Week 2- contraception Flashcards
(40 cards)
Describe the hypothalamic pituitary axis in relation to ovarian hormones?
Hypothalamus releases gonadotrophin releasing hormone which stimulates the anterior pituitary to release follicle stimulating hormone and luteinising hormone. this stimulates the ovaries to produce oestrogen and progesterone. Progesterone acts on the anterior pituitary via negative feedback, oestrogen acts on the hypothalamus via negative feedback.
What hormone spikes before ovulation?
LH
What does the release of follicle stimulating hormone have on the ovaries?
Causes the primary follicle to develop into the secondary follicle.
What do the ovaries release in response to follicle stimulating hormone?
Oestrogen
What effect does oestrogen have on the gonadal hormones?
In low concentrations- oestrogen inhibits LH
In high concentrations- it inhibits FSH.
Describe the follicular phase of menstruation?
GnRH is released causing the anterior pituitary to release FSH and LH. FSH causes the primary follicle to develop into the secondary follicle releasing oestrogen. The low levels of oestrogen suppress LH. As more oestrogen is produced it starts to inhibit FSH and LH levels spike. This spike causes ovulation.
Describe the luteal phase of menstruation
The oocyte has been released and the follicle is now dead. The LH dips again. The corpus luteum secretes several hormones as it is converted to the corpus albicans. These hormones are progesterone, oestrogen and inhibin. Progesterone inhibits GnRH release, oestrogen inhibits LH and inhibin prevents the release of FSH. Once it becomes the corpus albicans these hormones are no longer released and it becomes the corpus albicans.
How long do sperm last in the female reproductive tract?
5 days.
How long does the ovum survive for?
17-24 hours.
What is meant by pearl index?
Number of contraceptive failures per 100 women/year
What is meant by basal body temperature?
Temperature your body is at when you wake up in the morning.
What happens to the basal body temperature at ovulation?
It rises by above 0.2 degrees and is sustained.
At ovulation, what happens to the cervical mucous? What is the purpose of this?
It becomes thin and watery, to allow sperm to swim easier.
What position is the cervix in when a woman is fertile?
High in the vagina, soft and open.
What position is the cervix in when a women is not fertile?
Low in the vagina, firm and closed.
In a 28 day cycle, what day is the women most fertile?
8-18.
Is breastfeeding an effective contraception?
Yes- but you have to do it under certain conditions.
- exclusively breast feeding
- Amenorrhoeic
- Less than 6/12 post natal.
Give an example of IUS contraceptives and what does IUS mean?
Intra-uterine system- examples are the mirena coil and the Jaydess.
Give an example of IUD contraceptives and what does IUD mean?
Intra-uterine device- copper coil.
How does the combined oral contraceptive pill stop pregnancy?
What co-effects does it also have?
It secretes oestrogen and progesterone. Progesterone inhibits the release of FSH and LH and oestrogen inhibits the release of GnRH.
This means it inhibits ovulation.
It also makes cervical mucous more sticky and thick.
What is the pearl index for the combined OCP?
0.3%
What is the mode of action of the progesterone only pill?
What co-effects does it have?
It inhibits ovulation by secreting progesterone. This stops the pituitary from releasing FSH and LH.
-It thickens cervical mucous
-It effects Fallopian tube transport of the egg
It also effects the endometrium.
What differs between the newer and older POPs?
Older ones don’t inhibit ovulation.
Give an example of progesterone only pills?
Desogestel
