Normal Menstrual Cycle

What does the hypothalamus release?

gonadotropin-releasing hormone

What is the purpose of gonadotropin-releasing hormone?

regulate the release of hormones by the anterior pituitary gland

What hormones does the pituitary gland release?

FSH and LH

What is the purpose of FSH?

stimulates ovaries to develop follicles and maturation of the dominant follicle

What hormone do the ovarian follicles produce?

estrogen

When is there a peak in estrogen?

as the dominant follicle reaches maturity

What is the purpose of LH?

stimulates the rupture of the dominant follicle—>causes ovulation

What is the name of the ruptured dominant follicle?

corpus luteum

What does the corpus luteum secrete?

progesterone and small amounts of estrogen

What is the role of estrogen in regards to the endometrium?

thicken the endometrium

What is the role of progesterone in regards to the endometrium?

maintain the endometrium

What happens during the follicular phase of the ovary?

• FSH stimulates follicle development & follicle matures until ovulation around day 14

• follicles—>release estrogen

What happens during the menstrual phase of the endometrium?

shedding of the endometrium

What happens during the early proliferative phase of the endometrium?

• immediately following menses

• endo is thin and echogenic (up to 4 mm)

What happens during the late proliferative phase of the endometrium?

• endometrium reaches 6-10 mm and appears as 3 line sign

• basal layer→echogenic rim

• functional layer—>hypoechoic inner layer

What happens during ovulation?

• around day 14, LH surges and causes rupture of the dominant follicle

• ovum released

• free fluid may settle in posterior CDS

What happens during the luteal phase of the ovary/the secretary phase of the endo?

• the graafian follicle becomes corpus luteum

• produces progesterone to maintain endo thickness

• endo is thick and echogenic (7-16 mm)