The story so far……..

The first stage in reproduction..

• Sexual Intercourse:

• Copulation

Humans have specially designed reproductive organs for copulation.Male Reproductive System

Prostate Gland

Produces the fluid which nourishes the sperm and allows them to swim

Testes

Produces and stores the sperm

Sperm Duct

Carries the sperm from the testes to the penis

Penis

Is placed inside the vagina where it deposits sperm

Female Reproductive System

Vagina

Entry point of the penis during copulation.

Cervix

Connects the uterus to the vagina

Uterus

Develops a spongy lining for the embryo to implant

Ovary

Stores and releases egg cells

Oviduct

Where fertilisation takes place. Embryo moves down towards uterus.

Route to Fertilisation

Ovary

Oviduct Uterus

11.

1. Egg is released from the ovary and picked up by the oviduct.

2

2.Egg is moved along oviduct by hair like cilia.

4.

3.

3. Sperm is deposited in the vagina and swims towards the egg up the oviduct.

4. Sperm and egg meet and FERTILISATION takes place.

After Fertilisation

Ovary

Oviduct Uterus1. 1. Fertilisation produces a Zygote.

2. The zygote divides in half to form an embryo.

2

3, The embryo continues to divide until it forms a ball of identical cells.

3

4

4. The embryo implants itself in the wall of the uterus where it continues to develop.

Once the embryo has implanted itself within the uterus the ball of cells begins to specialise into different

types of cells.• The embryo must not only develop into a

baby but it must also provide a way of catering for the developing babys needs.

What are these needs?

Food ProtectionExcrete Waste Products

Oxygen

Food, Oxygen and Excretion of waste

Supplying food and oxygen and the excretion of waste is the responsibility of

the placenta.

The placenta is a link between the mother and the developing embryo

The placenta is formed from part of the embryonic ball of cells

Placenta

Placenta

Foetus

Umbilical Cord

The Placenta is formed around two weeks after the embryo has implanted in the uterus.

A closer look

• Although very close together the maternal and foetal bloodstream do not mix.

Mother

Foetus

Foetal blood supplyMaternal Blood

Supply

FoodOxygen CO2 Waste

The required substances are able to pass from the mothers blood supply to the foetus and vice versa by DIFFUSION

Umbilical chord

PROTECTION• The developing foetus is vulnerable and needs

protection• This is provided by a fluid called amnion which is

enclosed in the amniotic sac.• Amniocentesis is a test performed on the amnion

which can detect chromosomal defects.

Embryonic Development 1st Month

SIZE: 0.5 cm

Features Formed: spine, nervous system kidneys, intestines,

Additional Notes: Day 21 heart starts beating , legs,arms eyes and ears are noticeable

Foetal Development 2nd Month

Size:1 cm.

Features Formed: Arms legs, fingers and toes.

Additional Notes: Recognisable as a human so it is a foetus Responds to touch and can feel pain. Can hear the amniotic fluid rushing by.

Foetal Development 3rd Month

Size: 5cm

Features Formed: vocal chords and brain fully formed

Additional Notes:Foetus can squint swallow frown and make a fist. The mother may a kick as it moves around

Foetal Development 5th Month

Size:30 cm

Features Formed: completely developed. Eyebrows and eyelashes. Sex organs formedAdditional notes: recognise voices, can jump in surprise.

Foetal Development 7th Month

Size:40 cm

Features Formed: fully developed

Additional notes: Foetus spends most of its time sleeping. Over the next two months it will grow to 3x its length and develop fat.

Gestation Period

The gestation period is the time from the implantation of the egg to the birth of the baby.

In humans it is approximately 9 months

Have a guess how long the gestation period is for a cat??

• 6o days gestation

Guess how long the gestation period is for this mouse?

• 12 days!!!!

Guess how long the gestation period is for an elephant?

• An elephant has the longest gestation period of 18- 22 months

The final stage of reproduction is the birth of the new individual

The baby decides when it is time to arrive and sends a message to the

mother.The placenta detaches from the mother and the baby begins its journey down the cervix.

The mother will feel contractions as the baby moves, this is the first sign of labour.

The amniotic sac will then burst releasing the fluid this is known as your waters breaking.

The baby will continue to move down through the cervix and out of the vagina

You are about to see the most amazing video clip

Look away if your squeemish

Congratulations you have survived the journey of

reproduction from start to end.

Wasn’t it AMAZING