What substance do the bulbourethral glands secrete?

The bulbourethral glands, also known as Cowper's glands, play a specialized role in male reproductive physiology by secreting an alkaline mucous-like fluid. This secretion serves several important functions during sexual arousal and ejaculation.

Firstly, the alkaline nature of the fluid helps to neutralize any acidity in the urethra, which can be detrimental to sperm viability. This creates a more favorable environment for sperm as they travel through the male and female reproductive tracts. Additionally, the mucous-like consistency of the secretion provides lubrication, which aids in the process of ejaculation, facilitating the passage of sperm.

In contrast, testosterone is produced by the testes and is crucial for the development of male secondary sex characteristics but is not a product of the bulbourethral glands. Prostate fluid is secreted by the prostate gland and contributes to seminal fluid, but it is distinct from the fluid secreted by the bulbourethral glands. Seminal fluid is the collective result of secretions from multiple glands, including the seminal vesicles and prostate, rather than a specific secretion from the bulbourethral glands alone. Thus, the secretion of an alkaline mucous-like fluid is the defining characteristic of the function of the bulbourethral glands.