What anatomical structures swell during the 7th week of gestation?

During the 7th week of gestation, the anatomical structures known as the genitalia experience significant development and differentiation. This period marks the transition from the undifferentiated state of the embryonic gonads toward their identifiable male or female forms, influenced by genetic and hormonal factors.

In males, the presence of the Y chromosome triggers the development of testes, which begin to produce testosterone, leading to the formation of male genital structures. In females, the absence of certain male-determining hormones allows the development of female genitalia. The pronounced alteration in the morphology of these structures is critical for the subsequent development of sex-specific characteristics.

This is a crucial period where external and internal reproductive organs begin to resemble those of the eventual male or female phenotype, making the genitalia's growth and differentiation a key feature of early fetal development. Understanding this stage is fundamental for grasping human sexual development and the factors that influence it.