1. The Circulatory System
The circulatory system is the body’s own transport system that carries substances around the body. It’s most important job is to carry oxygen and nutrients to all the cells in the body, and to remove waste from those cells.
heart
blood vessels
blood

2. The Circulatory System
The circulatory system carries two types of blood:
oxygen-rich blood
oxygen-poor blood
blood travelling
to the body cells
high oxygen content
low carbon dioxide content
blood travelling
away from the body cells
low oxygen content
high carbon dioxide content

3. The Heart
The organ at the centre of the circulatory system. It pumps blood around the body.

4. The Heart right side of the heart oxygen-rich blood left side
The inside of the heart is divided into two sections so that the two types of blood (oxygen-rich and oxygen-poor)
are kept apart.
right side
of the heart
oxygen-rich
blood
left side
of the heart
oxygen-poor
blood

5. The Heart and Lungs lungs lungs body’s cells
Blood is pumped around the body by the heart.
It takes about 30 seconds for blood to go once around the body.
The left side of the heart pumps oxygen-rich blood to the rest of the body.
Blood picks up carbon dioxide from the body’s cells.
This oxygen-poor blood then travels back to the right side of the heart.
Next, the right side of the heart pumps oxygen-poor blood to the lungs.
In the lungs the blood gets rid of the waste carbon dioxide and collects more oxygen.
The oxygen-rich blood then returns to the left side of the heart.
lungs
lungs
body’s
cells

6. The Chambers of the Heart
Each section of the heart is called a chamber. There are 4.
An upper chamber is called an atrium (plural atria).
A lower chamber is called a ventricle.
right
atrium
left
atrium
right
ventricle
left
ventricle

7. The Chambers of the Heart
The chambers of the heart have different functions.
Pulmonary artery - blood to the lungs
Aorta - blood to
the body
Pulmonary vein - blood from the lungs
Superior Vena Cava - blood from the body
The atria collect blood that enters the heart.
The ventricles pump blood out of the heart.

8. Heart valves
Blood always flows in the same direction as it moves through the heart during each circulation of the body.
The chambers of the heart are separated by valves which prevent blood from flowing in the wrong direction.
Pulmonary Valve - valve leading out of
right ventricle
Aortic Valve - valve leading out of
left ventricle
Tricuspid Valve - valve between
right atrium and right ventricle
Mitral Valve - valve between
left atrium and left ventricle

9. Heart dissection