Oogenesis

Question 1

What is the purpose of follicular fluid?

Answer 1

Regulate the function
Maturation of the oocyte
Prepare follicule
Stimulatory/inhibitory factors
environment for sperm capacitation

Question 2

What are the two purposes of the ovary?

Answer 2

Cyclic production of ova

Production of steroid hormones

Question 3

Which follicule is responsible for the largest amount of estrogen?

Answer 3

Largest follicle

Question 4

How many follicles does each species usually ovulate?

Answer 4

Cows-One
Sheep-One or two
Sows- 20-30
Mares-One, two is more common than we think

Question 5

What is the final follicle growth length?

Answer 5

12-34 days but could take 6 months

Question 6

The antrum formation and final growth depend on what?

Answer 6

Gonadotropins

Question 7

What does the hormonally induced proliferation and differentiation of theca and granulosa cells lead to?

Answer 7

Follicles become able to produce Estradiol and respond to FSH and LH

Question 8

What will follicles that produce Estrodiol gain that is necessary for ovulation and lueinizatin?

Answer 8

LH receptors

Question 9

What are the three Dynamics of antral follicles?

Answer 9

Recruitment
Selection
Dominance

Question 10

What are the three purposes of the steroid hormones made by the ovary?

Answer 10

1) Maintain development of the genital tract
2) Facilitate migration of the early embryo
3) Secure embryo implantation

Question 11

Describe the Recruitment dynamic

Answer 11

A cohort of small antral follicles begin to grow and produce E2. Some of these follicles will undergo atresia.

Question 12

Describe the Selection dynamic.

Answer 12

The emerging of dominant follicles from the previously recruited antral follicles. They may become atretic or dominant.

Question 13

Describe the dominance dynamic.

Answer 13

Selected follicles proceed towards becoming dominant as they make more E2 and inhibin.

Question 14

How is dominance characterized?

Answer 14

One or more preovulatory follicles exert a major inhibtory effect on the other antral follicles from the recruited and selected cohort.

Question 15

How long does the follicular wave take in comparison to the estrus cycle.

Answer 15

It takes 20% of the estrus cycle

Question 16

T/F

Follicular growth and atresia occur throughout the estrus cycle.

Answer 16

True

Question 17

What happens to follicles during metestrus?

Answer 17

A group of follicles is recruited but they become atretic

Question 18

When can Ovulation not occur?

Answer 18

When P4 is high

Question 19

What happens to the follicle during diestrus?

Answer 19

second follicular wave starts to develop but also undergo atresia. Makes a small amount of E2.

Question 20

What is GnRH?

Answer 20

Gonandotropin Releasing Hormone

Question 21

Where is GnRH produced?

Answer 21

The brain’s hypothalamus

Question 22

How is GnRH released when P4 is high?

Answer 22

It is released slowly, causing FSH and LH to be released slowly

Question 23

When do the third wave of follicles develop?

Answer 23

After luteolysis, and one or more follicles will develop into the preovulatory follicle

Question 24

When do follicular waves of antral follicles occur?

Answer 24

Prepubertally, during pregnancy, anestrus and postpartum recovery

Question 25

When is the second rise in FSH?

Answer 25

20-30 hours after the preovulatory surge of LH and FSH

Question 26

Cystic ovaries have high levels of what?

Answer 26

Androstenedione

Question 27

T/F Ovarian Follicle secrete numerous proteins?

Answer 27

True

Question 28

What is Follicular fluid?

Answer 28

Serum transudate that contains steroids and glycoproteins

Question 29

Where are the steroids and glycoproteins found in the follicular fluid synthesized from?

Answer 29

Follicular wall

Question 30

What happens to the hormones of large antral follicles as ovulation approaches?

Answer 30

E2 and P4 levels are high

Question 31

What are the functions of follicular fluid?

Answer 31

``` Regulate granulosa cells Prepare follicle for the corpus luteum formation Mature the oocyte Ovulation Sperm capacitation Egg transport to the oviduct ```

Question 32

What makes up follicular fluid?

Answer 32

Oocyte maturation inhibitor Relaxin Luteinization inhibitor Inhibin

Question 33

What are the four phases of oocyte maturation?

Answer 33

Mitotic Division, Nuclear Arrest, Cytoplasmic Growth, Resumption of Meiosis

Question 34

T/F Germ cells are mitotically divided before and after birth.

Answer 34

False only before birth. The female is born with all the eggs she will ever have

Question 35

Why is the last mitotic division important?

Answer 35

Because the new primary oocyte enters meiotic prophase

Question 36

What happens in the phase of prophase arrest?

Answer 36

Meiotic prophase is stopped and the oocyte nucleus becomes dormant until puberty

Question 37

Describe the cytoplasmic growth phase

Answer 37

The primary oocytes accumulate larger volumes of ctyoplasma and devolp the zona pellucida

Question 38

Where are Gap junctions formed?

Answer 38

Between plasma membrane oocytes and granulosa cells

Question 39

After ovulation several granulosa cells are still on the oocyte. What are these called?

Answer 39

The corona radiata

Question 40

What frees the oocyte from the granulosa layer during ovulation?

Answer 40

Cumulus cell dissociattion

Question 41

How long after the LH surge does meiosis occur?

Answer 41

3 hours

Question 42

What occurs about 2 hours before ovulation?

Answer 42

Granulosa cells penetrate through the lamina basalis and prepare for the invasion of the theca cells

Question 43

What is the stigma?

Answer 43

The area of the follicle apex that becomes thin and ruptures releasing follicular fluid and oocye

Question 44

What is needed to stimulate collagenase activity?

Answer 44

P4

Question 45

PGF2a is needed for what?

Answer 45

To rupture the follicle

Question 46

Preovulatory follicle undergo what three changes during ovulation?

Answer 46

Cytoplasmic and nuclear maturation Disruption of cumulus cells Thinning and rupture of the wall