Pregnancy

Question 1

How long does the ovarian cycle last for?

Answer 1

~28 days

Question 2

What are the two phases of the ovarian cycle?

Answer 2

Follicular phase

Luteal phase

Question 3

When does menstruation occur?

Answer 3

In the first 3-4 days of the ovarian cycle

Question 4

How long does the follicular phase last for?

Answer 4

Around 16 days

Question 5

How long does the luteal phase last for?

Answer 5

Around 12 days

Question 6

When does ovulation occur?

Answer 6

Around day 16

Question 7

What happens in the follicular phase?

Answer 7

The egg maturates

Question 8

What hormone does the egg secrete?

Answer 8

Oestogen (oestradiol)

Question 9

What happens during the luteal phase?

Answer 9

The egg develops into the corpus luteum

Question 10

What does the corpus luteum produce?

Answer 10

Progesterone

Oestrogen

Question 11

What is the major hormone regulating the ovarian cycle?

Answer 11

Luteinising hormone

Question 12

When is LH highest?

Answer 12

Between days 12 and 16.

Question 13

What happens if fertilization does not occur?

Answer 13

The corpus luteum is lost during menstration

Question 14

What happens if fertilization occurs?

Answer 14

Corpus luteum grows and continues to produce progesterone and oestrogen thus inhibiting further ovulation

Question 15

What hormone is secreted when the corpus luteum implants?

Answer 15

Human Chorionic Gonadotropin (hCG)

Question 16

What hormone is used for pregnancy tests?

Answer 16

Human Chorionic Gonadotropin (hCG)

Question 17

What hormones does the placenta secrete?

Answer 17

Human placental lactogen (hPL)
Placental progesterone
Placental oestrogens

Question 18

What are the six key reproductive hormones?

Answer 18

GnRH
LH
FSH
Oestrogen
Progesterone
Testosterone

Question 19

What does GnRH do?

Answer 19

Stim LH and FSH release

Question 20

How is GnRH released?

Answer 20

Pulsatile manner

Question 21

How do the pulses of GnRH differ between males and females?

Answer 21

Males- constant

Females- Decrease from 1-2x hour in follicular phase to every 4h during luteal

Question 22

What does high frequency pulses of GnRH do?

Answer 22

Stim LH release

Question 23

What does low frequency pulses of GnRH do?

Answer 23

Stim FSH release

Question 24

What happens to GnRH pulses during puberty?

Answer 24

Increase

Question 25

What regulates GnRH release?

Answer 25

Oestrogen | Progesterone

Question 26

What effect does oestrogen have of GnRH release?

Answer 26

Low dose- inhibits | High dose- stims

Question 27

What effect does progesterone have of GnRH release?

Answer 27

Inhibits it

Question 28

Can GnRH neurons sense progesterone and oestrogen?

Answer 28

No therefore need interneurons

Question 29

What does FSH do in males and females?

Answer 29

Males- Stim spermatogenesis | Females- Stim growth of ovarian follicles

Question 30

What does LH do in males and females?

Answer 30

Males- Secrete testosterone from testes | Females- Ovulation and progesterone production

Question 31

What does progesterone do?

Answer 31

Maintain pregnancy- lit 'Pro' 'Gestation'

Question 32

Describe how FSH changes during menstration

Answer 32

Slight rise during follicular phase to stim ovarian follicle growth. Increasing oestrogen from follicles inhibits GnRH/FSH release. Oestrogen continues to rise leading to spike of FSH. FSH levels fall during luteal phase

Question 33

How do LH change during menstruation?

Answer 33

Remain low through most of follicular but spike when lots of oestrogen is released then drop again in luteal phase due to increased progesterone production

Question 34

When does the period start?

Answer 34

1st day of menstrual bleeding

Question 35

What is a follicle?

Answer 35

Oocyte (egg) surrounded by follicular cells

Question 36

What happens to the follicle during the follicular phase?

Answer 36

Follicular cells multiply

Question 37

What hormones are responsible for follicular growth?

Answer 37

LH and FSH

Question 38

What two kinds of cells are involved in follicular growth?

Answer 38

Theca cells | Granulosa cells

Question 39

What hormone acts on theca cells?

Answer 39

LH

Question 40

What do theca cells do?

Answer 40

Convert cholesterol to androgen

Question 41

What hormone acts on granulosa cells?

Answer 41

FSH

Question 42

What do granulosa cells do?

Answer 42

Convert androgen to oestrogen

Question 43

What enzyme helps convert androgen to oestrogen in the granulosa cell?

Answer 43

Aromatase

Question 44

What happens in polycystic ovary disease?

Answer 44

Get problem with FSH/ granulosa cell therefore can't convert androgens

Question 45

How is an egg selected for secretion?

Answer 45

All follicles grow the whole time and if one is ready when FSH is high then it gets selected.

Question 46

What is the dominant follicle?

Answer 46

Several follicles will be ready at a time for selection but the one that is most resistant to low FSH levels will be selected as the dominant one

Question 47

Which hormone regulates the formation of the corpus luteum?

Answer 47

LH

Question 48

What happens to the granulosa and theca cells during the luteal phase?

Answer 48

Become luteal cells

Question 49

Why is the corpus luteum yellow?

Answer 49

Because it's full of cholesterol to produce progesterone

Question 50

What effects do oestrogens have?

Answer 50

Increase thickness of vaginal wall Regulate LH surge Reduce vaginal pH by increasing lactic acid Decrease viscosity of cervical mucus to allow sperm through

Question 51

What does progesterone do?

Answer 51

Maintains thickness of endometrium Produces thick mucus Relaxes myometrium

Question 52

How long does spermatogenesis take?

Answer 52

70 days

Question 53

What hormones regulate spermatogenesis?

Answer 53

LH FSH Testosterone