Which glands in the male reproductive system secrete fluid rich in fructose?

The male reproductive system includes several glands that contribute to the formation of semen, and the seminal vesicles play a crucial role in this process. These glands secrete a fluid that is rich in fructose, which is a vital energy source for sperm. Fructose is important because sperm require energy to swim through the female reproductive tract and reach the egg for fertilization. The seminal vesicles produce approximately 60-70% of the total volume of semen, and their secretion not only nourishes the sperm but also helps to enhance their motility and viability.

The other glands mentioned have different functions. The prostate gland contributes a slightly alkaline fluid that helps to neutralize the acidity of the female vaginal tract, which is important for sperm survival. The bulbourethral glands secrete a pre-ejaculatory fluid that helps lubricate the urethra and neutralizes any acidity in the urethra prior to ejaculation. The vas deferens is primarily a duct that transports sperm from the epididymis to the ejaculatory duct and does not secrete fluid. Therefore, the seminal vesicles are specifically responsible for secreting fluid rich in fructose, making them the correct choice in this context.