Module 8: Anatomy of the Male Reproductive System

Overview

• Objective: Understand the basic gross anatomy of the male reproductive system.
• Structure: Four main parts:
  1. Male gonads (testis)
  2. Ducts transporting gametes
  3. Copulatory organ (penis)
  4. Accessory sex glands
• Goal: Identify organs and trace the path of spermatozoa from testis to penis.

Male Reproductive System

Functions

• Perpetuation of life through reproduction.
• Production of sex-specific gametes (spermatozoa in males).
• Accessory sex glands nourish spermatozoa.
• Structures enable fertilization.

Main Components

1. Scrotum

   • Pouch of skin containing testes.
   • Lies between thighs; left further caudal.
   • Divided by scrotal septum.
   • Layers: skin, tonica dartos (smooth muscle), spermatic fascia.
   • Thermoregulation through cremaster muscle.

2. Testis

   • Male gonad producing spermatogonia and testosterone.
   • Descent guided by gubernaculum.
   • Structure:
     • Connective Tissue: Tunica albuginea, septa, mediastinum.
     • Parenchyma: Seminiferous tubules, rete testis, efferent ducts.

3. Epididymis

   • Attached to testis; parts include head, body, and tail.
   • Consists of epididymal duct leading to ductus deferens.

4. Duct System

   • Order: Seminiferous tubules → Rete testis → Efferent duct → Epididymal duct → Deferent duct → Urethra.

5. Spermatic Cord

   • Composed of vas deferens, testicular artery/veins/nerves, lymphatics.
   • Contains pampiniform plexus for thermoregulation.

6. Accessory Sex Glands

   • Provide liquid to ejaculate; include prostate, bulbourethral, vesicular, and ampullary glands.
   • Prostate Gland: Envelopes proximal urethra, function not fully understood.

7. Penis

   • Copulatory organ, passage for semen and urine.
   • Types: Musculocavernous (humans, dogs) and fibroelastic (ruminants).
   • Structure: Corpus cavernosum (dorsal), corpus spongiosum (ventral).
   • Other features: Prepuce, os penis, bulbous glandis.

Key Anatomical Features

• Thermoregulation: Cremaster muscle and pampiniform plexus.
• Prostate: Implications for urination in cases of tumor.

Conclusion

• Understanding of male reproductive anatomy essential for tracing spermatozoa path and understanding reproductive processes.