Final answer:
Semen is formed by the prostate gland, seminal vesicles, and bulbourethral glands, which contribute a slightly acidic milky fluid, 70% of seminal fluid, and thick alkaline mucus, respectively.
Step-by-step explanation:
The structures contributing to the formation of semen are:
- Prostate Gland: This gland secretes a slightly acidic, milky fluid that is a significant component of semen.
- Seminal Vesicles: Paired glands that produce about 70% of seminal fluid, which is alkaline and contains fructose and prostaglandins vital for sperm motility and viability.
- Bulbourethral Glands: These glands release a thick, clear, alkaline mucus that serves as a lubricant and helps neutralize the acidity of any residual urine in the urethra.