Female endocrinology 1 Flashcards
(29 cards)
Proestrus follows what & proceeds what?
Follows dioestrus & precedes oestrus
Major endocrine transition from what to what…?
From prog. dominance to oestrogen dominance
What event sets off oestrus? What event ends proestrus?
Begins when prog. declines as a result of luteolysis
Ends at onset of oestrus
In which phase does female allow mating ?
oestrus - length varies between spp.
Dominant hormone in oestrous?
oestradiol
What is standing oestrus?
female displays lordosis - back-arching behaviour in prep for mating & ‘stand strong’ when mounted
4 major events in follicular phase…?
- ++ gonadotropins
- follicular growth & maturation
- sexual receptivity & behaviour (oestrogen)
- ovulation
Re. oogenesis, where can maturation occur…?
follicular phase AND also mitotic & meiotic divisions occurring prenatally
What happens to oocytes after prenatal mitotic & meiotic divisions?
Nuclear arrest until puberty where meiosis resumes
What happens in the post-pubertal phase …?
post-pubertal phase - puberty (LH surge) -> meiosis continues
AND
ovulation & fertilisation occur
What happens before ovulation…?
nucleus of oocyte -> periphery
first polar body formed just before ovulation
How many chromosomes in a haploid cell
half
Draw summary diagram for all hormones & phases with focus on ‘follicular phase’
slide 19…
What happens in the follicular phase…?
decrease P4 from CL -> ++GnRH -> ++FSH & LH -> follicle (primordial follicles)
Antral follicle made up of which 2 types of cells?
Theca interna cells - LH receptors - produce T Granulosa cells - FSH receptors - produce enzymes that convert T -> oestradiol
Mare with Granulosa cells tumour
++oestrogen -> constant heat (nymphomaniacs) (remove ovary) = solution
Mare with Theca-cell tumour
++ testosterone -> stallion-like behaviour (rounding up mare’s, mounting mares..)
Proestral follicular dev.?
Follicles undergo growth & selection
Estradiol threshold level…?
horses & cows -> inhibin (inhibits growth & maturation of all follicles surrounding it) -> FSH decreases but LH continues production -> preovulatory surge
Effects of oestrogen…?
Changes in behaviour (lordosis, phonation, physical)
Changes in repro. tract (++blood flow, tissue oedema, ++mucous secretion, ++leukocytes, ++SM motility, ++uterine gland growth)
Changes in hypothamus
Draw summary diagram of LH surge….
slide 18…
Menopause is what?
When oocytes run out due to oocyte atresia
During recruitment, what are the hormone levels doing…?
high FSH, low LH, no inhibin, low oestrogen
During selection, what are the hormone levels doing…?
Low FSH, mod LH, low inhibin, mod oestrogen
