Reproductive System

Question 1

What’s the difference between the types of sex steroids testes and ovaries produce

Answer 1

Testes secrete mostly androgens and some oestrogens

Ovaries secrete more oestrogen and also secrete progesterone

Question 2

Which two steroid hormones control spermatogenesis and also oogenesis (formation of egg and sperm)

Answer 2

LH and FSH

Question 3

What’s the difference majorly in spermatogenesis and oogenesis

Answer 3

Oogenesis happens cyclically every 4 weeks new egg released

Sperm continuous reproduction

Question 4

What is connected to the ovaries

Answer 4

Fimbriae (end of Fallopian tube)

And the Fallopian tube

Question 5

Which layer on the uterus is shed during menstruatikn if no fertilised egg present

Answer 5

The endometrium

Question 6

What is the muscle layer of the uterus called (which oxytocin allows contraction of)

Answer 6

Myometrium

Question 7

Which part of meiosis does the oocyte stop at before it develops into secondary and then ovum within the ovaries

Answer 7

Prophase I

Question 8

Explain the structure of the oocytes which later become the ovum in oogenesis

Answer 8

They exist as primordial follicles

The oocyte is surrounded by Stroma cells and follicular cells

Question 9

Why are you born with many more oocytes than acctually later develop into a matured egg released

Answer 9

Most oocytes die before puberty or after the first menstruation due to programmed cell death

Question 10

What is the ovarian cycle and what is it in sync with

Answer 10

The maturation of oocytes into the ovum and release of the ovum into Fallopian tube

It is in sync with the uterine cycle/menstrual cycle

Question 11

What is the phase called which is the development of the primordial follicles

Answer 11

The follicular phase

Question 12

What happens in the pre Antral follicular phase

Answer 12

Primordial follicle develops into a primary follicle due to paracrine factors released causing growth into a primary follicle

Question 13

Which hormone stops all primordial follicles developing into primary follicles

Answer 13

Antimullerian hormone produced by primary follicles themselves

Question 14

Explain the structure of the primary follicle in the pre Antral follicular phase

Answer 14

Oocyte becomes surrounded by granulosa cells

And a zona pellucida glycoprotein layer

Question 15

Why is the zona pellucida of the primary follicle important

Answer 15

Because it acts as a sperm binding site for fertilisation

Question 16

How do cells communicate in the primary follicle

Answer 16

Gap junctions

Question 17

How does a matured pre Antral follicle differ from a primary follicle

Answer 17

Thicker layers of granulosa cells

Thecal cells appear

Zona pellucida stays the same

Question 18

How do granulosa cells form thecal cells

Answer 18

Release paracrine factors into the stroma cells and these form thecal cells

Question 19

What happens in the antral phase of the follicular phase

Answer 19

Thecal cells become apparent

Thicker pellucida

Thicker granulosa cells

Fluid filled sac within the granulosa cells appears

Question 20

How does stimulation of growth differ in antral to pre antral folliclular phase

Answer 20

No longer dependant on paracrine factors and due to

FSH hormone

Question 21

What does FSH do in the antral late phase of follicular phase

Answer 21

Triggers production of LH receptors on granulosa cells

Increases expression of aromatase enzyme which converts androgens into oestrogens in granulosa cells

Question 22

Which hormone produced in the ovaries by thecal cells in high production causes hypothalamus stop releasing more FSH

Answer 22

Oestrogen

Question 23

Which cells actually produce the androgens converted to oestrogens in granulosa cells

Answer 23

Thecal cells

Question 24

What does decrease in FSH when too much oestrogen is produced from androgen in granulosa cells cause

Answer 24

Cell death in most antral follicles causing dominant one to be chosen for release

Question 25

What surrounds the oocyte in the dominant follicle

Answer 25

Pellucida glycoprotein layer and corona radiata

Question 26

What does LH response by dominant follicle cause

Answer 26

Undergoes meiotic division up to metaphase 2 (forming secondary oocyte and polar body when it develops into ovum) Also lowers oestrogen in late follicular phase by inhibiting aromatase

Question 27

What does FSH cause pre ovulation cause important for ovum release

Answer 27

Causes cytokine production And hydrolytic enzymes released by thecal and granulosa cells = degrade the ovary wall

Question 28

When does oestrogen decrease

Answer 28

When LH and increases Or when FSH decreases

Question 29

What happens when the ovary wall and follicle ruptures

Answer 29

Corona radiata, ovum and the pellucida layer are released and took in via the fimbriae

Question 30

Why is the corona radiata important

Answer 30

Capture of egg by the fimbriae

Question 31

What does the ovary form when the ovum is released

Answer 31

Corpus luteum

Question 32

When are LH levels increased

Answer 32

When oestrogen has increased- it tries to eradicate this by causing thecal cells to produce more androgens Lowers oestrogen by inhibiting aromatase enzyme

Question 33

What happens in the luteal phase

Answer 33

Granulosa cells fill with lipid They produce progesterone Oestrogen decreases due to increased LH (stops aromatase) Then goes back to normal levels

Question 34

What happens to the corpus Leuteum if not pregnant

Answer 34

Forms corpus albicans and slowly degrades

Question 35

Why do LH and FSH increase when corpus albicans is produced

Answer 35

Because low oestrogen and progesterone due to less sterofenic tissues like granulosa cells can’t produce progesterone or oestrogen from androgens

Question 36

What happens in the luteal phase of pregnant

Answer 36

Placenta release human chorionic gonadotropin Allows corpus luteum to stay intact

Question 37

What is released in high frequencies of gonadotropin RH and low frequencies

Answer 37

FSH= high frequency (egg maturation) LH- low frequency = triggers ovulation

Question 38

Why is there high progesterone and oestrogen originally in the luteal phase

Answer 38

Because low LH before surge and also no feedback of oestrogen causes constant production

Question 39

Important functions of FSH

Answer 39

Stimulates growth of immature follicles Upregulates aromatase expression increasing oestrogen levels Induce expression of LH receptors in granulosa cells in the late follicular cells to allow ovulation

Question 40

Why do antral follicles die at fast rates

Answer 40

When oestrogen is produced in high amounts when FSH released this causes FSHbto stop being released and thus stops promoting follicle maturation

Question 41

What is the importance of LH in the late follicular phase

Answer 41

The surge is to stop oestrogen production further as it inhibits aromatase LH also needed to allow oocyte to go under division until metaphase II to form the matured ovum from secondary oocyte and polar body Low levels of LH allow progesterone secretion from granulosa cells in the luteal phase LH causes granulosa to secrete hydrolytic enzymes to degrade ovary wall

Question 42

Why is oestrogen important

Answer 42

Prepared the reproductive tract for potential fertilisation and pregnancy

Question 43

Why is progesterone important in luteal phase (due to low LH)

Answer 43

Promotes uterine secretions to maintain support for fertilised egg if pregnant

Question 44

When is LH high

Answer 44

When FSH is present and progesterone is not present

Question 45

Which hormones in granulosa cells in ovaries repress FSH production

Answer 45

Inhibin a and B

Question 46

What causes an LH surge pre ovulation

Answer 46

High levels of oestrogen increase LH due to low FSH frequency High levels of oestrogen then inhibited by LH