See testes

Testosterone is the main male sex hormone that is produced in the testes. One of its functions is to stimulate (“wake up”) the development of the male internal genital structures in the fetus. Testosterone is converted in the external genital tissues to a stronger hormone, dihydrotestosterone, to cause male development of the external genitals. It is also produced during a brief period in early infancy, then again at puberty, when it stimulates enlargement of the penis, deepening of the voice and other typical features of male secondary sex characteristics. During adult life it is responsible for maintenance of male-type body structure and is involved in sex drive (libido) and sexual function.

Turner Syndrome occurs when an individual has a karyotype of 45,X (or 45,XO). Girls and women with Turner Syndrome typically have ovaries that don't function well, resulting in a lack of menses, and infertility.

Urethral folds are present in all embryos early in development. The urethral folds typically develop into the labia minora in females and the urethra and the shaft of the penis in males.

The uterus is an organ that typically connects with the vagina in females. It is located in the pelvic region and is where babies develop, and is also the source of menstrual flow.

Wolffian ducts are present in all embryos in early development. In males, the Wolffian ducts typically develop into the vas deferens, the epididymis, and the seminal vesicles. The vas deferens is the passageway that carries sperm from the epididymis to the ejaculatory duct. The epididymis is an organ located on the testes that has passageways (ducts) that carry sperm from the testes to the vas deferens. The seminal vesicles are glands that produce the fluid component of semen. In females, the Wolffian ducts typically regress (disappear) before birth.

XY gonadal dysgenesis, occurs when no functional gonads are present, and results in female anatomy (other than gonads) and external appearance Synonyms: Swyer syndrome