Lesson video

Hello, everyone.

How are you today?

I hope you're feeling good.

My name is Ms. Atsal, and I'll be your teacher for this lesson.

I'm feeling pleased about that because we've got a pretty interesting topic ahead.

We're looking at gestation and birth.

I wonder how much you already know about this topic, and I hope you're interested in it.

A lesson is called Gestation and Birth in Humans, and it comes from the unit of work, reproduction in humans.

So if you're ready to explore this topic, if you have some energy, focus, and enthusiasm, we'll begin our lesson now.

The outcome for today's lesson is, I can describe the growth of a foetus and the process of giving birth.

I hope that sounds interesting to you.

We have some keywords in our lesson.

I'd like us to go through them one at a time, saying them out loud.

My turn, your turn.

Foetus, placenta, umbilical cord, amniotic sac, contractions.

Good to hear those keywords out loud.

Pause here and share with someone.

Have you heard of any of these keywords before?

Do you have an idea of what any of these keywords mean?

Share with someone nearby.

Thanks for sharing.

Let's find out what these keywords mean.

The foetus is the stage of human development between an embryo at around eight weeks up to when the baby is born.

The placenta is an organ that is attached to the uterus wall; it provides the foetus with oxygen and nutrients from the mother's blood.

The umbilical cord joins the placenta to the foetus; it carries the nutrients and oxygen needed.

The amniotic sac surrounds the foetus and contains fluid, which protects it.

Waves of muscle contractions in the uterus wall during childbirth push the baby down through the vagina.

These are our keywords, foetus, placenta, umbilical cord, amniotic sac, and contractions.

Let's look out and listen out for them.

They'll be coming up in our lesson today.

Today's lesson is called Gestation and Birth in Humans, and it has three learning cycles, gestation, the placenta, and birth.

Let's begin by exploring gestation.

During sexual reproduction in humans, fertilisation produces a single cell, a zygote, and there we have this fertilised egg cell.

This grows and develops in stages to make a baby.

We have the embryo and then a foetus not drawn to scale, and then the baby ready to be born.

After fertilisation in the fallopian tube, the zygote will divide to form a ball of identical cells called an embryo.

There we can see the zygote and the embryo.

The embryo will move down the fallopian tube and implant into the wall of the uterus.

And here we have the arrows showing the journey.

Zygote becomes the embryo and then moves down into the wall of the uterus.

The cells of the embryo start to take on different jobs.

Groups of cells form tissues that have different functions.

And then in three to four weeks, we have the foetus.

The tissues in the embryo develop to form organs, and the embryo becomes a foetus after around eight weeks.

In this diagram, we can see right in the center there is the foetus connected to the placenta by the umbilical cord, and it's within the amniotic sac.

The different cells and tissues allow the foetus to look and function more like a human.

As the foetus grows, it is protected by the uterus and the amniotic fluid, a liquid contained in a bag called the amniotic sac.

It's one of our keywords.

And here we can see a human foetus at 12 weeks.

And there it is protected by the amniotic fluid in the amniotic sac.

The gestation period is how long it takes for a foetus to become fully formed and ready for birth.

In a human, this is about 40 weeks from fertilisation.

And here we can see visually the changes taking place during the gestation period.

Let's have a check for understanding, true or false.

All cells that form the foetus are produced from the zygote.

Pause here and share with someone.

Is this statement true or false?

Well done if you said true.

And now I would like you to justify your answer by choosing from one of these two statements.

A, the zygote divides to form lots of the same type of cell to make up the foetus.

B, the zygote divides to form lots of cells which then change to form the different tissues that make up the foetus.

Pause here while you decide which of these statements justifies your earlier answer.

Well done if you selected statement B.

Indeed, the zygote divides to form lots of cells, which then change to form the different tissues that make up the foetus.

And now it's time for your first task.

I would like you to match the keyword to the correct definition.

Here are our keywords.

Embryo, foetus, zygote, amniotic sac.

And the definitions.

Fertilised egg cell formed in the fallopian tube.

Contains amniotic fluid to protect the foetus.

A ball of cells formed from the zygote dividing.

The growth stage after embryo and before birth.

Pause here while you match the keywords to their correct definitions.

I'll see you when you're finished.

So let's match the keywords to their correct definitions.

The embryo is a ball of cells formed from the zygote dividing.

Foetus is the growth stage after embryo and before birth.

Zygote is the fertilised egg cell formed in the fallopian tube.

And the amniotic sac contains amniotic fluid to protect the foetus.

Well done if you match the keywords and the definitions like this.

For the next part of your task, I would like you to label the diagram with the key structures involved in embryo growth.

Pause here while you have a go at this task.

So how did you get on with labeling the diagram with the key structures involved in embryo growth?

Did you label the foetus right there in the center?

The placenta, the umbilical cord connecting the foetus and placenta, the amniotic sac, which contains the amniotic fluid protecting the foetus.

Well done if you labeled the diagram in this way.

And now we're onto our next learning cycle, the placenta.

The foetus relies upon its mother as it develops.

These are some of the things it needs.

Protection against knocks, bumps, and temperature changes.

Oxygen for respiration.

Nutrients, food and water.

The developing foetus also needs its waste products removing.

So how does the foetus get these things that it needs?

Well, the placenta provides the oxygen and nutrients.

It also removes waste substances such as carbon dioxide.

The umbilical cord provides the nutrients and oxygen from the mother's blood in the placenta to the foetus.

An amniotic fluid, inside the amniotic sac provides protection against bumps and temperature changes.

A growing foetus does not eat or breathe.

Blood from the foetus and blood from the mother flow next to each other in the placenta, where substances are exchanged.

So here we can see the mother's blood vessels and the foetus' blood vessels.

Oxygen and nutrients pass from the mother's blood into the placenta.

So we can see the movement of the oxygen and nutrients.

And waste substances such as carbon dioxide pass from the foetus' blood into the placenta.

The mother's blood carries the waste products away.

The foetus' blood travels along the umbilical cord to the foetus to deliver the oxygen and nutrients.

Let's have a check for understanding.

Choose two correct descriptions of the role of the placenta.

A, protects the foetus from bumps.

B, provides the foetus with blood.

C, removes carbon dioxide.

D, provides oxygen and nutrients.

Pause here while you choose two correct descriptions of the role of the placenta.

Well done if you selected C, removes carbon dioxide and D, provides oxygen and nutrients.

These are two correct descriptions of the role of the placenta.

And now it's time for your next task.

Laura and Lucas are discussing the role of the placenta.

Here's Laura.

"The placenta is where the blood vessels of the mother and foetus are close, so that the mother can provide carbon dioxide and nutrients to the foetus.

" And here's Lucas.

"The placenta is the organ where the foetus and the mother's blood mix, and its substances are exchanged.

" Both pupils have made an incorrect statement in their response.

Identified a mistake each has made and correct it.

So pause here while you have a discussion about this and identify with their mistakes and correct their statements.

I'll see you when you're finished.

It's good to be back with you.

So how did you get on with identifying the mistakes that Laura and Lucas each made and correcting them?

Here's what Laura said.

"The placenta is where the blood vessels of the mother and foetus are close, so that the mother can provide carbon dioxide and nutrients to the foetus.

" And the correction is, the mother provides oxygen and nutrients, not carbon dioxide.

Carbon dioxide passes from the foetus' blood into the placenta and is taken away by the mother's blood.

And here was Lucas' statement.

"The placenta is the organ where the foetus and mother's blood mix, and substances are exchanged.

" And a correction is, that the blood vessels of the mother and foetus are close to each other, but the blood does not mix.

Well done if you identified the mistakes and made the corrections in this way.

Well done for having a go at this task.

And now we're onto our next learning cycle, birth.

The mother and the baby release hormones, chemicals, when it is time for birth to take place.

The cervix relaxes and the muscles in the wall of the uterus contract.

Waves of muscle contractions continue through labour and birth to push the baby out of the mother's body through the vagina.

So muscle contractions are taking place in the wall of the uterus.

The cervix opens, and the head comes down through the vagina first, and then the body of the baby follows.

Let's have a check for understanding.

Put these stages of birth in the correct order.

A, muscles in the wall of the uterus contract.

B, cervix opens.

C, baby is pushed out through the vagina.

D, hormones are released.

Pause here while you put these stages of birth in the correct order.

Well done if you ordered them in this way.

One, hormones are released.

Two, muscles in the wall of the uterus contract.

Three, cervix opens.

And four, the baby is pushed out through the vagina.

These are the stages of birth in the correct order.

And now it's time for your next task.

I would like you to label this diagram with the organs involved and a description of how they're involved in birth.

Pause here while you have a go at this task.

I'll see you when you're finished.

It's good to be back with you.

How did you get on with that task?

Labeling the diagram with the organs involved and a description of how they're involved in birth.

Here's the uterus.

The muscles in the walls contract to push the baby down into the vagina.

The vagina, the baby passes out of the mother through this muscular tube.

Cervix, hormones and muscle contractions cause it to open so the baby can pass from the uterus to the vagina.

Well done if you labeled the diagram and describe how these organs are involved in childbirth in this way.

Well done for having a go at this task.

In our lesson, gestation and birth in humans, we've covered the following.

A zygote divides to become an embryo in the fallopian tube, which then develops into a foetus made of different cells and tissues.

The foetus grows in an amniotic sac, which is filled with amniotic fluid for protection until it is ready for birth.

The human gestation period is about 40 weeks.

The mother provides all the nutrients and oxygen that the growing foetus needs and gets rid of waste products, through the placenta and umbilical cord.

During birth, hormones are released causing muscle contractions in the uterus and the cervix to open; this pushes the baby out through the vagina.

Well done everyone for having a go at this lesson and exploring the the incredible processes of gestation and birth in humans.

I thought it was so interesting to go from the zygote dividing to the entry of a baby into the world.

What an incredible process.

How remarkable what it took for each of us to be here now.

I really enjoyed teaching you, and I hope you enjoy this lesson and this learning, and I'm looking forward to seeing you at another lesson soon.

Until then, stay curious.