Circulatory System

THE HEART

The heart is a muscle. The human heart is about the size of a

clenched fist. The heart pumps blood throughout the

body. The heart is made up of four chambers.

Heart facts

Red cells made in bone marrow carry haemoglobin which contains iron which

carries oxygen White cells

Bigger than red cells Less common Help get rid of viruses

Plasma Are broken up blood cells Help with blood clotting

Platelets Made up of mostly water Helps regulate body temperature

What is blood made up of?

3 main jobs: Carries water, oxygen and nutrients. Removes waste materials Maintains body temperature

What does blood do?

http://www.youtube.com/watch?v=D3ZDJgFDdk0

http://www.youtube.com/watch?v=H04d3rJCLCE

How the heart works

This is a mammals circulatory system

Right Ventricle Right atrium Left Ventricle Left Atrium Pulmonary artery Aorta Valves

What are these?

But not all animals are the

same

Different circulatory systems

Differences between systems Fish Blood passes through the

heart once in a circuit of the body

Have a 2 chambered heart

Mammals - blood passes through the heart twice in one circuit of the body - have a 4 chambered heart

Only have one ventricle so blue and red blood can mix

So a 3 chambered heart

One other difference