Female Reproductive System

Question 1

Describe the basic structure of the female gonads

Answer 1

Ovary and uterine tube

Question 2

What are the function of the gonads in females

Answer 2

Ovaries secrete large amount of oestrogen and small amounts of androgens
Production of gametes (oogenesis)

Question 3

What is the ovary

Answer 3

Contains oocytes and releases 1 egg per month

Question 4

What is the fimbriae

Answer 4

Connects ovary and fallopian tube, collects the released egg

Question 5

What is the fallopian tube/ uterine tube/ oviduct

Answer 5

Tube that takes the oocyte towards the uterus, fertilisation occurs in the fallopian tube

Question 6

What is the uterus

Answer 6

Where the fertilised egg implants

Question 7

What is the endometrium

Answer 7

The uterus lining that grows in preparation for implanting and is lost as menstrual blood if implanting does not occur

Question 8

What surrounds oocytes in the ovary

Answer 8

Primordial follicles

Question 9

What are the three phases of the ovarian cycle

Answer 9

Follicular phase, ovulation and luteal phase

Question 10

What is the ovarian cycle

Answer 10

The cycle that describes the maturation of oocytes and releases of androgens Production ovum

Question 11

What is the duration of the follicular phase

Answer 11

Several months

Question 12

What is the duration of ovulation

Answer 12

Few hours

Question 13

What is the duration of the luteal phase

Answer 13

12-15 days

Question 14

What happens during the follicular phase

Answer 14

Maturation of the follicles

Question 15

What happens during ovulation

Answer 15

Release of an ovum from the ovary to the fallopian tube

Question 16

What happens during the luteal phase

Answer 16

Formation of the corpus luteum

Question 17

What other cycle does the ovarian cycle occur in line with

Answer 17

Uterine cycle

Question 18

What are the three phases of the follicular phase

Answer 18

Pre antral phase, Antral phase, pre-ovulatory phase

Question 19

What happens during the pre antral phase

Answer 19

• number of primordial follicles recruited to develop
• paracrine factors stimulate growth
• Antimullerian hormone limits number of follicles developing at the same time
  -develop into mature pre antral follicles

Question 20

What happens during the antral phase

Answer 20

• Fluid filled atria appears, zona granulosa increases in layers, theca interna becomes more apparent and zona pellucida becomes thicker
• Growth dependent on Follicle stimulating hormone (FSH)
  Dominant follicle is selected and becomes steriodgenic gland
• Androgen production from cholesterol by Theca cells and conversion of androgen to oestrogen by granulosa cells

Question 21

What do theca cells catalyse

Answer 21

Androgen production from cholesterol

Question 22

Why can granulosa cells convert androgens to oestrogen

Answer 22

Contain aromatase

Question 23

What are the zona granulosa, zona pelluccida and theca interna

Answer 23

Layers of cells surrounding maturing oocyte

Question 24

What happens in the pre ovulatory phase

Answer 24

• Dominant follicle responds to a surge in Luteinizing hormone (LH) by completing meiosis 1 and arresting in metaphase of meiosis 2
• Haploid secondary oocyte and polar body produced
• FSH increases
  LH receptor and enzyme are expressed in granulosa cells, leading to progesterone production
• theca and granulosa cells release inflammatory cytokines and and hydrolytic enzymes

Question 25

What happens during ovulation

Answer 25

- inflammatory event erodes the wall of ovary and follicle - oocyte, zona pellucida and corona radiata are release into the peritoneal cavity before being captured by the oviduct - remnants of the follicle in the ovary form the corpus luteum

Question 26

What is the role of the corona radiata

Answer 26

Crucial for capture of oocyte by the fimbrae and movement in the oviduct

Question 27

What happens in the luteal phase

Answer 27

- corpus luteum develops - granulosa cells fill with lipid - progesterone is produced - oestrogen; initially decreases but then rebounds - hormone levels change dependent on pregnancy or not

Question 28

Why does oestrogen initially decrease before it rebounds in the luteal phase

Answer 28

Due to the LH surge

Question 29

What is the difference in the luteal phase between pregnancy vs no pregnancy

Answer 29

No preganancy- the corpus luteum degenerates into a corpus albicans, oestrogen and progesterone fall and FSH and LH rise Pregnancy- placenta releases chorionic gonadotropin which enables the corpus luteum to persist

Question 30

What are the important hypothalamic hormones in control of the ovarian cycle

Answer 30

Gonadotrophin releasing hormone (GnRH)

Question 31

What is the function of Gonadotrophin releasing hormone in the ovarian cycle

Answer 31

Acts on pituitary gland, pulsatile release, high frequency = LH and low frequency= FSH

Question 32

What are the important pituitary hormones

Answer 32

Follicular stimulating hormone (FSH) and luteinising hormone (LH)

Question 33

What is the functions of FSH

Answer 33

- stimulates immature follicle recruitment and growth - upregukatates aromatase activity and gene expression - induces expression of LH receptors in granulosa cells fill - prevents apoptosis of antral follicles

Question 34

Why is aromatase important

Answer 34

Conversion of androgen to oestrogen

Question 35

What is the functions of Luteinising hormone

Answer 35

- Acts on theca cells in follicles to promote androgen production - LH surge triggers ovulation - Acts on granulosa cells to secrete progesterone - maintains corpus luteum

Question 36

What are the important ovarian hormones

Answer 36

Oestrogens, progesterone and inhibin A and B

Question 37

What are the three oestrogens involved in the ovarian cycle

Answer 37

Oestradiol, oestriol and oestrone

Question 38

What is the function of oestrogens in the ovarian cycle

Answer 38

- prepares reproductive tract for fertilisation and pregnancy via growth of endometrium etc.

Question 39

What is the dominant hormone secreted in the follicular phase

Answer 39

Oestrogens

Question 40

What is the function of progesterone in the ovarian cycle

Answer 40

- promotes uterine and uterine and tube secretions to maintain and support fertilisation and egg implantation

Question 41

What is the dominant hormone secreted in the luteal phase

Answer 41

Progesterone

Question 42

Which ovarian hormones are secreted by granulosa cells

Answer 42

Inhibin A and B

Question 43

What are the function of inhibin A and B

Answer 43

represses FSH secretion

Question 44

Describe the hormonal control of the ovarian cycle in the luteal phase

Answer 44

- corpus luteum forms - high progesterone negatively feedback and blocks positive feedback of high oestrogen - so SH and LH levels drop - corpus luteum regresses - progesterone and oestrogen levels fall - negative feedback lifted and FSH rises