Give an example to show how hormones can influence visible changes in your body. (AS1)

An example to show how hormones can influence visible changes in our body is the functioning of gonads. Gonads are the sex glands: ovaries and testes. They produce ova and sperms but also secrete hormones. The various gonads are :

Ovaries - They produce estrogens, progesterone, relaxing and inhibin. Estrogens are secreted by Graafian follicles. Estradiol is the principal feminizing hormone. It stimulates the development of female secondary sex characteristics during puberty such as development and enlargement of breasts, broadening of the pelvic region, accumulation of fat in the lower part of the body, etc.and maintains them through the reproductive years of adult life.

Progesterone is secreted by corpus luteum. It stimulates further development of the uterine epithelium and mammary glands. Relaxin is secreted by corpus luteum only during the later stages of pregnancy and helps to soften ligaments especially those that hold the pubic symphysis. It affects women foot ligaments, she may experience an increase in shoe size following pregnancy.

Testes - Testes secrete male sex hormones called androgens. The main one is testosterone. It stimulates the growth & development of male secondary sex organs like seminal vesicles, prostate & penis. This hormone stimulates the development of male secondary sexual characteristics like the beard, mustache, and low pitch male voice in man.