Female Reproductive System

Question 1

What are the functions of the uterus?

Answer 1

• maintenance of foetus during development
• expelling foetus at end of pregnancy
• major female hormone-responsive reproductive organ

Question 2

What is the size of the uterus at the third trimester compared to at the start?

Answer 2

50cm vs 0.1cm

Question 3

What is the duration and frequency of periods?

Answer 3

between 2-7 days every 28 days

Question 4

How many periods does a woman normally undergo?

Answer 4

~450

Question 5

What does each follicle contain?

Answer 5

one oocyte (unfertilised egg cell)

Question 6

How many egg cells do the ovaries hold at different stages of development?

Answer 6

• midgestation = 6-7 million
• at birth = 2 million
• at puberty = 400,000

Question 7

What are the 2 alternative phases of the ovarian cycle?

Answer 7

• follicular phase – dominated by presence of maturing follicles
• luteal phase – characterised by presence of corpus luteum

Question 8

Which hormones do the ovaries produce and what do they do?

Answer 8

oestrogen and progesterone which act together to promote fertilisation of the ovum and to prepare the female reproductive tract for pregnancy

Question 9

What is oogenesis?

Answer 9

the signalling pathway that causes maturation of the ovum

Question 10

What is a follicle?

Answer 10

the combination of the developing egg (oocyte) and surrounding granulosa cells

Question 11

What does GnRH do?

Answer 11

stimulate the anterior pituitary to release LH and FSH

Question 12

What do FSH and FSHR combine to produce?

Answer 12

oestradiol

Question 13

What type of hormone are FSH and LH?

Answer 13

peptide hormones

Question 14

What does FSH do?

Answer 14

• aid in follicle growth and maturation
• induce antrum formation

Question 15

What is the antrum?

Answer 15

fluid-filled space that develops among the follicle cells and where oestrogen is stored

Question 16

What does inhibin do?

Answer 16

regulate the development of the follicles by inhibiting FSH secretion resulting in a surge in LH secretion

Question 17

What do rising levels of oestrogen act on?

Answer 17

• hypothalamus to inhibit GnRH secretion (decrease FSH, LH)
• pituitary to inhibit FSH secretion

Question 18

What happens as the follicle matures?

Answer 18

rising high levels of oestrogen act on the hypothalamus and pituitary to increase GnRH and selectively stimulate LH secretion (positive feedback)

Question 19

What does the corpus luteum do under the influence of LH?

Answer 19

secrete both oestrogen and progesterone

Question 20

What does progesterone do?

Answer 20

inhibit both LH and FSH secretion

Question 21

What happens when there is no LH or FSH?

Answer 21

new follicular maturation and ovulation is prevented then the corpus luteum degenerates and no oestrogen or progesterone is produced i.e. the negative feedback is inhibited and a new follicular phase then begins

Question 22

What are the 8 stages of the ovarian cycle?

Answer 22

1. GnRH produced by hypothalamus
2. FSH and LH produced by anterior pituitary
3. slightly elevated oestrogen and inhibin levels
4. high oestrogen level positively regulates GnRH secretion
5. LH surge
6. ovulation
7. unfertilised egg is removed during the period
8. oestrogen, progesterone and inhibin negatively regulate GnRH secretion

Question 23

What does the menstruation cycle do?

Answer 23

prepare the female reproductive tract for fertilisation and implantation of an ovum

Question 24

What are the 3 phases of the uterine cycle?

Answer 24

1. menstrual phase
2. proliferative phase
3. secretory phase

Question 25

What is ovulation?

Answer 25

when the egg is released via high levels of LH

Question 26

What do remnants of the follicles do?

Answer 26

make progesterone which thickens the uterus lining in preparation for implantation of a fertilised egg

Question 27

What happens as progesterone levels increase?

Answer 27

the body temperature increases by 0.5ºC

Question 28

When does ovulation begin?

Answer 28

~10-14 days before menstruation

Question 29

What is puberty triggered by?

Answer 29

increased level of GnRH

Question 30

What are the signs of puberty?

Answer 30

- thelarche (earliest) – development of breasts - pubarche – growth of pubic and axillary hair - menarche – the first menstrual period

Question 31

What changes does puberty cause?

Answer 31

- growth of the secondary sex organs - fat deposition (especially around the hips) - rapid increase in height (growth hormone)

Question 32

What is menopause?

Answer 32

a decrease in hormone secretion that occurs between the ages of 45-55

Question 33

What are the signs of menopause?

Answer 33

- cessation of menstrual cycles (12 months after last menstrual period) - gradual atrophy of genital organs - vasomotor changes (regulation of blood vessel dilation and constriction leading to hot flushes) - skin changes - psychological, emotional changes - ↑ cholesterol levell – risk of cardiovascular disease - ↑ risk of osteoporosis (decreased bone mass due to less oestrogen)

Question 34

What can be used to treat menopause?

Answer 34

hormone replacement therapy (HRT)

Question 35

What is amenorrhea?

Answer 35

a lack of menstrual bleeding characterised by the failure of onset of menstrual periods by age 16 (e.g. Turner’s syndrome)

Question 36

What can accompany menstruation?

Answer 36

- dysmenorrhea (pain) - menorrhagia – excessive bleeding e.g. uterine fibroids - metrorrhagia – vaginal bleeding e.g. prior menopause

Question 37

What can infertility be caused by?

Answer 37

- disorders of central-hypothalamic-pituitary function - disorders of the ovary - disorders of the uterus, uterine tubes and vagina

Question 38

What happens if the HPO is not synchronised?

Answer 38

the woman is unable to ovulate

Question 39

What do oestrogen disrupters do?

Answer 39

mimic the activity of oestrogen in the body’s cells

Question 40

What do oestrogen disrupters do in females, males and animals respectively?

Answer 40

- females = ↑ breast tumours - males = ↓ sperm count - animals = gender bending

Question 41

What does each endocrine gland in the female reproductive system produce?

Answer 41

- hypothalamus = GnRH - anterior pituitary = FSH and LH - ovaries = oestrogen, progesterone, inhibin and androgen

Question 42

What are the development and transition stages in males and females?

Answer 42

- males = descent of testes, puberty - females = puberty, menopause