In the absence of testicular secretions, the female genitalia are formed. The prostate gland derives from the urogenital sinus, and the other embryonic structures differentiate into the external genitalia. The structures are masculinized by secretions of the testes: In the developing embryo if the testes are developed, it will produce and secrete male sex hormones during late embryonic development and cause the secondary sex organs of the male to develop. Genetic sex determines whether the gonads will be testes or ovaries. A sperm cell carrying a Y chromosome results in an XY combination, and a male child will develop. If this sperm cell contains an X chromosome it will coincide with the X chromosome of the ovum and a female child will develop. Sexual identity is determined at fertilization when the genetic sex of the zygote has been initialized by a sperm cell containing either an X or Y chromosome. Sexual determination Human karyotype, showing 22 homologous autosomal chromosome pairs, both the female (XX) and male (XY) versions of the two sex chromosomes, as well as the mitochondrial genome (at bottom left). Their development can also be described together as the development of the urinary and reproductive organs. The development of the male reproductive system coincides with the urinary system. It is a part of the stages of sexual differentiation.

It begins with a single fertilized egg and culminates 38 weeks later with the birth of a male child. The embryonic and prenatal development of the male reproductive system is the process whereby the reproductive organs grow, mature and are established. Bulbourethral glands: add fluid to semen during ejaculation ( pre-ejaculate).Prostate gland: a gland located below the bladder that produces seminal fluid and helps regulate urine flow.

Seminal vesicles: two glands behind the bladder that secrete many of the semen's components.

Three accessory glands provide fluids that lubricate the duct system and nourish the sperm cells.

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