KA3- The Biology Of Controlling Fertility Flashcards
The biology of controlling fertility
Infertility treatments and contraception are based on the biology of fertility
Cyclical fertility
Women show cyclical fertility leading to a fertile period.
Women are only fertile for a few days during each menstrual cycle.
Continuous fertility
Negative feedback control of testosterone maintains a relatively constant level of pituitary hormones FSH and ICSH in the bloodstream so
Men continually produce sperm in their testes so show continous fertility
Identification of the fertile period (females)
A woman’s body temperature rises by around 0.5C after ovulation (remains elevated in luteal phase) and her cervical mucus becomes thin and watery
Chemicals methods of contraception
The oral contraceptive pill
The progesterone-only (mini) pill
Emergency hormonal contraceptive pills
The oral contraceptive pill
It contains a combination of synthetic oestrogen and progesterone that mimics negative feedback preventing the release of FSH and LH from the pituitary gland.
Progesterone only (mini) pill
Causes thickening of the cervical mucus
Emergency hormonal contraceptive pills
prevent or delay ovulation.
These pills are often referred to as ‘morning after’ pills, but they can be taken up to 72 hours or 120 hours after unprotected sex, depending on which type of pill is used.
Physical methods (barrier)
Prevent sperm from entering female reproductive system, fertilising ovum and fertilisation
Condom- rubber sheath over penis
Diaphragm- cap inserted in vagina to block cervix
Cervical cap- over cervix,
Physical method (non-barrier)
Intra-Uterine Device (IUD)
T shape in uterus, prevents implantation so fertilised eggs can’t develop
Physical methods (sterilisation)
Vasectomy- cutting and tying sperm ducts, prevents sperm release
Tubal ligation- cutting and tying oviducts, prevent sperm meeting ovum
