Lecture 06: Female Reproductive Cycle (Kelleman)

Question 1

estrous cycle

Answer 1

reproductive cycle of non-primate species. Period from one estrus to the next.

Question 2

2 phases of estrous cycle

Answer 2

follicular and luteal

Question 3

estrous vs. estrus

Answer 3

estrous refers to the cycle, estrus refers to period of behavioral receptivity during the estrous cycle

Question 4

Monoestrous and species

Answer 4

one estrous cycle per year. Wolves, foxes, bears, most dogs

Question 5

polyestrous and species

Answer 5

repeated estrous cycles are uniformly distributed throughout the year. Cattle, swine, rodents

Question 6

seasonally polyestrous and species

Answer 6

repeated estrous cycles for a PORTION of the year. Horses, sheep, goats, cats

Question 7

anestrus

Answer 7

any time period when the female is not cycling

Question 8

cyclicity of seasonal breeders is determined by which environmental factors? What hormone do these factors directly influence?

Answer 8

photoperiod and temperature. Regulates melatonin secretion

Question 9

More melatonin is produced in darkness or light?

Answer 9

darkness!

Question 10

what produces melatonin?

Answer 10

pineal gland. It is an indoleamin hormone

Question 11

Short-day breeders and species

Answer 11

cyclicity occurs during fall months, give birth in spring. Sheep, goats

Question 12

melatonin stimulates or inhibits GnRH secretion in short day breeders? **

Answer 12

stimulates

Question 13

Long-day breeders and species

Answer 13

cycle in spring/summer and give birth in spring. Horses

Question 14

melatonin stimulates or inhibits GnRH secretion in long day breeders? ***

Answer 14

inhibits

Question 15

What does melatonin act on?

Answer 15

hypothalamus

Question 16

What hormone does hypothalamus release (in reference to cyclicity)?

Answer 16

GnRH

Question 17

What does GnRH act on?

Answer 17

pituitary gland

Question 18

What hormones are released by pituitary gland (in reference to cyclicity)

Answer 18

FSH, LH

Question 19

What do FSH and LH act on?

Answer 19

gonads

Question 20

What is reproductive cyclicity driven by?

Answer 20

secretion of hypothalamic and pituitary hormones

Question 21

How is progesterone used clinically?

Answer 21

used to make fake CL and keep animal out of heat

Question 22

Prostaglandin fx

Answer 22

luteolysis (killing off CL)

Question 23

FSH, LH, and inhibin are included in which class of hormones?

Answer 23

glycoproteins

Question 24

GnRH function

Answer 24

(released by hypothalamus) stimulates synthesis and secretion of LH and FSH from anterior pituitary gland

Question 25

FSH fx

Answer 25

(released from AP) promotes follicular development in the female.

Question 26

LH fx

Answer 26

(released from AP) causes final follicular maturation and ovulation. Promotes development and maintenance of CL

Question 27

What hormones inhibit FSH?

Answer 27

Inhibin, estrogen

Question 28

What hormone inhibits LH?

Answer 28

Progesterone

Question 29

Where is estrogen produced? Fx?

Answer 29

Produced in ovarian follicles. - Causes estrous behavior, ONLY when progesterone is low. - Inhibits FSH - High lvls cause GnRH and LH surge

Question 30

Where is progesterone produced? Fx?

Answer 30

Corpus luteum - Pregnancy maintenance - Inhibits estrous behavior - Inhibits GnRH, LH

Question 31

Where is prostaglandin produced? Fx?

Answer 31

Endometrium | -Causes destruction of CL

Question 32

Decreasing Prostaglandin --> GnRH

Answer 32

increases

Question 33

Which estrous phase has high progesterone?

Answer 33

luteal phase

Question 34

Which estrous phase has high estrogen?

Answer 34

follicular phase

Question 35

In which phase of estrous cycle does ovulation occur?

Answer 35

follicular phase

Question 36

2 subdivisions of follicular phase

Answer 36

Proestrus and estrus

Question 37

2 subdivisions of luteal phase

Answer 37

metestrus and diestrus

Question 38

Main events of proestrus

Answer 38

1) declining progesterone, rising estrogen 2) 3rd wave of follicles recruited, dominant follicle selected but doesn't ovulate yet 3) female attracts male but doesn't allow mating

Question 39

Main events of estrus

Answer 39

1) high estrogen, low progesterone 2) ovulation of dominant follicle occurs 3) female receptive and mating occurs

Question 40

Main events of metestrus

Answer 40

1) declining estrogen, rising progesterone 2) CL forming 3) female not receptive 4) 1st wave of new follicles recruited, but does not reach ovulation because of high progesterone

Question 41

Main events of diestrus

Answer 41

1) High progesterone, low estrogen 2) 2nd wave of follicles recruited, ovulation not reached because of high progesterone 3) female refuses male

Question 42

luteolysis and when it occurs

Answer 42

when no pregnancy, prostaglandin released by endometrium and CL destroyed. Occurs at end of diestrus

Question 43

Order of estrous cycle phases

Answer 43

Proestrus --> estrus --> metestrus --> diestrus "PEMD"

Question 44

How do rising lvls of estrogen feed back to surge center of hypothalamus? ***

Answer 44

Positive feedback loop. Estrogen --> GnRH --> LH --> ovulation and spinofollicular maturation

Question 45

How does inhibin released by dominant follicle feed back to hypothalamus?

Answer 45

negative feedback loop. Inhibits FSH