Estrous Cycle Wk 5 Flashcards
What are the 2 major phases of estrous cycle
- follicular phase
- luteal phase
What hormone is dominant in follicular phase?
- E2 dominant
- Ends at ovulation
What hormone is dominant in the luteal phase?
- P4 dominant because of the CL on the ovaries (CL are the source of progesterone)
- 80% of cycle
- Ends at luteolysis (breakdown of CL)
4 smaller stages of the estrous cycle are
- proestrus
- estrus
- metaestrus
- diestrus
Proestrus: what phase is this apart of and what hormone increases?
apart of the follicular phase, E2 increases and P4 decreases
follicular growth
Estrus phase most important part: what phase is this apart of and what hormone peaks?
- Follicular phase, sexual receptivity*
- Peak in E2
Metestrus: what phase is this apart of and what hormone increases?
Luteal phase, CL formation, increasing P4 and decreasing E2
Diestrus phase: what major phase is this apart of and what hormone is predominant?
- Luteal phase, CL fully functional, sustained high P4
Changes during estrus: physiological changes during estrus?
red swollen vulva
increased thin clear mucous
increased uterine tone
thickened vaginal epithelium
behavioural changes during estrus
vocalisation, roaming, mounting, tail elevation, urination, lordosis (cat posture with backside upwards)
What is anestrus?
condition defined by lack of cycling, where ovary has no ovulatory follicles or no corpora lutea*
What are causes of anestrus?
Pregnancy
Lactation
seasonal
undernutrition/stress effects
pathology -> genetic defect causing breakdown of HPG access?
Which stage follows ovulation and comes before rise in progesterone?
Metestrus -> P4 starts to increase but not significantly until diestrus phase
difference between monooestrous and polyoestrous and seasonally polyoestrous
- monoestrous = 1 cycle per year
- polyoestrous = many cycles per year
- monooestrous = dog, fox
- polyoestrous = cat, cows, pigs
- seasonally polyoestrous = mares (long day), ewes (short day)
length of cycle for queen -oestrous, estrus and ovulation days
17 days
estrus duration: 9 days
Ovulation: induced ovulation
