B11.7 The artificial control of fertility Flashcards
What is contraception?
The prevention of the egg and sperm meeting or a fertilised egg in the uterus
How does the contraceptive pill work?
Use female hormones to prevent pregnancy. Contains low does of oestrogen along with some progesterone.
Hormones inhibit the production of FSH affecting the ovaries so no eggs mature preventing pregnancy
Also stope the uterus lining developing - preventing implantation
Also makes the mucus in the cervix thick to prevent sperm getting through
What are the issues with a contraceptive pill?
Raised blood pressure - breast cancer
What does the progesterone pill do?
Only contains progesterone - have fewer side effect but they must take the pill regularly - if they don’t the artificial hormone levels drop and their body’s own hormones can take over - can lead to an unexpected release of an egg
What is a contraceptive implant?
A tiny tube that is inserted under your skin and slowly releases progesterone - delivers hormone
What is the contraceptive patch?
Contains a mixture of oestrogen and progesterone
You stick the patch to your skin - replace it every 7 days and the hormones are absorbed directly into your blood stream - prevents egg maturing and being released
What are some chemical methods to reduce pregnancy?
Spermicides - kill or disable sperm
What is a condom?
A thin latex placed over the penis to collect the semen and prevent the egg and sperm meeting
Offer some protection against STD’s such as HIV/ AIDS
However can be damaged and let sperm through
What is a diaphragm/cap?
Thin rubber diaphragm placed over the cervix before sex to prevent the entry of sperm
Might allow sperm to get pas if the cap is not positioned properly
What are Intrauterine devices?
Small structures that are inserted into the uterus
Last for 3 -5 years
Prevents any early embryos implanting in the lining uterus if it contains copper
Other contains progesterone releasing it slowly to prevent the build up of the uterus lining and to thicken the mucus of the cervix
May cause period problems or infections
What is Absitnence?
If people do not have sex they will not get pregnant
What is the rhythm method?
Abstaining from intercourse around ovulation or when an egg is in the oviduct means sperm cannot fertilise the egg.
No side-effects but very unreliable
What are surgical methods?
People can be sterilised
In men the sperm ducts are cut and tied - prevent sperm getting into the semen - this is called vasectomy
In women oviducts are cut or tied to prevent the egg reaching the uterus
