Vagina
A tubular passageway in the female connecting the external sex organs with the cervix and uterus. 

Varicocele
A varicocele vein of the testicles, sometimes a cause of male infertility.

Vas deferens
A pair of thick-walled tubes about 45 cm long in the male that lead from the epididymis to the ejaculatory duct in the prostate. During ejaculation, the ducts make wavelike contractions to propel sperm forward.

Vas deferens
The tubes that conduct sperm and testicular fluid to the ejaculatory ducts.

Vasectomy
Surgical sterilization of a man by interrupting both vas deferens. 

Vasectomy reversal
Surgical repair of a previous vasectomy for a man who wants to regain his fertility. 

Venereal disease
See Sexually Transmitted Diseases (STD). 

Virus
A microscopic infectious organism that reproduces inside living cells.