lect 14 female contraception Flashcards
to create contraceptives we manipulate which system for the release of what
endocrine system for the release of sperm or oocyte
major components of the endocrine system pertaining to contraception
GnRH (hypothalamus)–> LH, FSH (gonadotropic cell in anterior pituitary)–> testis, ovaries (gametogenesis, gonadal hormone production)
effect of LH and FSH on ovary
release of estrogen and progesterone, increase steroidogenesis, stimulate maturation of ovarian follicle
estrogen and progesteron stimulate what
folliculogenesis and secondary sex characteristics
negative feedback loop of HPO axis
negative feedback on hypothalamus and pituitary to reduce GnRH and LH and FSH
what does pulsatile mean for GnRH, LH, FSH
shape of the chemical message matters. rhythmic, intermittent propagation
FSH regulates what
follicle growth and maturation in the ovaries
primary follicles develop into what
oocytes
what happens to mature follicles
they get ovulated and become the corpus luteum
cells that surround to development of oocytes, make steroid hormones from interaction
granulosa and theca cells
theca cells make what
testosterone
granulosa cells make what
make estradiol from testosterone via aromatase
testosterone to estradiol process
cholesterol side chain cleavage to progesterone. progesterone becomes testosterone. aromatase makes estradiol from testosterone
what induces the production of estradiol in granulosa cells
FSH
what hormone acts on theca cells and what does it do
LH and it increases steroid synthesis and synthesis of FSH receptor to magnify FSH response
role of progesterone in steroidogenesis
cross roads. can be made into glucocorticoids in adrenal glands and also act in testes and ovaries to make testosterone and estrogen
estrogen and progesterone act with what receptors
nuclear hormone receptors in the same way that glucocort. do
two isoforms of estrogen receptors
alpha and beta
true or false? there are more selective estrogen receptor ligands and modulators that act differentially with ERalpha or ERbeta
true
estrogen also acts on receptors where for implantation of fertilized oocyte
acts in endometrium so that cells there can proliferate and become more receptive to implantation
possible binding for both estrogen and progesterone to cell membrane receptors may cause what
nongenomic changes
oocyte is released where
into fallopian tube
how many ovulated oocyte per menstrual cycle
one
goal of contraception
prevent release or fertilization by sperm of ocyte
contraceptive drugs can also be used for…
for ovulation induction
hormone replacement therapy use
decrease in estrogens and progesterones leading to menopause
chemical analogs of progesterone and estrogen can also be used for…
cancer chemotherapy
most effective contraceptives
implants, IUD, sterilization
higher risks of pregnancy are with what contrceptives
male and female condoms, withdrawal
what peak triggers follicle rupture and ovulation
LH peak
estrogen peaks where
during follicle rupture
progesterone peaks when
after ovulation, mature corpus luteum
ovulation happens when during cycle
mid cycle
what degenerates and produces steroids when woman not pregnant
corpus luteum
if woman becomes pregnant what happens to uterine endometrium
hormones prepare the endometrium lining. increases after ovulation. to create a favorable environment for fertilized zygote to implant
what creates menstruation
degeneration of endometrium lining
positive feedback of HPO axis
increase in estradiol above a certain threshold stimulates GnRH and LH release which stimulates oocyte release
negative feedback of HPO axis
constant release of estradiol and progesterone prevents LH and FSH release
measuring temperature and detecting ovulation with thermometer method
fertility awareness based method
in fertile woman temperature increase because of what
progesterone release after ovulation
oral contraceptives contain what
analogs of estrogen and progesterone
why use analogs in contraceptive pills
because they have longer half lives
contraceptive pills use to be monophasic meaning?
each tablet contained a fixed amount of estrogen and progestin
contraceptive pills are now multiphasic meaning?
concentration vary during the cycle to try to mimic natural hormones
how is release of oocyte prevented and LH surge prevented and FSH
constant low amounts of estrogen given to prevent cycling. constant negative feedback
contraceptive effect on fsh
no fsh stimulation of follicle maturation in ovary
contraceptive effect of sperm
less able to swim to oocyte by changing composition of the protein the sperm has to swim. decreased fertilization
perfect use failure rate of contraceptive vs typical failure rate
0.3% vs 9%
failure of pill contraceptive is related to what
poor compliance like forgetting pill
metabolism of analogs
metabolized in the liver and gets conjugated to be released in GI tract.
Deconjugated by bacteria so that it can be reabsorbed in liver and released on circulation
problems with taking some antibiotics with contraception
antibiotic alters enterohepatic circulation such that they kill bacteria that would help remove congugated compound in drug and allow it to get reabsorbed. But antibiotics makes no reabsorption and drug excreted so no recycling of estrogen and progesterone, lower levels and cause normal cycle to come back
advantages of oral contraceptive (6)
- periods more regular
- can be used by women over 40
- may decrease menstrual cramps, acne
- does not interfere with sexual intercourse
- reduces risk of ovarian cancer
- increases bone density
disadvantages of oral contraceptives (3)
- increase risk of blood clots
- my by related to slight increase in breast cancer
- cant be used by smokers over the age of 35
risk of oral contraceptives relating to others
very low risk compared to others
contraceptive patch Evra mechanism
steroids penetrate the skin and into circulation so they cana be delivered to the hypothalamus and other tissues
pearl index of patch
0.88 so better than pill. half the rate of pregnancy in women after 6 cycles of taking the pill
compounds in patch
150 microg NGMN and 20 microg EE
contraceptive implants effectiveness
99%
IUD mechanism and types
inserted in uterus. Copper T delivers copper and progstin iud delivers progesterone
common analog of progesterone
levonorgestrol
emergency contraceptive and mechanism
plan b: levonorgesterol.
temporary block of ovulation
when should we take plan b
within 72 hours of unprotected sex
effectiveness of plan b
75-97% depending on time after intercourse
selective progesterone receptor modulator and is a partial antagonist and agonist
ulipristal acetate
ulipristal acetate efficacy and days
similar to that of progestin. effective for up to 5 days after intercourse
what drugs interact with contraceptive by inducing p450s and how
barbiturates, phenytoin (anti-epileptics), rifampicin. Contraceptives get metabolized by p450s that have been induced by these drugs
why should the pill not be taken for smokers over 35
increased mortality in smokers who take the pill after the age of 35 even more at 45 compared to smokers who are younger
patch compliance vs pill compliance
more compliance in patch and is not affected by age
more compliance in pill for older people, less compliance in younger people
implants contraceptives most contain what
progesterone analog levonorgestrel
