1. If an adult male were castrated (testes were removed), what would happen to the levels of GnRH, FSH, LH, and testosterone in his blood? What effect would these hormonal changes have on his sex characteristics and sexual behavior?

2. If the ovaries are removed from a 20-year-old woman, what happens to the levels of GnRH, FSH, LH, estrogen, and progesterone in her blood? What side effects would these hormonal changes have on her sex characteristics and sexual behavior?

1. If an adult male were castrated (testes were removed), what would happen to the levels of GnRH, FSH, LH, and testosterone in his blood? What effect would these hormonal changes have on his sex characteristics and sexual behavior? Removing the testes would eliminate the major source of

testosterone. Blood levels of testosterone would therefore decrease. Because testosterone has a negative-feedback effect on the hypothalamus and pituitary gland, GnRH, FSH, and LH secretion would increase, and the blood levels of these hormones would increase. An adult male’s primary and secondary sex characteristics are already developed; however, removal of the testes would eliminate sperm production. Also, the lack of testosterone would cause a decrease in sex drive and muscular strength.

2. If the ovaries are removed from a 20-year-old woman, what happens to the levels of GnRH, FSH, LH, estrogen, and progesterone in her blood? What side effects would these hormonal changes have on her sex characteristics and sexual behavior?

The removal of the ovaries from a 20-yearold woman eliminates the major site of estrogen and progesterone production, thereby causing an increase in GnRH, FSH, and LH levels due to lack of negative feedback. We would expect to see the symptoms of menopause, such as cessation of menstruation and reduction in the size of the uterus, vagina, and breasts. A temporary reduction in sex drive may also occur.