A – The reproductive system The structure and function of reproductive organs and gametes and their role in fertilisation Hormonal control of reproduction The biology of controlling fertility Ante- and postnatal screening

KA 3: The Biology of Controlling Fertility (a) Basis of controlling fertility (d) Contraception (b) Fertile Periods (c) Treatments for infertility

(d) Contraception State the 2 methods of contraception Give examples of each method of contraception Describe the biological basis for each method of contraception.

Contraception Quiz: Read and Relate! In your groups, select a ‘runner’ This person is in charge of collecting a question at a time, writing the answer down and returning it to me! Everyone else must read through the information and find the answer as quick as possible! RULE: you cannot collect a new question if your previous answer is wrong! Or you can just make them write if you want??

(usually involving hormones) Physical (stops gametes from meeting) (d) Contraception The intentional prevention of conception or pregnancy by natural or artificial means. Chemical (usually involving hormones) Physical (stops gametes from meeting)

Intrauterine Devices (IUD)

Sterilisation procedures in males

Sterilisation procedures in females

Contraception 1 Physical methods Avoiding sexual intercourse during fertile periods Barrier methods physically block the ability of sperm to reach an ovum (condom, diaphragm, cervical cap) Intra-uterine devices (IUD) are fitted into the uterus (for months or years) and prevent the implantation of an embryo in the endometrium Sterilisation procedures in males involves a vasectomy. This involves cutting and tying 2 sperm ducts, therefore preventing the release of sperm during intercourse Sterilisation procedures in females involves cutting and tying 2 oviducts to prevent eggs from reaching the sperm

Oral contraceptive pills Morning After Pill Mini Pill

Contraception 2 Chemical methods Chemical contraceptive pills are based on a combination of synthetic (man-made) hormones that mimic negative feedback preventing the release of FSH / LH Oral contraceptive pills normally contain synthetic progesterone combined with synthetic oestrogen. These pills are taken for 3 weeks in order to increase the progesterone levels and therefore inhibit the production of FSH and LH there by preventing the development and maturation of a follicle ‘Morning after’ pills are emergency contraceptive pills since they contain higher doses of the hormones. They are taken after intercourse to prevent implantation of a fertilised egg ‘Mini-pills’ are also known as Progesterone Only Pills. They work by causing thickening of cervical mucus, therefore reducing the sperm’s viability and their access to the uterus