Lecture 4: Female Reproductive Physiology: The follicular phase Flashcards
What is the source of progesterone in follicular waves
Corpus luteum
Which cells are most sensitive to FSH and why?
Larger follicles with more FSH receptors
Does FSH and estradiol increase or decrease during recruitment
Both increase
Does FSH, estradiol, and inhibin increase or decrease during selection
FSH- decreases
Estradiol and inhibin increase
Does FSH, estradiol and inhibin increase or decrease during dominance phase
FSH- decreases
Estradiol and inhibin increase
Does FSH, estradiol and inhibin increase or decrease during atresia
FSH- increases
Estradiol and inhibin decrease
What stimulates follicle recruitment
FSH
What determines follicle selection
Number of FSH receptors
During selection ___decreases FSH
Inhibin
The dominant follicle will require ____ for ovulation
LH surge
What inhibits the LH surge
Progesterone
How will high progesterone impact GnRH/LH levels and what is the result
Will cause insufficient GnRH/LH thus inhibiting ovulation
When does the dominant follicle become if progesterone is high vs low
High progesterone- follicle becomes atretic
Low progesterone- LH surge and ovulation
What prevents the dominant follicle from ovulating
CL luteum releases progesterone which acts as negative feedback on anterior pituitary and hypothalamus
Follicle releases inhibin which acts as negative feedback on anterior pituitary and also releases estradiol which acts as negative feedback on anterior pituitary and hypothalamus
How does the feedback loop change after luteolysis
Changes from negative to positive feedback of estradiol, stimulate LH surge and then that stimulates ovulation
Ovulation corresponds to the events in the ___ cycle
Estrous
What is proestrus
Formation of ovulatory follicles and estradiol secretion
What stage of the estrus cycle does estrogen secretion peak
Estrus
At what stage in the estrous cycle does the CL form and secrete progesterone
Metestrus
At what phase in the ovarian cycle is there a sustained luteal secretion of progesterone, CL functioning optimally
Diestrus
Wha is anestrus
Sustained period when cyclicity stops stops—> pregnancy, nursing, season, inadequate nutrition, migration, stress, disease
What is the total # of days in queen estrus cycle
18 days
How many days is the proestrus period in the queen
8-10 days
How long is the estrus period in the queen and when does ovulation occur
Estrus- 9 days long
Ovulation: 27hr after mating
When does Metestrus and diestrus occur occur in the queen
No diestrus/metetrous
How long could a pseudo pregnancy in a queen last
42 days
How long is anestrus period in the queen
3-4 months
How long is gestation in the queen
60 days
What is the seasonal timing of the estrous cycle for queens
January-October
How long is the estrous cycle in the bitch
5.5-6.5 months
How long is the proestrus period in the bitch
9 days
How long is the estrus period in the bitch and when does ovulation occur
Estrus: 9 days
Ovulation on day 2 of estrus
How long is diestrus occur in the bitch
6-10 weeks in non-pregnant bitch
How long is pseudo pregnancy in the bitch
60-90 days after estrus
How long is anestrus in the bitch
2-9 months
How long is gestation in the bitch
63 days
What is the timing of the seasonal estrus cycle in the bitch
Generally non-seasonal with a spike in the spring
How long is the estrous cycle in the mare
21 days
How long is the proestrus period in the mare
2-3 days
How long is the estrous period in the mare and when does ovulation occur
Estrus: 4-8 days
Ovulation: 24hrs before end of estrus
How long is the metetrous period in the mare
2-3 days
How long is the diestrus period in the mare
10-12 days
How long is the gestation period in the mare
336 days
What is the timing of the seasonal estrous cycle in the mare
March-October