L3: Female Reproductive Physiology

Question 1

what factors keep follicles from developing between birth + puberty

Answer 1

• oocyte inhibiting factor OIF keeps oocytes in Prophase 1
• luteinizing-inhibiting factors LIF prevents granulosa cells from becoming luteal tissue

Question 2

layer of glycoproteins b/w oocyte and granulosa cells

Answer 2

zona pellucida

Question 3

as follicles mature, a fluid filled _________ develops within the granulosa cells

Answer 3

antrum

Question 4

what are the 2 phases of the ovarian cycle

Answer 4

follicular phase- maturing follicles
luteal phase- corpus luteum

Question 5

what are the 3 cell types within the maturing follicle

Answer 5

• primary oocyte
• inner layer of granulosa cells
• outer layer of theca cells

Question 6

when does the follicle start to become sensitive to FSH

Answer 6

after formation of the antrum

Question 7

occurs when follicular cells release enzymes that weaken the follicular wall

Answer 7

ovulation

Question 8

during ovulation, _____ drives differentiation into the corpus luteum

Answer 8

Leutinizing hormone

Question 9

what is the ‘yellow body’ observed during in the corpus luteum

Answer 9

storage of cholesterol

Question 10

corpus luteum: remaining follicular cells convert to luteal cells & produce large amounts of …?

Answer 10

steroid hormone

Question 11

what happens to the corpus luteum if no fertilization occurs

Answer 11

becomes corpus albicans = white body forms due to formation of fibrous tissue

Question 12

_______ ovulators have cycles regulated by internal hormonal cycles

Answer 12

spontaneous

Question 13

what hormone signals the release of gonadotropins in spontaneous ovulators

Answer 13

estrogen

Question 14

______ ovulators are animals that require copulation for ovulation

Answer 14

induced

Question 15

in induced ovulators, ______ replaces estrogen as the signal that releases gonadotropins

Answer 15

copulation

Question 16

hormone synthesis occurs during the _____ phase of the ovarian cycle

Answer 16

luteal

Question 17

LH stimulates _________ in the thecal cells of the corpus luteum

Answer 17

cholesterol desmolase

Question 18

FSH stimulates ______ in the granulosa cells

Answer 18

aromatase

Question 19

enzymes for _________ synthesis are only active during the luteal phase

Answer 19

progesterone
3B-hydroxysteroid dehydroxygenase

Question 20

negative feedback of _______ and _______ inhibits FSH secretion

Answer 20

estrogen + inhibin

Question 21

LH secretion gradually ________ during the follicular stage

Answer 21

increases

Question 22

the effects of ______ changes negative feedback to positive feedback, leading to an LH surge

Answer 22

estrogen

Question 23

what occurs during the LH stage

Answer 23

• meiosis of oocyte resumes
• prostaglandin release breaks down follicular wall
• follicular cells differentiate into luteal cells
• ovulation occurs!

Question 24

ovulation occurs following what stage

Answer 24

Luteal

Question 25

what hormone has a strong negative feedback and suppresses a second LH surge after ovulation

Answer 25

progesterone

Question 26

______ synthesis halts upon ovulation but the levels of this hormone gradually increase

Answer 26

estrogen

Question 27

After ovulation, in the absence of pregnancy, __________ causes a regression of the ______ in cows, horses, gaots and sheep

Answer 27

PGF2α, corpus luteum

Question 28

PGF2α has no role in what animals

Answer 28

primates, queens and bitches

Question 29

what inhibits PGF2α release from the uterus

Answer 29

pregnancy

Question 30

why do most animals lack a menstrual phase

Answer 30

due to overlap in the late luteal phase w/ the early part of the follicular phase

Question 31

what occurs during to the endometrium during the proliferative phase of the uterine cycle

Answer 31

endometrium regenerates

Question 32

what occurs to the endometrium during the secretory phase of the uterine cycle

Answer 32

becomes enriched w/ glycogen to nourish an incoming embryo

Question 33

during the follicular phase, the main hormone is ?

Answer 33

estrogen

Question 34

during the luteal phase, the main hormone is ?

Answer 34

progesterone

Question 35

LH stimulates the development and maintenance of ....

Answer 35

corpus luteum

Question 36

what hormones does the corpus luteum secrete

Answer 36

progesterone and estrogen

Question 37

ovulation occurs at the end of ...

Answer 37

estrous

Question 38

early post ovulatory phase during which corpus luteum begins to develop during the estrous cycle

Answer 38

Metestrus

Question 39

phase of mature luteal activity that begins 4 days after ovulation and ends with the regression of the corpus luteum

Answer 39

Diestrus

Question 40

phase of estrus cycle that begins after corpus luteum regression and ends w/ onset of estrus

Answer 40

proestrus

Question 41

phase of estrous cycle characterized by rapid follicle development that leads to ovulation and the onset of sexual receptivity

Answer 41

proestrus

Question 42

what generates follicular waves

Answer 42

FSH

Question 43

dominant follicles are more sensitive to FSH since they have more _______, and thus are selected for further development

Answer 43

FSH receptors

Question 44

FSH stimulates ______ cell growth, increases _______ activity and synthesizes ______ to produce estradiol

Answer 44

granulosa cell growth increase aromatase activity synthesize inhibin to produce estradiol

Question 45

inhibin blocks _______ synthesis / secretion

Answer 45

FSH | inhibin represents a parallel neg feedback mech besides estrogen

Question 47

when _____ is high, it inhibits final development and ovulation

Answer 47

progesterone

Question 48

if _____ is low, the dominant follicle can enter ovulation

Answer 48

progesterone

Question 49

in induced ovulators, how does mating induce ovulation

Answer 49

via neural stimuluation of GnRH which leads to LH surge and then ovulation

Question 50

what event signals the end of the follicular phase and the beginning of the luteal phase

Answer 50

rupture of the follicular wall

Question 51

what 3 things facilitate ovulation

Answer 51

hyperemia collagenase synthesis by theca cells prostaglandin release

Question 52

prostaglandin is released by the ______ and stimulates what

Answer 52

ovary smooth muscle contractions

Question 53

upon stimulation by FSH, granulosa cells convert ______ into _______

Answer 53

androgen into estrogen

Question 54

In what animals does PGF2α cause the regression of the corpus luteum at ~14days

Answer 54

cows, horses, sheep, goats, pigs

Question 55

at what age to queens reach sexual maturity

Answer 55

4-12 months

Question 56

when does estrus occur

Answer 56

following the end of ovulation, during a period of high estrogen release from mature follicles

Question 57

what must occur right before ovulation

Answer 57

LH surge

Question 58

what are the stages of the follicular wave

Answer 58

1. recruitment phase 2. selection 3. dominance 4. atresia

Question 59

during the follicular wave, what makes a follicle dominant

Answer 59

greater sensitivity to FSH due to having more FSH receptors

Question 60

explain the feedback mechanism between FSH and inhibin

Answer 60

FSH synthesizes inhibin, inhibin blocks FSH synthesis and secretion

Question 61

during the follicular wave, what does FSH stimulate

Answer 61

* granulosa cell growth * increases aromatase activity * synthesize inhibin * produce estradiol

Question 62

what stimulates the follicular selection phase of the follicular wave

Answer 62

follicular growth (stimulated by FSH)

Question 63

how does the recruitment phase of follicular waves vary between cows+horses vs other sepcies

Answer 63

cows+horses: one follicle is selected to beocme the dominant follicle while the rest become atretic other species: more than one follicle is selected, multiple dominant follicles