The Heart and the Blood.
Why are they important?
The Circulatory System
• This is the
circulatory system of
the human body.
• Arteries are shown
in red, veins in blue.
The heart is in the
middle of the chest.
• Here are three types
of blood cells viewed
under a scanning
• You can see red
blood cells, white
blood cells and,
shown in blue,
• The heart is a muscle.
• It pumps blood around the body.
• Your heart is about the size and shape of
• Blood is the body's delivery and collection
• It delivers food and oxygen to every part of
the body, and it collects waste products,
particularly carbon dioxide.
• Blood circulates, or goes round and round
your body, about 2000 times a day. It is
pumped by the heart through tubes called
Inside the Heart
• When a heart is cut open, you can see a thick
wall down the middle, dividing it up into two
halves – a left and a right side.
• The heart is really two pumps working side by
side. Each pump has a top space, or atrium,
which receives blood from the veins. Below
each atrium is another space, a ventricle,
which pumps blood out of the heart and into
The Structure of the Heart