NURSING 101Chapter 23: Structure and Function of the Reproductive Systems

The initial reproductive structures of the male and female embryos appear the same until which week of gestation? a. Third c. Twentieth b. Eighth d. Thirtieth ANS: B Between 6 and 7 weeksÕ gestation, the male embryo differentiates under the influence of testes-determining factor (TDF). In the absence of testosterone, a loss of the wolffian system occurs and the two gonads develop into ovaries at 6 to 8 weeksÕ gestation. PTS: 1 REF: Page 769 2. The absence of which major hormone is a determinant of sexual differentiation (wolffian system) in utero? a. Estrogen c. Growth hormone b. Progesterone d. Testosterone ANS: D In the absence of testosterone, a loss of the wolffian system occurs and the two gonads develop into ovaries at 6 to 8 weeksÕ gestation. Between 6 and 7 weeksÕ gestation, the male embryo differentiates under the influence of TDF. The presence of estrogen is a determinating factor. None of the other options function as a major determinant to sexual differentiation in utero. PTS: 1 REF: Page 769 3. Which gland produces the associated hormones that are found in high levels in a female fetus? a. Posterior pituitary excretes gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH). b. Hypothalamus excretes luteinizing hormone (LH) and gonadotropin-releasing hormone (GnRH). c. Anterior pituitaryfollicle-stimulating hormone (FSH) and luteinizing hormone (LH). d. Hypothalamus excretes gonadotropin-releasing hormone (GnRH) and follicle-stimulating hormone (FSH). ANS: C