Final answer:
Structures of the male reproductive system, such as the seminal vesicles, prostate gland, and the bulbourethral glands, enhance sperm motility by producing fluids that create an alkaline environment, provide energy, and neutralize acidity. Leydig and Sertoli cells play supporting roles in developing sperm and hormone secretion but do not directly enhance motility. Sperms gain the ability to move in the epididymis.
Step-by-step explanation:
Structures of the male reproductive system enhance the motility of sperm through various means. The seminal vesicles produce an alkaline fluid that helps reverse the acidity of the vaginal environment, which is crucial since sperm are only motile in an alkaline environment. Semen also contains nutrients, sugars like fructose that provide energy for sperm, and other compounds that support motility and viability of sperm.
The prostate gland contributes to this by secreting seminal fluid, which contains substances that aid in activating sperm flagella and increasing sperm motility. Similarly, the bulbourethral glands add fluid to semen that lubricates the urethra and neutralizes traces of acidic urine, facilitating sperm motility. Leydig cells contribute indirectly by secreting testosterone, which is critical for the overall development and functioning of the male reproductive system, though not directly enhancing sperm motility.
Sertoli cells, while involved in nourishing and protecting developing sperm, do not directly increase motility but are essential in the overall support of spermatogenesis. Maturation in the epididymis is the phase where non-motile sperms gain motility after being secreted by the Sertoli cells into the testicular fluid.