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Flashcards in Hormonal Cycle Deck (54)
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1

Ages of menarche and menopause

12.5
51

2

At birth females have 1 million primordial follicles. They oocytes are arrested in _______

prophase of the first meiotic division until menarche

3

The hypothalamus secretes ________ from the _________ in a ________ manner.

GnRH from the arcuate nucleus in a pulsatile manner (every 70-90 minutes)

4

GnRH stimulates the ________ to release ________

anterior pituitary to release FHS and LH (gonadotropins)

5

TSH acts at

thyroid gland

released from ant pit

6

ACTH acts at

adrenal cortex

released from ant pit

7

TSH and LH act at

testes and ovaries

released from ant pit

8

GH acts at

entire body

released from ant pit

9

PRL (prolactin) acts at

mammary glands

released from ant pit

10

endorphins act on

pain receptors in brain

released from ant pit

11

LH stimulates ______, which causes _________

1. LH stimulates theca cells of ovary to produce androgens
2. Androgens to to granulosa cell of ovary and are converted to estrogen by aromatase

12

FSH stimulates _______ which causes ________

1. FSH stimulates granulosa cells to convert androgens (coming from the thecal cells) to estrogen by aromatase during the follicular phase of the menstrual cycle

13

Estradiol (estrogen) has a negative feedback on ______ and a positive feedback on ______

negative fb on GnRH and FSH/LH most of the cycle, but a positive fb on GnRH/FSH/LH for days 12-14 (high estrogen levels during this time)

14

So basically granulosa cells of ovary produce ______ and theca cells produce _______

estradiol
androgen

15

Estrogen provides _________ to hypothalamus and anterior pituitary for most of the cycle, but ________ for days 12-14

negative fb for most

positive fb for days 12-14
(the positive fb of estrogen is mostly acting on LH)

16

In order for FSH and LH to be released, you need ________

a PULSATILE release of GnRH

17

LH acts on 2 places in the ovary (and why)

1. growing follicle (for ovulation and to produce estrogen, this mid-cycle increase of estrogen will stimulate more LH secretion, positive FB)

2. corpus luteum (which secretes progesterone and estrogen after ovulation to inhibit FSH and LH secretion)

18

Phases of menstrual cycle

follicular phase, ovulation, luteal phase

19

Day 1 of follicular phase:

-First day of bleeding
-progesterone withdrawal is happening (causes period bleeding)
-Prostaglandins are released--> causes contractions of uterus
--> ischemic pain (cramping)
-hormones are all at their LOWEST points on day 1
-this causes at DECREASE in the negative feedback, resulting in FSH production

20

FSH production on day 1 of follicular phase causes

-new follicles to mature
-dominant follicle to be selected
-granulosa cells increase and secrete estradiol

21

Follicular phase- Estradiol acts at the LH receptors on

theca cells, cause androgen secretion, which are converted to more estradiol by aromatase

22

Follicular phase- Rising estradiol causes an INCREASE in negative feedback at the hypothalamus, which will _______

decrease FSH and increase LH

23

Determining Dominant Follicle- FSH binds to receptors on the granulosa cells, causing ______

proliferation of cells --> more binding of FSH --> more estradiol produced

24

Determining Dominant Follicle- The follicle with the ________ becomes the dominant follicle, and then OVULATION HAPPENS!

greatest # of granolas cells

(this is the best follicle- has the most estrogen production, greatest number of granulosa cells)

25

The ONLY FOLLICLE that ovulates is _________

the dominant follicle

26

Ovulation- estradiol produced causes

a positive feedback at hypothalamus causing an increase in LH

27

_________ happens around days 11-13 of cycle

LH Surge

28

Ovulation starts ______ AFTER the LH surge

30-36 hours

-so ovulation happens around day 14 of cycle

29

During ovulation what physically happen to oocyte?

oocyte is expelled from follicle into fallopian tube, and the follicle becomes the corpus luteum (follicle without egg in it anymore is corpus luteum)

30

Luteal phase of menstrual cycle is ________ dominant

progesterone dominant (bc the progesterone is coming from the corpus luteum)