This chapter explains the relationship between human reproduction and human development and describes the functions of the male and female reproductive systems. Reproduction is the process by which organisms produce offspring to continue the species. In both sexes, the reproductive system consists of gonads, reproductive ducts, glands, and external genitalia. The external genitalia of the male are the penis and scrotum. The male gonads are the paired testes located outside of the abdominal cavity in the scrotum. The chapter provides the pathway of spermatozoa from their origin in the seminiferous tubules to the urogenital opening on the glans penis. Beginning with the seminiferous tubules in the testes, there is a continuous passageway for the sperm to the urogenital opening on the tip of the penis. The chapter describes the pathway of the egg from its origin in the ovary to the vaginal opening and the menstrual cycle.