Female Gametogenesis

Question 1

IVF

Answer 1

In-vetro infertalisation

Egg and sperm come together in a test-tube

10% chance of live birth.

Question 2

Why is IVF needed more nowadays?

Answer 2

As people are trying for children later in life.

Average age of females wanting IVF is 36yo.

Question 3

ICSI?

Answer 3

There isn’t enough sperm therefore directly inject the sperm into the egg

Question 4

The female gential tracts parts?

Answer 4

Question 5

What are the different shapes names of the female genital tract?

Answer 5

Question 6

Oogenesis?

Answer 6

the process of which female gametes are produced.

takes many years to complete.

The female ovaries contains the primary oocytes.

Leads to the production of one ovum.

Question 7

Process of oogenesis?

Answer 7

4 daughter cells that are produced from the diploid primary occytes cell.

Primary occytes divides meitotically.

3 are significantly smaller than the 4th.

These smaller cells, called polar bodies, eventually disintegrate.

Leaving only the larger ovum as the final product of oogenesis

Question 8

When is the first polar body produces?

Answer 8

One of the 2 products of the first stage of meiosis.

Both are relatively small and contain little cytoplasm.

Question 9

Biological clock for?

Answer 9

The number of eggs a female can produce.

The quality of eggs a female can produce.

Both signfically decrease with age.

Question 10

Menstrual cycle?

Answer 10

Lasts for 28days (average length of time: varies).

Question 11

What are the 2 phases of the menstrual cycle?

Answer 11

Follicular phase

1st half of the cycle.

Maturation of the egg.

Luteal Phase

2nd half of the cycle

Development of the corpus luteum

Question 12

What does the corpus luteum do?

Answer 12

Keeps the levels of progesterone high until the placenta is developed

Question 13

What are the hormones produced by the female to help release an egg?

5 of them

Answer 13

1. GnRH (Honadotrophin releasing hormone).
2. FSH (Follicular stimulating hormone)
3. LH (Lutenising hormone)
4. Estrogen
5. Progesterone
   6.

Question 14

Gonadotrophin releasing hormone?

Answer 14

GnRH

Stimualtes FSH and LH synthesis from anterior pituitary.

Synthesised by neurones in the hypothalamus

Question 15

Follicular stimulating hormone?

Answer 15

FSH

Secreted by anterior pituitary

Stimulates follicular development

Thickens endometrium

Question 16

Lutensing hormone?

Answer 16

LH

Secreted by anterior pituitary

Peak stimulates ovulation

Stimulates corpus luteum development

Thickens endometrium

Question 17

Estrogen?

Answer 17

Secreted primarly by the ovaries, adrenal cortex and placenta in pregnancy.

Stimulates thickening of the endometrium

Responsible for the fertile cervical mucus.

Important for the development of secondary sex characteristics

Question 18

Progesterone?

Answer 18

Secreted by corpus luteum

Inhibits secretion of LH

Relaxes muscles (makes room in the uterus)

Responsible for infertile mucus.

Maintains thickness of endometrium

Question 19

Graphical representation of the interactions between the hormones?

Answer 19

See additional sheet 1

Question 20

Hormone levels during ovulation?

Answer 20

See additional sheet 2

Question 21

Characteristics of the follicular phase?

Answer 21

FSH stimulates follicular development

As dominant follicle develops, produces increasing amount of follicular fluid containing estrogen.

Increase estrogen serum supresses FSH secretion instead stimulates LH.

LH stimulates ovulation

Question 22

Luteal phase?

Answer 22

Follows ovulation

Cavity of the ruptured follicle is replaced by the corpus luteum.

Question 23

What happens if fertilisation does not occur?

Answer 23

Corpus luteum regress

Production of estrogen and progesteron decreases.

Stimulate production of FSH

New cycle

Question 24

Graphic represetnation on what happens to the follicle during the follicular and luteal phase?

Answer 24

see additional 3

Question 25

Define folliculogenesis?

Answer 25

Maturation of the ovarian follicle

Question 26

Define ovarian follicle?

Answer 26

Densely packed shell of somatic cells that conains an immature oocyte.

Question 27

Graphic representation of the development of the follicle?

Answer 27

See additional sheet 4

Question 28

Antral phase?

Answer 28

Theca cells develop LH receptors.

Granulosa cells develop FSH receptors and oestrogen receptors

Question 29

What is the positive feedback cycle when developing the follicle?

Answer 29

FSH stimulates granulosal proliferation.

Increase in FSH receptors and oestrogen synthesis.

Outer granulosa cells acquire LH receptors

Question 30

LH surge?

Answer 30

Secondary occyte and polar body.

Stops at metaphase 2 (only finished after fertilisation)

Question 31

Define theca cells?

Answer 31

Produces androgen which is converted by the granulosa to oestradiol

Oestrogen suppresses FSH production by the anterior pitutary.

Question 32

Define grenulosa cells?

Answer 32

Express LH receptor.

Increase levels of oestroen at mid cycle.

Cause hypothalamus to produce GnRH.

Causes LH and FSH surge

Question 33

Define primordial germ cells?

Answer 33

First found within the walls of the yolk sac when you were a zygote.

These cells will not function for several decades (till puberty)

Question 34

Define germ line?

Answer 34

A series of cells that form the sex cells

Question 35

What is important characteristic in the dormant oocytes?

Answer 35

Contains partially condensed prophase chromsomes.

Becomes large and watery- known as germinal vesicle.

Done to produce the oocyte’s DNA during the long period of meiotic arrest

Question 36

When is the oocyte produced?

Answer 36

The oocytes are all in dormant.

Produced primordial germ cells when embryo and during puberty convertion of these into dormant oocytes