You were once big enough to fit in the head of a pin.

Once you were born your hand was barley big enough to wrap around an adult thumb.

How did you go from the size of pin head to the size of a baby?

Development of Foetus

You may have heard you grow in your mother tummy. However this is totally wrong, you don’t grow in the stomach you grow in the Uterus.

The time from an embryo to a baby, 9 months later is called gestation.

During pregnancy a lot of thing can go wrong. The cells are specialising and becoming arms, legs, muscles, skin, neurons, eyes, heart etc…

It is very important not to smoke, drink or take drugs during pregnancy. The effects can be disastrous on the baby.  

Smoking, drugs and alcohol can cause the baby to become addicted to drugs, physical abnormalities, brain abnormalities, learning difficulties and even death.

After 8 weeks of growth the embryo become a Fetus. The fetus continue to grow in the uterus.

The uterus expands to accommodate for the growing baby.

As you can imagine growing so much requires a lot of energy. While you were in your mother womb you still needed nutrients and oxygen. Your mother supplied you everything you needed to survive through her blood.

Everything your mother ate and breathed you did too.

Quick Questions

1. Define the term Gestation

2. How long until an embryo becomes a foetus?

3. Why is it bad to smoke, drink and try drugs when pregnant?

Within the uterus there are 3 main structures.

Placenta - this is an organ where substances pass between the mother’s blood and the fetus’s blood.

Although the blood doesn't mix, nutrients and oxygen diffuses from the mother to the fetus, and waste (Co2) diffuses from the fetus to the mother.

It also acts as a barrier stopping infections and harmful substances from reaching the fetus.

Umbilical cord - A cored which connects the fetus to the placenta. This is why you have a belly button.

Fluid sac - A shock absorber, protecting the fetus from any knocks. This is filled with amniotic fluid.

In the womb you go through some amazing changes. Scroll over mouths 1, 2 and 3 too see the changes.

When roughly 40 weeks is up, the baby is ready to be born.

The cervix relax, the muscles of the uterus wall contract and gradually push the baby out through the vagina.

When the baby is born it is still connected to the mother by the umbilical cord. The placenta is push out.

Quick Questions

1. What are the three main structures within the uterus.

2. What is the role of the placenta?

3. How does the umbilical cord and placenta work together to help the baby survive.

Questions

The video bellow demonstrates the development of the baby from embryo to fetus

Short Answer Questions

1. Copy and Complete the sentence

A _______ develops in the _________ . This is know as _________ . The ______ protect the fetus from bumps. The fetus is attached to the placenta by the ________. Substances transfer between the mother and baby through their ___________ in the placenta. After ________ weeks the baby is ready to be born.

2. Describe how substances are transferred between a mother and her fetus.

3. What are contractions?

4. What are the steps involved in giving birth

Extension

5. Explain how the uterus supports the development of the baby.

6. Research task - Describe the development of the arm and leg in a fetus.  

7. Research task - Choose one of the following, and research the effects they can have on the development of the fetus.

i. Alcohol

ii. Heroin

iii. Smoking