Unit 2 - The biology of controlling fertility Key Area 3 Flashcards
Identification of the fertile period.
A woman’s body temperature rises by around 0·5°C after ovulation and her cervical mucus becomes thin and watery.
Explain difference between men and female fertile periods
Women show cyclical fertility leading to a fertile period. Men show continuous fertility.
Women are only fertile for a few days during each menstrual cycle. Men continually produce sperm in their testes so show continuous fertility.
State 2 ways that ovulation may be stimulated
Ovulation is stimulated by drugs that prevent the negative feedback effect of oestrogen on FSH secretion.
Other ovulatory drugs mimic the action of FSH and LH
What is ‘super Ovulation’
These drugs can cause super ovulation that can result in multiple births or be used to collect ova for in vitro fertilisation (IVF) programmes
A) What is Artificial Insemination
B) When is it used
C) When else can it be used
A) Several samples of semen are collected over a period of time.
B) Artificial insemination is particularly useful where the male has a low sperm count.
B) If a partner is sterile a donor may be used to provide semen.
A) When is Intra-cytoplasmic sperm injection (ICSI) used?
B) What is Intra-cytoplasmic sperm injection (ICSI)
A) If mature sperm are defective or very low in number, ICSI can be used.
B) The head of the sperm is drawn into a needle and injected directly into the egg to achieve fertilisation
Bullet point about In vitro fertilisation (IVF)
- Surgical removal of eggs from ovaries after hormone stimulation.
- Incubation of zygotes and uterine implantation.
- The use of IVF in conjunction with pre-implantation genetic diagnosis (PGD) to identify single gene disorders and chromosomal abnormalities.
What happens during Intro Vitro Fertilisation?
Eggs are mixed with sperm in a culture dish. The fertilised eggs are incubated until they have formed at least eight cells and are then transferred to the uterus for implantation
What is an oral contraceptive pill and what does it do?
The oral contraceptive pill is a chemical method of contraception. It contains a combination of synthetic oestrogen and progesterone that mimics negative feedback preventing the release of FSH and LH from the pituitary gland.
What does the progesterone-only ( mini ) pill do?
The progesterone-only (mini) pill causes thickening of the cervical mucus
What do Emergency hormonal contraceptive pills do?
When to take Emergency hormonal contraceptive pills and what they do?
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
What is contraception?
Contraception is the intentional prevention of conception or pregnancy by natural or artificial mean
What are examples of physical barriers which the ability of sperm to reach the ovum?
Physical barriers which block the ability of sperm to reach an ovum include:- Examples:- • Condom • Diaphragm • Cervical cap
What is an Intra-uterine device (IUD)
Intra-uterine device (IUD)
T shaped structure that is fitted into the uterus for many months or even years to prevent implantation of an embryo.
What is the sterile procedure called in males and females. Describe them both.
Sterilisation procedures
In men, a vasectomy involves cutting and tying the two sperm ducts. This prevents sperm being released during sexual activity
In women, a tubal ligation involves cutting and tying the two oviducts. This prevents eggs meeting sperm and reaching the uterus
