Secretions from the __ gland serves as a lubricant for the sperms to move through the penis.
Bulbo-urethral glands
The seminal vesicles, the prostate and the bulbourethral glands all contribute to the production of semen. The seminal vesicles provide nutrients and mobility to the immobile sperm, while the bulbourethral glands produce secretions that serve as a lubricant for the sperms.