BLOOD CIRCULATION

Blood is continuously moving inside our body.
This movement is called blood circulation: it's the process by which blood flows to distribute oxygen and nutrients to different parts of the body and carries away waste substances.
The circulatory system is formed by:

• Blood: a red liquid which transports substances throughout the body.
• Blood vessels: arteries, veins and capillaries.
• The heart: an organ made up of muscles that are working all the time. The heart is connected to the blood vessels and pumps blood through them to all parts of the body.

CIRCULATORY SYSTEM. FROM WIKIPEDIA

BLOOD VESSELS

Blood vessels are hollow tubes that are distributed throughout our body and circulate blood.
An adult's body has abot four to six litres of blood in this closed circuit.
There are three types of blood vessels:

• Arteries are thick. Arteries carry blood away from the heart to other organs.
• Veins are thick. Veins carry blood back to the heart.
• Capillaries connect veins and arteries. They are thin and fragile.

There are three types of blood vessels.

THE RESPIRATORY SYSTEM

• When we breathe in, air enters the body through the nose or mouth.
• Then it travels down a long tube called the trachea.
• It continues through two pipes called the bronchi to the lungs.
• The lungs are the most important organs of the respiratory system. Here, oxygen passes from the air into the blood.
• Finally, we breathe out to expel carbon dioxide.

WE NEED AIR

We need oxygen to live.
Breathing is when our bodies obtain oxygen from the air and release carbon dioxide.
The respiratory system is the group of organs that carry out the function of breathing.

THE DIGESTIVE SYSTEM

The digestive system is a long tube that starts in the mouth and ends in the anus.

• Digestion begins when we chew food in our mouth and mix it with saliva.
• This mixture goes down the oesophagus to the stomach.
• In the stomach, it mixes with gastric juices.
• Next, the mixture passes into the small intestine. Nutrients are absorbed and pass into the blood.
• Undigested food and waste continue on to the large intestine, where water is absorbed and faeces are formed.
• Faeces are excreted through the anus.

THE DIGESTIVE SYSTEM

Click on the image to practice and learn.

THE DIGESTIVE PROCESS

We need to take in food for our body to function.
Food travels through the different organs of the digestive system.
It is broken down into small parts called nutrients that our body can absorb.
Digestion is the process that enables us to obtain nutrients from the food we eat: nutrients pass into the blood.
Waste and undigested food are excreted from the body as faeces.

Food. From Wikipedia

OUTSIDE - INSIDE YOUR BODY

OUTSIDE YOUR BODY
The main parts of your body are the head, the trunk and the limbs.
The trunk is divided into two parts: the thorax and the abdomen.
Here you have a link to see what we studied last year about this.


INSIDE YOUR BODY
There are different organs inside your body to make it work.
Some organs are the muscles, the bones, the brain, the heart and the lungs.
And here another link.

FREEDIVING

Did you know that people breathe between 12 and 20 times every minute?
Most people need to take in air at least every 30 or 40 seconds.
Freediving is a watersport that consists of holding your breath while diving underwater to great depths.
It is a highly dangerous sport and an extreme test of lung capacity.
Freediving needs special training.
Herbert Nitsch is an Austrian freediver who set the current world record for freediving.
In 2007 he dived to the incredible depth of 214 metres.
He didn't breathe in air for four minutes!

Here you have the video of that record:


And here you have William Trubridge's World Record Freediving without fins:


And here you have Ashley Chapman's World Record Freediving without fins (women):