KA2.3 The biology of controlling Fertility Flashcards
What is male fertilise periods called
continuously fertile
What is female fertilise period called
Cyclical fertile
Why do men have continuous fertility
Due to negative feedback control of testosterone maintains level of FSH AND ICSH
Why do women have cyclical fertility
Pituitary and ovarian hormones cause short time of fertility
How can the female fertile period be calculated
- Temperature rise
- Thin, Watery cervical mucus
How much does the women’s body temperature rise by and how
0.5c due to progesterone
How does the women’s cervical mucus change
Due to progesterone to allow sperm easier access to oviducts
What is the stimulating ovulation
Treatment for infertility, women may fail to ovulate because of failure to secrete FSH AND LH
How can be ovulation stimulation
- Drugs preventing negative feedback of oestrogen on FSH secretion
- Drugs that mimic FSH AND LH
How effective are ovulation stimulating drugs
They bring out super ovulation which can result in multiple births or used to collect ova
What is Artificial insemination
If man has low sperm count, several samples are collected over few days to increase number of sperm then injected into women’s cervix
what is ICSI
if sperm are defective or low, intracytoplamsic injections, involves drawing head of sperm and injecting it into egg
What is IVF
Treatment to solve infertility caused by blockage of oviducts
What are the steps in IVF
- woman give hormonal treatment to stimulate “super ovulation
- removal of egg
- egg mixed with sperm in culture dish
- zygotes incubated for 2-3 days to allow cell division to form embryos
*2 or 3 embryos choose then Inserted into uterus - remaining embryos frozen and stored in case of second attempt is required
What is Pre-genetic Diagnosis
prior to implantation 1 or 2 cells removed and tested for a known chromosomal abnormalities or single gene disorders
How does PGD help medical staff
Identify embryos which should and should not be allowed to become implanted in endometrium
What is contraception
is an intentional prevention of contraception or pregnancy by natural or artificial means
What are the advantages of condoms
- Prevention STIs
*No prescription
*No hormonal side effects
*may decrease incidence of cervical cancer
Disadvantages of condoms
*Can burst
*possible allergic reaction
*decreased sensation
Advantages of diaphragm & Cap
*can be inserted 2 hours before intercourse
*Comfortable
*doesn’t alter menstrual cycle
*Doesn’t affect future fertility
Disadvantages of diaphragm & cap
*No protection against STIs
*Possible allergic reaction
*Requires fitting at clinic
*Risk of UTI
Advantages of IUD
*doesn’t require daily attention
* Immediately effective
*Long Lasting
Disadvantages of IUD
*No protection against STIs
*Required visit clinic
*Difficult menstruation
*risk of infection
*risk to future fertility
Advantages of sterilisation
*permanent
*Immediately effective (female)
*no daily attention
Disadvantages of sterilisation
*no protection against STI
*Requires surgery- risk
*not reversible
*not immediately effective (males)
How does the pill containing combination of hormones work
contains synthetic oestrogen and Progesterone that mimics negative feedback
*release of FSH and LH by pituitary is inhibited
*Follicle maturation is inhibited
*Ovulation fails to occur
How does Emergency contraceptive pill work
contains high doses of progesterone and oestrogen to prevent ovulation and implantation
How does progesterone only pill work
Contains synthetic progesterone to thicken cervical mucus
