Lecture Notes: Male Reproductive System

Overview

• Focus on sperm delivery from the testes to outside the body.
• Discusses structure and function of associated ducts and glands.

Pathway of Sperm

1. Testes
   • Sperm production.
   • Rete Testis: Initial meshwork for sperm transport.
2. Efferent Ductules
   • Lined with ciliated epithelium.
   • Move sperm to the epididymis.
3. Epididymis
   • Stores and matures sperm.
   • Comprised of head, body, and tail.
4. Ductus Deferens (aka Vas Deferens)
   • Transports sperm from epididymis.
   • Part of the spermatic cord, passes through inguinal canal.
5. Ejaculatory Duct
   • Formed by union of ductus deferens and seminal vesicle.
   • Transports sperm into urethra.
6. Urethra
   • Divided into prostatic, membranous, and spongy segments.
   • Transports semen outside the body.

Semen Composition

• Seminal Fluid: Alkaline to neutralize vaginal acidity.
• Nutritional Content: Fructose provides energy for sperm.
• Glandular Contributions:
  • Seminal Vesicles: Alkaline fluid with fructose and prostaglandins.
  • Prostate Gland: Milky fluid with citric acid, seminal plasmin, PSA.
  • Bulbourethral Glands: Pre-ejaculate fluid lubricates and neutralizes urethra.

Sperm Production and Ejaculation

• Sperm Count: 200 to 500 million sperm per ejaculate.
• Role of Semen: Nutrients and protection for sperm.
• Sperm Transport Time: Approx. two weeks from production to ejaculation.

Health Considerations

• Benign Prostatic Hyperplasia (BPH):
  • Non-cancerous enlargement of prostate.
  • Causes urinary issues due to urethra compression.
  • Treatments include medication like finasteride or surgery.
• Prostate Cancer:
  • Common in men over 50.
  • Detected via PSA test or digital rectal exam.
  • Treatments include radiation or surgery.

Male Sexual Response

1. Erection:
   • Involves filling of erectile bodies.
   • Mediated by parasympathetic innervation and nitric oxide.
2. Ejaculation:
   • Contraction of ductus deferens.
   • Combination of sperm with glandular fluids to form semen.
   • Sympathetic stimulation closes urethral sphincter.

Summary

• Comprehensive overview of the male reproductive system.
• Covers anatomy, physiology, and common medical issues.