Question

List the hormones secreted by ovary.

Answer 1

The ovaries secrete two types of female sex hormones called the estrogens and the progestins.
Estrogens

• In Non-pregnant females, they are predominantly secreted by the ovaries. However, during pregnancy, the placenta secretes a lot of estrogens.
• The three types of estrogens are; ββ-estradiol, estrone and estriol.
• The most active and the principal estrogen produced by the ovaries is the ββ-estradiol.
• They play an important role in the growth and development of ovarian follicles and breast
• They are responsible for the development of secondary sexual characteristics (e.g. high pitch voice)
• They inhibit osteoclastic activity and stimulate bone growth. Osteoporosis in menopausal women is because of reduced estrogen levels.
• They also influence the texture of the skin and female sexual behaviour

Progestins (Progesterone)

• The progestins are secreted by the corpus luteum, a structure that is formed from the ruptured follicle (after ovulation/ later half of ovarian cycle).
• Most important progestin is the progesterone. Small amounts of 17-αα-hydroxyprogesterone is also secreted along with progesterone.
• Placenta also secretes large amounts of progesterone during pregnancy.
• The progestins mainly have 2 functions; prepare the uterus for pregnancy and prepare breasts for lactation.
• Progesterone acts on mammary glands and stimulates the formation of milk storing sacs called alveoli and milk secretion.