Overview
This lecture covers the key structures and functions of the male reproductive system, emphasizing sperm production, storage, and the role of different glands.
Structure and Function of Male Reproductive System
- The male reproductive system shares the urethra with the urinary system (called the urogenital system).
- The bladder is connected to the penis through the urethra, which carries both urine and semen.
- The testes are the main reproductive organs, housed in the scrotum outside the body for temperature regulation.
Testes and Sperm Production
- The scrotum protects the testes and regulates temperature, keeping them about 2°C cooler than body temperature for sperm production.
- The testes are the site of spermatogenesis (sperm production) and testosterone synthesis.
- Seminiferous tubules inside the testes are where sperm cells are formed from diploid to haploid cells under testosterone influence.
- Sperm mature and develop tails in the epididymis, where they are stored until ejaculation.
Sperm Transport Pathway
- During ejaculation, sperm travel from the epididymis through the vas deferens (also called sperm duct), a muscle-lined tube.
- The vas deferens joins the urethra, where sperm mixes with gland secretions to form semen.
Glands and Secretions
- The prostate gland (one) produces nutrient-rich secretions for sperm energy.
- The seminal vesicles (two) secrete fluids that neutralize vaginal acidity, aiding sperm survival.
- Cowper's (Bulbourethral) glands (two) produce thick, alkaline mucus to enhance sperm motility and neutralize acid in the urethra.
Urethra and Penis
- The urethra transports both urine and semen and starts from the bladder, continuing through the penis.
- The penis contains erectile tissue and functions to deliver semen into the vagina for fertilization.
Key Terms & Definitions
- Scrotum — external sac protecting and regulating the temperature of the testes.
- Testes — organs that produce sperm and testosterone.
- Seminiferous tubules — tiny tubes inside testes where sperm are formed.
- Spermatogenesis — process of forming haploid sperm cells from diploid cells.
- Epididymis — structure where sperm mature and are stored.
- Vas deferens — muscular tube carrying sperm from epididymis to urethra.
- Prostate gland — adds nutrients to semen for sperm energy.
- Seminal vesicle — secretes fluid to neutralize vaginal pH.
- Cowper’s gland — produces mucus aiding sperm movement and neutralizing urethra acidity.
- Urethra — tube carrying urine and semen through the penis.
- Penis — organ delivering semen to the vagina during reproduction.
- Semen — mixture of sperm and gland secretions.
Action Items / Next Steps
- Review the exam guideline definition of spermatogenesis.
- Make flashcards for all key terms listed.
- Watch the linked spermatogenesis video for further understanding.