Steps of ovarian cycle

Question 1

Step 1

Answer 1

beginning of mestruation; low levels of steroid hormones
- cause release of GnRH because there is no neg. feedback

Question 2

Step 2

Answer 2

Secretion of GnRH and gonadotropins

Question 3

Step 3

Answer 3

Growth of the follicle (due to FSH); increase in estrogen
- thecal cells secrete androgen- FSH stimulates aromatase- aromatase converts androgen to estrogen

Question 4

Step 4

Answer 4

Outgrow of Graafian follicle
- shuts down FSH and sends paracrine signal to other follicles
- also releases so much estrogen

Question 5

Step 5

Answer 5

Estrogen released from Graafian follicle causes positive feedback and LH surges
- oocyte burst out of ovary and remaining follicular cells have receptors for LH

Question 6

Step 6

Answer 6

LH stimulates corpus luteum
- no more growing follicle

Question 7

Step 7

Answer 7

Estrogen goes from above threshold to below and goes from positive to negative feedback; LH and FSH decrease
Regression of Corpus luteum

Question 8

Step 8

Answer 8

Corpus albicans remains