Follicular Physiology

Question 1

Which species is seasonally polyestrus?

Answer 1

Horse

Question 2

What are the 4 major events of the follicular phase?

Answer 2

1. Rising levels of GnRH release from anterior pituitary
2. Follicular growth/prep for ovulation
3. Sexual receptivity
4. OVULATION

Question 3

What is the major hormone in the Follicular phase?

Answer 3

Estrogen!

Question 4

What are the two main “players” of the follicular phase?

Answer 4

Tonic & Surge center of the hypothalamus

Question 5

What “turns on” the surge center of the hypothalamus?

Answer 5

Once E2 reaches a threshold level

Question 6

The tonic center releases small amplitude pulses of _____ that stimulate the release of ___ & ___ from the Anterior Pituitary.

Answer 6

The tonic center releases small amplitude pulses of GnRH that stimulate the release of FSH & LH from the Anterior Pituitary.

Question 7

FSH & LH cause the growth & development of ______, which produce______, on the ovary

Answer 7

Follicles, Estrogen

Question 8

The surge center responds in a positive feedback fashion to the increasing levels of _____ from the follicle in the absence of _____ to release large quantities of _____.

Answer 8

Estrogen, Progesterone, GnRH

The surge center responds in a positive feedback fashion to the increasing levels of ESTROGEN from the follicle in the absence of PROGESTERONE to release large quantities of GNRH.

Question 9

The large quantities of GnRH from the surge center causes the preovulatory ___ surge which leads to ____.

Answer 9

LH, Ovulation

The large quantities of GnRH from the surge center causes the preovulatory LH surge which leads to OVULATION.

Question 10

The proestrual follicular development, in response to FSH & LH, allows the follicle to release estrogen & _____ which then causes a decrease in _____.

Answer 10

Inhibin, FSH

Question 11

The increase in estrogen from follicular development has positive feedback on the _______.

Answer 11

Surge center of the hypothalamus

Question 12

The increase in estrogen from follicular development has negative feedback on _______.

Answer 12

FSH

Question 13

Progesterone has a _____ feedback at the level of the hypothalamus on GnRH.

Answer 13

Negative

Question 14

What happens to the following hormone’s levels during the follicular phase?

P4:
E2:
FSH:
LH:

Answer 14

P4: decrease
E2: increase
FSH: increases then sharply decreases before ovulation
LH: Increases at same rate as FSH and then increases sharply at the same time FSH decreases

Question 15

Process of choosing of small antral follicles from ovarian pool

Answer 15

Recruitment

Question 16

Process of choosing from the recruited follicles

Answer 16

Selection

Question 17

Selected follicles that do NOT undergo atresia but instead undergo ovulation

Answer 17

Dominant follicles

Question 18

Where the antrum disappears from an Antral follicle

Answer 18

Atresia

Question 19

What is the name, size , and amount of estrogen produce by the follicles that are recruited from the ovarian follicular pool?

Answer 19

F1

Question 20

What is the name, size , and amount of estrogen produce by the follicles that are selected from the F1 group?

Answer 20

F2
5-12 mm
Medium amount of E2

Question 21

What is the name, size , and amount of estrogen produce by the follicles that are dominant from the F2 group?

Answer 21

F3
>12 mm
Larges amount of E2

Question 22

What is the difference in the number of F3’s in a dog vs. a horse?

Answer 22

Horses only have 1, maybe two since they bear a single offspring

Dogs have multiples since they are litter bearers

Question 23

How does an F3 feel different from a CL?

Answer 23

F3 is more fluidy while a CL feels more like a gummy bear head and protrudes out more

Question 24

What are the levels of FSH, LH, Inhibin, and E2 during Recruitment?

Answer 24

FSH: High
LH: Low
Inhibin: 0
E2: 0

Question 25

What are the levels of FSH, LH, Inhibin, and E2 during Selection

Answer 25

All at medium levels

Question 26

What are the levels of FSH, LH, Inhibin, and E2 during dominance?

Answer 26

FSH: Low LH: High Inhibin: High E2: High

Question 27

What cell membranes does LH bind to on an antral follicle?

Answer 27

Theca interna cells

Question 28

What is LH broken down into at theca interna cell membranes by a protein kinase?

Answer 28

Testosterone

Question 29

What inner cell type of an antral follicle does testosterone, from the breakdown of LH, bind to?

Answer 29

Granulosa cell

Question 30

What binds to granulosa cells and causes the b/d of T4 to estrogen?

Answer 30

FSH

Question 31

The preovulatory LH surge causes an increased blood flow to ____ & _____ which creates _____.

Answer 31

Ovary & dominant follicle Edema

Question 32

The preovulatory LH surge causes an increase in ______ which causes the contraction of ovarian smooth muscle and release of lysosomal enzymes.

Answer 32

PGF2a

Question 33

The increase in PGF2a causes an increase in contraction of ____________ which in turns increases ______ pressure.

Answer 33

Ovarian smooth muscle; Follicular pressure

Question 34

What are the two causes of increased follicular pressure brought on by the preovulatory LH surge?

Answer 34

Increased ovarian smooth muscle contraction(from increased PGF2a) Edema(from increased blood flow to ovary & dominant follicle)

Question 35

The preovulatory LH surge causes a shift from E2 to ____ by the dominant follicle

Answer 35

Progesterone

Question 36

Progesterone increased by the preovulatory LH surge causes an increase in ______ which helps with follicle wall ______.

Answer 36

Collagenases; weakening

Question 37

What are the two causes of follicular wall weakening brought on by the preovulatory LH surge?

Answer 37

Release of lysosomal enzymes(brought on by PGF2a) Increase in Collagenases(brought on by progesterone)

Question 38

The increased follicular pressure and the weakening of the follicular wall associated with the preovulatory LH surge leads to _____.

Answer 38

Ovulation

Question 39

The preovulatory LH surge causes gap junction breakdown between _______ & _______.

Answer 39

Granulosa cells, Oocyte

Question 40

What are the 5 actions brought on by the preovulatory LH surge?

Answer 40

1. Increased PGE2 2. Increased blood flow to ovary & dominant follicle(also helped by the increase PGE2) 3. Increased PGF2a 4. Shift from E2 to P4 by dominant follicle 5. Gap junction b/d between granulosa cells & oocyte

Question 41

Females are born with primary oocytes which are arrested in the 1st meiotic division until what?

Answer 41

LH surge

Question 42

What does a primary oocyte become with an LH surge?

Answer 42

Secondary oocyte with 1st polar body

Question 43

What brings on the production of a 2nd polar body?

Answer 43

Ovulation-->2nd meiotic division

Question 44

What is a fertilized secondary oocyte called?

Answer 44

Zygote

Question 45

What is the only species that ovulates a primary oocyte?

Answer 45

DOGS!!!!!!!

Question 46

What type of oocyte do most species ovulate?

Answer 46

Secondary oocyte with 1 polar body