Female Repro Physiology I Flashcards
Which species have polyestrus cycles (year-round)?
Cow, pig, and rodent
Which species have long day seasonal polyestrus?
Horse
Which species have short day seasonal polyestrus?
Sheep, goat, deer
Which species have monestrus?
Dog
Describe silent heat; in which species and when does it occur?
Sheep after anestrus
Cow postpartum
Cycle without behavioral estrus due to lack of P4
Normal cycles resume after CL produces P4 during luteal phase
Follicular waves
Follicular growth during luteal phase that does NOT form ovulatory follicles
Proestrus
FSH promotes development of ovulatory follicle/estrogen production
Estrus
Ovulatory follicles produces estrogen
Culminates in LH spike and ovulation
Metestrus
Newly-ovulated follicle becomes CL and begins to secrete progesterone
Diestrus
Longest stage of estrous cycle
CL produces high levels of progesterone
If no pregnancy, CL lysed by PGF2a
Which species are induced ovulators?
Cat, camelids, rabbits, ferrets
Ovulation in the cat
Enters estrus every 17 days Estrus lasts 7-9 days No ovulation/luteal phase unless mated Pregnancy lasts 60 days Estrus occurs through lactation
What is the consequence of not breeding ferrets?
Prolonged estrus/estrogen production Aplastic anemia (bone marrow does not produce RBCs)
Rat estrous cycle
4-5 days
If unmated, CL lasts 4 days
If mated, prolactin maintains CL
Only one follicular wave per cycle
Three main differences between estrous and menstrual cycle
1) Follicular phase is longer (50% of menstrual cycle vs 20% of estrus cycle)
2) Endrometrial sloughing after luteolysis in menstural
3) Uniform sexual receptivity in menstrual, unlike estrous cycle
The equivalent of Leydig cells in females are
Thecal cells
The equivalent of Sertoli cells in females are
Granulosa cells
The decrease in progesterone due to luteolysis causes
an increase in GnRH
What stimulates the release of PGF2a?
Oxytocin
From where does PGF2a come in most animals? In primates?
Most animals: uterus
Primates: ovaries
Describe FSH levels in the follicular phase of the estrous cycle
Proestrus: FSH rises gradually, then drops suddenly at the end of the phase
Estrus: FSH spikes and drops again (think bell curve)
Describe GnRH production by the tonic center
Luteal phase: Episodes every 4-8 hours
Follicular phase: Episodes every 1.5-2 hours
