1. The Reproductive System

2. What do I need to know?
The structure and function of the parts of the male and female reproductive system
The Menstrual Cycle
Sexual Intercourse
Fertilisation
Pregnancy
Birth – including growth of the baby
Contraception Methods

3. The male reproductive system
The male reproduction system produces and delivers the male gamete (sperm)
Seminal Vesicle
Sperm Duct
Side view

4. The Male Reproductive System Testis
The testis (Testes) makes sperm
They start to make sperm between the ages of 12 and 14 – Puberty
Sperm are the male sex cells (also called gametes)
Each sperm cell is tiny and they are produced in large numbers by the testes.

5. Scrotum The scrotum is a sac in which the testes are held
The scrotum allows the testes to be kept at a temperature just below body temperature – this allows sperms to be made successfully

6. Sperm Ducts Two sperm ducts carry sperm from the testes to the penis
A number of glands are located beside the sperm ducts
These glands produce a liquid called seminal fluid in which sperm are released
The combination of sperm and seminal fluid is called semen

7. Penis The sperm ducts join to form a tube called the urethra
Sperm pass through this tube, which is located in the centre of the penis
The penis allows semen (or sperm) to pass out of the male body and into the body of the female

8. The female reproductive system
Junior Science Website
The female reproduction system produces the female gamete (egg) and protects the developing embryo / foetus

9. Ovary The ovaries produce eggs
The ovaries start to make eggs at puberty
Eggs are the female sex cells or gametes
Each egg is larger than a sperm cell
Normally one egg is formed each month in the female body from puberty until about 50 years of age
At this stage, called the Menopause, the female stops forming eggs

10. Fallopian Tube & Uterus
The fallopian tube collects the egg from the ovary and carries it to the uterus
If sperm are present one of them may join with the egg in the fallopian tube.
If there are no sperm present the egg dies
UTERUS
The uterus or womb is the area in which a baby (or embryo) will develop

11. Cervix & Vagina The cervix is the opening or the neck of the uterus
Sperm pass through the cervix in order to reach an egg
Vagina
The vagina is a muscular tube into which the penis releases sperm
It forms the birth canal when the baby passes down the vagina at childbirth

12. 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

13. 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
Build up of lining of uterus

14. Days 1 - 5
The lining of the uterus (which had built up during the previous menstrual cycle) breaks down.
This lining along with some blood, is passed out of the body through the vagina
This process is called menstruation or having a period
During these days an egg matures in the ovary

15. Days 6 - 13 A new lining develops in the uterus
The lining will be needed to nourish a developing baby if the female becomes pregnant
The egg continues to develop in the ovary

16. Day 14 The egg is released from the ovary This is called ovulation
The egg can survive for two days in the fallopian tube
Ovulation is the release of an egg from the ovary

17. Day
The lining of the uterus remains in place until it breaks down on the first day of the next menstrual cycle

18. The Fertile Period
The fertile period is the days in the menstrual cycle when a female is most likely to become pregnant if she has intercourse
Sperm can stay alive in the female reproductive system for up to three days - this means that pregnancy can occur if the female has intercourse 3 days before ovulation
The egg can stay alive for 2 days after ovulation – this means that pregnancy can occur if the female has intercourse 2 days after ovulation

19. This means that the fertile period lasts from day 11 to day 16 in a typical menstrual cycle
Menstrual cycles can be longer or shorter in different females – the fertile period is different for every female
In some cycles the fertile period could start as early as day 8 or 9, while in other cycles it could last until day 18 or beyond

20. 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

21. 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
Sperm + egg = zygote

22. Path of the Sperm
Normally over 100 million sperm are released into the vagina
The sperm swim through the cervix and into the uterus
They can swim from the uterus towards the fallopian tube
If there is no egg present in the fallopian tube the sperm die within three days

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

24. 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

25. Birth
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

26. 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