Hormonal control of reproductive system

[***] Menstrual cycle control centers

hypothalamus and anterior pituitary gland

[***] Follicle stimulating hormone (FSH) production site

anterior pituitary gland

[***] Follicle stimulating hormone (FSH) primary functions

stimulates follicles to develop in ovaries; stimulates oestrogen production from developing follicle

[***] Luteinising hormone (LH) production site

anterior pituitary gland

[***] Luteinising hormone (LH) primary functions

stimulates ovulation; stimulates corpus luteum development for oestrogen and progesterone production

[***] Oestrogen production site during the menstrual cycle

developing follicle and yellow body (corpus luteum) in ovaries

[***] Oestrogen primary functions in the menstrual cycle

stimulates uterine lining to thicken; stimulates pituitary gland to produce LH; initially inhibits FSH secretion

[***] Progesterone production site during the menstrual cycle

yellow body (corpus luteum) in ovaries

[***] Progesterone primary functions in the menstrual cycle

maintains thickness of uterine lining; inhibits FSH and LH secretions

[***] Menstrual cycle days 1-13 hormonal changes

FSH increases and stimulates follicle development; developing follicle secretes oestrogen

[***] Menstrual cycle days 1-13 oestrogen feedback

exerts negative feedback to inhibit FSH secretion from the pituitary to prevent another follicle from developing

[***] Menstrual cycle ovulation (Day 14) trigger

sharp increase in LH stimulates ovulation and causes the follicle to burst releasing an ovum into the oviduct

[***] Menstrual cycle pre-ovulation oestrogen surge

high oestrogen level stimulates secretion of FSH and LH via positive feedback

[***] Menstrual cycle days 15-28 corpus luteum formation

LH stimulates the ruptured follicle to develop into a yellow body (corpus luteum)

[***] Menstrual cycle days 15-28 endometrial changes

high levels of oestrogen and progesterone cause thickening and vascularisation of the uterine lining

[***] Menstrual cycle days 15-28 hormonal feedback

high level of progesterone inhibits FSH and LH secretion from the pituitary via negative feedback

[***] Menstrual cycle absence of fertilization

corpus luteum breaks down due to lower LH levels causing oestrogen and progesterone to decrease quickly

[***] Menstrual cycle menstruation trigger

quick decrease in oestrogen and progesterone leads to the breakdown of the thickened uterine lining

[**] Combined contraceptives composition

combination of synthetic oestrogen and progesterone

[**] Combined contraceptives mechanism

inhibit FSH and LH secretion from the pituitary; prevent follicle development and ovulation

[**] Combined contraceptives forms

combined oral contraceptive pills (COCP); vaginal ring; adhesive skin patches; injections

[**] Progesterone-only contraceptives clinical indication

used for breastfeeding women who cannot take oestrogen-based pills

[**] Progesterone-only contraceptives mechanism

inhibits ovulation; causes thickening of cervical mucus to prevent implantation; inhibits FSH secretion

[**] Progesterone-only contraceptives forms

oral contraceptive pills (minipills); injections; skin implants

[**] Infertility definition

inability to achieve pregnancy after a year of regular normal sexual intercourse without contraceptives

[**] Infertility common causes

blockage of oviducts; low sperm count; abnormal appearance of sperm; low mobility of sperm

[**] Infertility treatment using exogenous hormones

drugs containing FSH and LH to treat failure of follicle development or ovulation; oestrogen and progesterone to thicken uterine lining

[**] Infertility treatment using anti-oestrogen drugs

chemicals that inhibit oestrogen secretion to reduce inhibition of FSH secretion; stimulates follicle development and increases chance of multiple births