Question

Explain the source and functions of sex hormones.

Answer 1

The main sex hormones involved in human reproduction are testosterone, oestrogen and progesterone. Their production is regulated by hormones from the pituitary gland, and their levels change at puberty and during the reproductive cycle.

Hormone	Main source	Main functions
Testosterone	It is produced mainly by the Leydig (interstitial) cells of the testes.	It supports sperm production and the development and maintenance of male secondary sex characteristics, such as facial hair, a deeper voice and increased muscle development.
Oestrogen	It is produced mainly by developing ovarian follicles; the corpus luteum and, during pregnancy, the placenta also produce it.	It supports the development of female secondary sex characteristics and helps rebuild and thicken the uterine lining during the menstrual cycle. It also contributes to reproductive development.
Progesterone	It is produced mainly by the corpus luteum after ovulation; during pregnancy, the placenta becomes an important source.	It helps maintain the uterine lining for implantation and pregnancy. It also contributes to changes in the breasts in preparation for lactation.

Together, these hormones regulate reproductive development and help prepare the body for possible fertilisation, implantation and pregnancy.