Menstrual cycles Flashcards Preview

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Flashcards in Menstrual cycles Deck (45):
1

Initiation of pregnancy for the sperm

Sperm must move from the vagina through the uterus and into the fallopian tube. Egg and sperm have to meet within 6-24 hours after ovulation

2

how long after ovulation do the sperm have to meet an egg>?

6-24 hours

3

What must happen to the sperm that allows them to penetrate the zona pellucida surrounding the egg?

capacitation

4

Where does fertilization occur?

upper oviduct

5

survivability (fertilizability) of the ovum?

6-12 hours

6

survivability of the sperm?

1-2 days

7

Sexual interest in women peaks when?

Midcycle (right around the time of ovulation) and just before menstruation

8

volume of ejaculation

1-3 ml, 100 million sperm in each ml

9

Cervical mucus thinning occurs mid cycle and is stimulated by

estrogen

10

motility of the female tract

Prostaglandins in semen, estradiol, oxytocin

11

Highest chance of pregnancy

The day of ovulation or 1-2 days prior. Up to five days prior since thats how long the sperm can survive. Pregnancy chances decrease to zero by one day after ovulation since the egg is only fertilizable for about 6-12 hours

12

At birth, 1 million germ cells

at puberty, 300,000

13

When does menopause start

when all eggs are gone...estrogen falls, FSH and LH rise

14

Cycle

Follicle secretes mainly estrogen (increasing amounts for the first two weeks).
- The estrogen is made by the granulosa cells which make it out of the androgens produced by the thecal cells stimulated by LH The granulosa cells are stimulated by FSH

15

How many follicles develop in each cycle?

only one, this dominany follicle secretes substances that cause the others to regress

16

What makes inhibin and what does inhibin do?

Granulosa cells, it turns off FSH after the follicular phase is over and throughout the luteal phase

17

Cycle starts when

first day of bleeding....period is the start of a cycle not the end

18

Basal body temp rises when

directy after ovulation

19

FSH rises at the end of a cycle and through the period. Why

Because Estrogen, Progesterone, and Inhibin have fallen to allow FSH to rise and begin to stimulate growth of new follicle

20

Estrogen rises throughout the follicular phase why?

When it reaches a certain point it stops being an inhibitory hormone and causes a spike in FSH and LH

21

midcycle LH surge leads to

ovulation

22

BC pills prevent

MIDCYCLE LH SURGE

23

Rise in progesteron around midcycle tells you:

Follicle is changing to corpus luteum

24

Why does Basal body temperature go up?

Progesterone resets the temperature control

25

Endometrial phases during menstrual cycle

- Menstrual phase (5 days)- sloughing off of uterine lining
- Proliferative Phase (11 days)- glands that are lined by secretory cells which secrete things like glucose into the uterine lumen to keep the blastocyst viable
- Secretory phase- persists through teh luminal phase

26

What provides blood to the proliferative phase and secretory phase uterine linings

spiral arteries

27

During the Follicular phase: Hypothalamus secretes

GnRH

28

GnRH tells the gonadotrophs to secrete what?

FSH and LH

29

FSH stimulates what in the ovary?

Granulosa cells

30

Granulosa cells mak what

Estrogen (from the androgens produced by thecal cells) and Inhibin

31

LH stimulates what

Thecal cells

32

Thecal cells produce what

Androgen which is used to make estrogen

33

Inhibin feeds back where

Anterior pituitary and hypothalamus to decrease LH and FSH

34

KNOW CHART IN NOTES

ok

35

FSH does what to Granulosa cells

causes them to proliferate and produce Estradiol

36

Estradiol stimulates more proliferation in granulosa cells

This is positive feedback

37

Ovulation is triggered by

midcycle LH surge

38

During ovulation, the follicular membrane

ruptures after being attacked by proteolytic enzymes

39

Variation in length of a woman's menstrual cycle is caused by

length of the follicular phase, ie, time for dollicle to develop and the ovum be released

40

hCG

keeps the corpus luteum from degenerating

41

Luteal phase highlight

The development of corpus luteum

42

Corpus luteum begins to develop when

a few days before ovulation (see this by spike in progesterone)

43

How long does the CL last

2 weeks but it is degenerating in the last 5 days. This is called luteolysis

44

CL secretes

estrogen, lots of progesterone, 17 hydroxyprogesterone and inhibin

45

17 hydroxy does what>

who cares