Female Sex Hormones

Question 1

What happens in females in the absence of SRY protein?

Answer 1

Gonadal cortex becomes ovary

Question 2

What happens to females in the absence of testosterone?

Answer 2

Wolffian duct to degenerate

Question 3

What happens to females in the absence of anti-Mullerian hormone?

Answer 3

Mullerian duct becomes the fallopian tube, uterus + upper part of the vagina

Question 4

How long is the cycle?

Answer 4

28 days

Question 5

What are the 2 phases of the cycle?

Answer 5

Follicular cycle
Luteal cycle

Question 6

Describe the hormonal control of the early to mid follicular phase
1

Answer 6

Low levels of oestrogen exert negative feedback to GnRH, FSH + LH
Oestrogen promotes more oestrogen secretion by the follicle
AMH prevents more follicles from developing

Question 7

Describe the hormonal control the late follicular phase + ovulation
2

Answer 7

Rising levels of oestrogen + progesterone
= LH surge
FSH suppressed by inhibin

Question 8

Describe the hormonal control of early to mid-luteal phase
3

Answer 8

Combined oestrogen + progesterone shut off FSH + LH

Question 9

Describe the hormonal control of the late luteal phase
4

Answer 9

Oestrogen + progesterone fall when corpus luteum dies
Gonadotropins start follicular development of new cycle

Question 10

What is high during ovulation?

Answer 10

LH
FSH
Oestrogen

Question 11

What are the ovarian steroid hormones?

Answer 11

Oestrogens
Progestogens
Androgens

Question 12

How does oestrogen work?

Answer 12

Mediated by oestrogen receptor
Oestrogen receptor complex binds to specific hormone response element
Activates the transcription of target genes

Question 13

What is the function of oestrogen?

Answer 13

Development + regulation of female reproductive system + secondary sex characteristics
Maturation of germ cells
Provision of hormonal timing
Development of tissue for implantation
Establishment of milieu
Provision of hormonal influences
Anabolic effects on bone + cartilage

Question 14

What is fertilisation driven by?

Answer 14

Progesterone

Question 15

What happens during fertilisation?

Answer 15

Sperm
Fertilisation
Blastocyte attaches itself to uterine wall
Blastocyst is implanted in endometrium

Question 16

What happens after fertilisation?

Answer 16

Placenta secretes hCG

Question 17

What does hCG do?

Answer 17

Prevents corpus luteum from developing = progesterone + oestrogen secretion continued
Maintains integrity of uterine wall

Question 18

How does placental hormones maintain pregnancy?

Answer 18

hCG supports corpus luteum
Corpus luteum + placenta produce progesterone
Oestrogen synthesised by feto-placental function
Placental lactogen provides fuel for the baby

Question 19

How does placental lactogen work?

Answer 19

Placental growth hormone
Breaks down fats from mother for baby

Question 20

What secretes milk?

Answer 20

Alveoli cells
They are clustered in lobules

Question 21

What is E2 for in mammary gland development?

Answer 21

Ductal growth

Question 22

What is progesterone for in mammary gland development?

Answer 22

Alveolar proliferation

Question 23

What helps lactation?

Answer 23

Prolactin + oxytocin

Question 24

What is the production of oxytocin stimulated by?

Answer 24

Oestrogens
Inhibited by progesterone

Question 25

What is seen in menopause?

Answer 25

Irregular periods Ovaries fail to respond to FSH Number of follicles decrease Increase in FSH + LH to combat low oestrogen

Question 26

What are the symptoms of menopause?

Answer 26

Hot flushes Night sweats Decrease libido Irregular periods Mood swings Vaginal dryness

Question 27

How does COC work?

Answer 27

Inhibits follicular development + prevents ovulation

Question 28

How does POP work?

Answer 28

Prevent implantation Decrease amount + viscosity of mucus

Question 29

What is the mechanism for oral contraceptives?

Answer 29

Oestrogen + progesterone prevent eges from being released from ovaries Progesterone causes thinning of endometrium = prevents implantation Progesterone thickens mucus = prevents sperm reaching egg

Question 30

What do infertility drugs do?

Answer 30

Stimulate secretion of FSH + LH = stimulates maturation of follicles, ovulation + development of corpus luteum

Question 31

What are the labour-related drugs?

Answer 31

Oxytocin Selective beta adrenergic receptor antagonists

Question 32

What does oxytocin do? Labour

Answer 32

Enhances contractile activity

Question 33

What does selective beta adrenergic receptor antagonists do?

Answer 33

Prevent smooth muscle contractions

Question 34

When are selective beta adrenergic receptor antagonists used?

Answer 34

Preterm labour if gestation is >20 weeks