Female Repro Flashcards
Define estrous cycle
repro cycle controlled by hormones that includes a period of heat, followed by ovulation, and complex changes of the uterine lining
What 4 things does the estrous cycle include
behavioral heat
events between heats
ovulation
changes in uterus
What two broad categories of hormones control the estrus cycle
ovarian and CNS
Define anestrus
time when an animal is not exhibiting estrous cycles
True/False: anestrous immediately follows estrous
false, anestrous is not part of the estrous cycle
Why would an animal be in anestrous (3)
if the animal is a seasonal breeder
pregancy/lactation/presence of offspring
stress/pathology
What are the three types of estrous cycles
polyestrous
seasonally polyestrous
monestrous
Define transition
those time periods just prior to or just after anestrous
what is the hallmark of transition
irregular estrous cycles
What is the main event of the follicular phase
growth and maturation of ovulatory follicles
the follicular phase is between _____ and _____
luteolysis and ovulation
what anterior pituitary hormone induces the formation of the ovulatory (graafian) follicle
FSH
the ovulatory follicle produces _____ which elicits ____
estrogen, heat/estrous
Without progesterone, ____ can spike and induce ovulation
LH
What is the main event of the luteal phase
growth and development of the CL
What does the CL produce
progesterone
The CL is eventually lysed by what molecule
PGF2alpha
True/False: there are some follicular growth during the luteal phase and ovulatory follicles can form
false, there is some follicular growth but ovulatory follicles cannot form
What is the main event of proestrous
growth of preovulatory follicles
What hormone influences the development of the ovulatory follicle
FSH
What produces estrogen
ovulatory follicle
what hormone predominates during estrous
estrogen
when does an LH spike occur
at the end of estrous to induce ovulation
what hormone induces ovulation
LH
What is the longest stage of the estrous cycle
diestrous
What hormone predominates during diestrous
progestrone
what structure produces progesterone
the CL
At what stage is the CL lysed by PGF2alpha
at the end of diestrous if a pregnancy has not been established
True/False: multiple groups of follicles develop during the estrous cycle
true
What species are induced ovulators
domestic cats, camelids, rabbits, ferrets
What two things cannot occur in induced species unless mated
ovulation and CL formation
True/False: a queen will not go into diestrous unless mated
true
What do theca cells make
androgens (testosterone)
What do granulosa cells make
-AMH
Inhibin
Activin
Estrogen
decreased P4 will ____GnRH from the tonic center
increase
increased estradiol will _____ GnRH from the surge center
increase
True/False the surge center has a single pulse per estrous cycle
true
E2 and Inhibin secreted by the follicle in the ovary exerts negative feedback on what pituitary hormone
FSH
True/False: only the dominant follicle in the wave produced at the end of the estrous cycle ovulates
true
A surge of what hormone leads to ovulation
LH
What can be used to induce superovulation
exogenous FSH
What do growing follicles secrete
inhibin
The large selected and dominant follicles are ____ dependent rather than _____ dependent
LH, FSH
True/False: recruited, selected, and dominant follicles all produce E2
true
At want stage of follicle growth does FSH secretion from pituitary predominate
recruitment
Follicular wave formation is _____
spontaneous
True/False: follicular wave formation cannot occur outside the estrous cylce
false, it can
What physiological states will you see follicular waves outside of estrous
-prepuberty
-during pregnancy
-during anestrous
-puerperium (period just after delivery)
Describe the two cell model of estrogen production
-LH stimulates theca cells to produce testosterone
-testosterone diffuses into granulosa cells
-FSH stimulates granulosa cells to produce aromatase the converts testosterone to E2
Where is testosterone converted to estrogen
granulosa cells
What are the effects of estrogen on the female repro tract
-hyperemia
-genital swelling
-changes in electrical conductivity
-leucocytosis
-increased mucous secretion
-increase uterine gland growth
-increased myometrial tone
true/false: you will not see uterine edema in the mare
false
what species does diapedesis occur in
dogs
what part of the estrous cycle does diapedsis occur in
proestrous
Define diapedesis
the passage of blood cells through the intact walls of the capillaries
True/false: diapedesis is the same as menstral bleeding
FALSE
the female estrous behavior occurs only during ____
estrous
What is lordosis
when a receptive female “stands” for a male
Briefly describe how induced ovulation works
-copulation
-sensory inputs to spinal cord
-relayed to hypothalamus surge center
-with enough stimuli large amounts of GnRH secreted
-LH spike
-ovulation
In what species is there no diestrous
in induced ovualtors, cats, camelids, rabbits, ferrets
How could you medically induce ovulation
-GnRH
-LH
-hCG
What hormone acts like LH and can induce ovulation in animals
hCG
What two molecules are responsible for uterine hyperemia and edema
Histamine
PGE2
What are the physiological effects of PGF2alpha
increase follicualr pressure and follicular wall weakening to induce lutelysis
Why is histamine necessary for ovulation
it increases follicular pressure aiding in lutelysis
How would NSAIDS affect fertility
could cause infertility because it would block the production of PGF2alpha which is necessary for ovulation
What change occurs in theca cells after the LH surge
they change from producing testosterone to producing progesterone
What hormone is necessary in the production of collagenase
progesterone
why is collagenase necessary for ovulation
because it breaks down the collagen at the area of the stigma (where the follicle emerges from)
What is the stigma of an ovary
where the rupture of the follicle occurs allowing ovulation
Define cumulus expansion
dissociation of cumulus from mural granulosa cells
oocytes are arrested at ____ since birth
meiosis I
what is the second arrest of the oocyte
metaphase II
True/False: an oocyte can make it through meiosis even without fertilization
false, it must be fertilized to make it through meiosis II
What lifts the meiosis I arrest
the LH surge
What lifts the meiosis II arrest
fertilization
What is the main event of the luteal phase
formation of the CL via luteinization
What is a corpus hemorrhagicum
when the follicle ruptures, there is an invasion of thecal vessels into the follicle as well as some rupture of this vasculature
what hormone governs luteinization
LH
What is luteinization
breakdown of the basement membrane between theca and granulosa cells
what are the general steps of forming the CL
-breakdown of the basement between theca and granulosa cells
-formation of corpus hemorrhagicum
-functional CL
what cells turn into the large luteal cells? small?
granulosal cells turn into the large and the thecal cells turn into the small luteal cells
True/False: insufficient progesterone can not support pregnancy
true
what hormone does the CL produce
progesterone
What foundational molecule do you need to make progesterone
cholesterol
At what stage of the estrous cycle does P4 increase
diestrous
True/False: the CL is always receptive to PGF2alpha in progesterone production
false, it is not responsive for the first 5-7 days
How does maternal recognition of pregnancy affect P4 levels
it ensures that it remains high through pregnancy
True/false: graafian follicles can form during the luteal phase
false, dominant follicles can form but not graafian
With only ____ GnRH there is no ovulation
tonic
What are the inhibitory effects of P4? (4)
-reduces GnRH pulse frequency from the tonic center
-prevents preovulatory LH surge
-prevents behavioral estrous
-reduces myometrial contractions
In seasonal breeders what dictates whether or not GnRH is secreted?
melatonin, but more specifically the kisspectin neural response to melatonin depending on if the animal is fall or spring
What happens if kisspectin neurons are stimulated
stimulates GnRH production
When does the ova travel to the uterous
early blastocyst stage
where does alot of early embryo development take place
oviduct
True/False: the zona is retained during ova development
false it is lost after “hatching”
What part of the blastocyst becomes fetus and what part becomes placenta
the inner cell mass becomes the fetus and the trophoblast becomes the placenta
What must happen for a successful maternal recognition of pregnancy
-conceptus must signal to prevent initiation of another cycle
-must occur before luteolysis
True/False: P4 can be produced by the placenta in some species
true
True/False: P4 rises and falls throughout pregnancy
false, it remains elevated
When does P4 drop during pregnancy
abruptly prior to parturition
Administration of what will cause abortion at any stage of genstation?
prostaglandins
What is P4 effects on mammary glands
stimulates lobuloalveolar growth
True/False: P4 causes milk secretion during lactation
false, only prolactin does that
What two species do we see pseudopregnancy occur most frequently in
dogs and cats
what is pseudopregnancy
exagerated diestrous response
what mechanism causes pseudopregnancy
the CL remains functional for a prolonged period of time almost equivalent to that of pregnancy
What 5 main hormones does the placenta secrete
-profestins
-estrogens
-eCG in horses
-lactogen
-relaxin
Why would you use hCG in vet med
acts like LH so for luteinizing activity
what acts like FSH when given to other species
eCG
What species produce placental lactogen
ruminants
what are the two main functions of placental lactogen
fetal growth and stimulates mammary gland
What is the function of relaxin
causes softening and relaxation of pelvic ligaments
relaxin is not found in ____ but in ____ in ruminants
placenta, CL
What is the only anterior pituitary hormone to change levels during pregnancy
prolactin
