (sperm production).
  • Contains nurse cells/Sertoli cells (not required for identification) which produce inhibin.

Hormones

• Interstitial Cells:
  • Located outside seminiferous tubules.
  • Produce testosterone.
• Testosterone:
  • Crucial for primary male sexual development (phenotypic male characteristics, development of testes and penis).
  • Responsible for male secondary sexual characteristics (hair growth, larger size, bone density).
  • Supports sperm production, sex drive, and bone density maintenance.
• Actin and Inhibin:
  • Recall from the ovary lecture: affect follicle stimulating hormone.
  • Actin stimulates; Inhibin inhibits.

Important Visual References

• Rat Model:
  • Displays the scrotum and testis structure.
  • Epididymis shown but not focus for this section.

Conclusion

• Remember to review photos and other videos for further study.