Download blood

Circulatory
System
The Circulatory System
• The circulatory, or
cardiovascular, system
is made up of the
heart, blood vessels,
and blood.
• In one day, human
hearts beat about
100,000 times and
pump around 1,500
gallons of blood!
Whew!
I’m tired!
What does it do for us?
Our circulatory system…
• Delivers necessary
materials (like oxygen
and sugar) to the entire
body in the blood,
• Removes waste products
from cells, and
• Helps fight disease by
transporting immune
cells in the blood.
How does it move stuff?
•
•
•
The circulatory system is like a
system of roads that links your
entire body
The “roads” are blood vessels –
some are like superhighways,
and others are like small onelane paths.
Your blood travels on these
roads like a “mail man” – it both
delivers and picks up important
materials.
How does it move stuff?
•
Your blood travels
in two main loops:
1. From the heart to
the lungs and back,
and
2. From the heart to
the body and back.
How does it move stuff?
Basically, your blood follows this cycle:
Blood gets rid of carbon
dioxide and picks up oxygen.
Blood enters
the right side
of the heart
and is pumped
out again.
Blood enters
the left side
of the heart
and is pumped
out again.
Blood delivers oxygen to body and
picks up waste (like carbon dioxide).
Oxygenpoor blood
from the
body
enters the
right side
of the
heart and
is pumped
out to the
lungs.
Oxygenrich blood
from the
lungs
enters the
left side
of the
heart and
is pumped
out to the
body.
How does it move stuff?
•
Your heart is the pump that
sends the blood through
the system.
RIGHT
•ATRIUM
The heart is a hollow,
muscular
organ.
RIGHT
VENTRICLE
LEFT
ATRIUM
LEFT
VENTRICLE
•Inside the heart, there are four main
chambers: two atria (right and left) and
two ventricles (right and left).
What’s inside your heart?
SEPTUM
•The right and left sides of the heart are
separated by a wall of tissue called the
septum.
What’s inside your heart?
VALVE
VALVE
ventricles
are separated
by
•The atria and
receive
the incoming
blood, and
valves,
which prevent
fromeither
flowing
the
ventricles
pump itblood
back out,
toin
wrongor
direction.
the lungs
to the body.
• From Body
So, the detailed path of blood in
your body would look like this:
• Right Atrium
• Right Ventricle
• To Lungs
• From Lung
• Left Atrium
• Left Ventricle
• To Body
Lung
Body
What’s inside your heart?
•The ventricles are in charge of pumping the
•This is a real sheep heart. Look at how
blood out to the entire body. They need to
thick the walls of the ventricles are. Why is
be thick and strong to have enough force!
this?
Heart Facts
• Hold out your hand and make a fist. If you're a kid, your
heart is about the same size as your fist, and if you're an
adult, it's about the same size as two fists.
• Your heart beats about 100,000 times in one day and
about 35 million times in a year. During an average
lifetime, the human heart will beat more than 2.5 billion
times.
• Give a tennis ball a good, hard squeeze. You're using
about the same amount of force your heart uses to
pump blood out to the body. Even at rest, the muscles of
the heart work hard--twice as hard as the leg muscles of
a person sprinting.
What carries the blood?
• BLOOD VESSELS
are the hollow tubes
that carry your
blood around your
body.
• There are 3 TYPES:
– ARTERIES
– CAPILLARIES
– VEINS
What carries the blood?
• Arteries carry blood
away from the heart.
• They are very thick,
and have strong,
muscular walls to
withstand the
pressure created by
the heart.
What carries the blood?
• Capillaries are tiny
vessels that run
through your body
tissue.
• They are very thin
to allow oxygen and
waste to pass
between the vessels
and your cells.
What carries the blood?
• Veins carry blood
back to the heart.
• They have thinner
walls than the
arteries because
there is not as much
pressure from the
heart.
• This vast system of blood vessels arteries, veins, and capillaries - is over
60,000 miles long. That's long enough
to go around the world more than
twice!
What is your blood?
• Blood is not one single
substance – it is a mix of
liquid and cells.
• The liquid part of blood
is called plasma. It is
mostly water.
• The rest of the blood is
made of three types of
cells.
Is Blood Blue?
• Your veins are not actually blue. They are a
dark reddish-brown, but appear blue because
the fat under our skin only allows blue light
to travel all the way down to our veins. Since
it is the only color of light that makes it to
our veins, it is the only color that is reflected,
and thus our veins appear blue! I hope this
helps
• Everyone's skin is slightly different in color,
so the veins can look different in different
people, but blood is exactly the same color in
everyone. It still doesn't look red. That's
because we're seeing the *walls* of the veins
too.
What is your blood?
Red Blood
Cells carry
oxygen.
White
blood
cells fight
disease.
Platelets form
blood clots to
stop you from
bleeding too
much.