The reproductive system is a collection of internal and external organs in both males and females that work together for the purpose of procreating, according to the Cleveland Clinic. Due to its vital role in the survival of the species, many scientists argue that the reproductive system is among the most important systems in the entire body. The male reproductive system consists of two major parts: the testes, where sperm are produced, and the penis. The penis and urethra belong to both the urinary and reproductive systems in males. The testes are carried in an external pouch known as the scrotum, where they normally remain slightly cooler than body temperature to facilitate sperm production. The external structures of the female reproductive system include the clitoris, labia minora, labia majora and Bartholin's glands, according to the Cleveland Clinic. The major internal organs of the female reproductive system include the vagina and uterus which act as the receptacle for semen and the ovaries, which produce the female's ova. The vagina is attached to the uterus through the cervix, while the fallopian tubes connect the uterus to the ovaries. In response to hormonal changes, one ovum, or egg or more in the case of multiple births is released and sent down the fallopian tube during ovulation. If not fertilized, this egg is eliminated during menstruation.