1B4 Human Reproduction www.juniorscience.ie

OB33 understand the following in relation to human reproduction: OB31 use wall charts or other illustrative diagrams to identify and locate the main parts of the male and female reproductive systems OB32 recall that the menstrual cycle lasts about 28 days and that menstruation occurs at the start of the cycle OB33 understand the following in relation to human reproduction: • fertile period in the menstrual cycle • sexual intercourse • fertilisation is the fusion between male and female gametes (sperm and egg) resulting in a zygote; a zygote undergoes cell division and develops within the womb into a foetus • pregnancy and birth • growth and puberty OB34 understand that there are many forms of contraception, and that some of these prevent fertilisation www.juniorscience.ie

The male reproductive system The male reproduction system produces and delivers the male gamete (sperm) link to interactive diagram at Kid’sHealth Seminal Vesicle Sperm Duct Side view www.juniorscience.ie

The female reproductive system link to interactive diagram at Kid’sHealth The female reproduction system produces the female gamete (egg) and protects the developing embryo / foetus www.juniorscience.ie

Growth & Puberty Growth is a characteristic of all living things During puberty the reproductive systems mature After puberty a human is called an adult link to animation at bbc.co.uk www.juniorscience.ie

The menstrual cycle 28 day cycle in the female link to animation 28 day cycle in the female Controlled by chemicals called hormones An egg is produced, and the womb develops a thick lining of blood vessels to be prepared for pregnancy If the egg is not fertilised, the lining leaves the womb – menstruation – and the cycle begins again www.juniorscience.ie

Stages in the menstrual cycle 28 day cycle Approx. days 1 - 5 Menstruation – loss of uterus lining and unfertilised egg 5 - 13 Repair of uterus lining 14 Release of egg from ovary 14 - 28 Build up of lining of uterus www.juniorscience.ie

Fertile period in the menstrual cycle The egg is, usually, released around Day 14 of a 28 day cycle Fertilisation is possible for several days around this time www.juniorscience.ie

link to ‘how stuff works’ animation Sexual intercourse The natural process of transferring the sperm from the body of a male to the body of a female Millions of sperm are transferred in a fluid called semen…they immediately begin swimming towards the single egg cell link to ‘how stuff works’ animation www.juniorscience.ie

Fertilisation Occurs when a male gamete (sperm) fuses with the female gamete (egg) to form a zygote Also referred to as conception Sperm + egg = zygote www.juniorscience.ie

Fertilisation Fertilisation usually happens in the oviduct / fallopian tube A fertilised egg – zygote - may then move down into the wall of the uterus / womb www.juniorscience.ie

Pregnancy a zygote undergoes cell division and develops within the womb into a foetus over 40 weeks the foetus develops all its human features It develops inside a protective sac of fluid It receives food via a blood supply in the placenta link to animation www.juniorscience.ie

Birth Link to birth animation After about 40 weeks, when the baby is fully developed, the following happens: The sac of protective fluid breaks open The muscles of the uterus / womb contract very strongly to push the baby out After the baby is born, the placenta is also pushed out of the womb The umbilical cord between baby and placenta is cut Links to an animation – may be slow to load… www.juniorscience.ie

Contraception Main methods of preventing conception: Chemical - prevention of gamete formation e.g. the Pill Physical barrier – preventing the gametes from meeting e.g. condom Timing – avoiding sexual intercourse during the fertile period of the menstrual cycle www.juniorscience.ie

Find the answers: Why are human babies born so “helpless” compared to some animal babies? Why are human babies’ heads so big in comparison to their bodies? What are conjoined twins and how do they occur? What is foetal alcohol syndrome ? www.juniorscience.ie

1B4 Human Reproduction www.juniorscience.ie