The
Circulatory System
How it all gets around in
your body!
What is it??
 Advanced organisms,
including you, have closed
circulatory systems
where the heart is
connected to a complete
system of vessels.
 The fluids of a closed
circulatory system never
leave the vessels!
What does this system do?
 How does circulatory
system help you?
 The circulatory
system carries
nutrients and
chemicals to all points
in your body.
 The fluids also carry
waste products and
dissolved gases for
your cells.
Circulation is the key !
 The human circulatory system
consists of the heart, blood vessels,
and the blood that flows through
them.
 The blood vessels may be veins, which
carry oxygen-poor blood to your
heart or arteries, which carry
oxygenated blood away from your
heart to the rest of your body.
It is like a transportation
system!
Think of the chemical compounds as cars and the
circulatory system as a network of freeways,
main streets, and side streets.
What does this system do?
The cars can pass from one building to another using
these streets in the same way.
Basic Parts
 Humans have a
fourchambered
heart.
 The heart is
the pump for
the system.
 The heart consists of 2 pumps.
 The pump on the right side of the
heart sends blood to the lungs
where the blood obtains oxygen.
 The blood which now has oxygen
then travels back to the heart
where it is pumped to all parts of
the body.
Basic Parts
 As blood is
pumped from the
heart, it passes
through a system
of arteries, and
then capillaries.
 The capillaries are
the vessels that
allow for most of
the transfer of
compounds and
dissolved gases.
Basic Parts
 Capillaries are very small and have thin walls to
allow easier passage of compounds including
nutrients, glucose, carbon dioxide, and waste
products.
 Capillaries connect the arteries to the veins.
That’s a wrap!
 After the
capillaries, your
blood passes
through veins.
 The veins lead
the circulatory
fluids back to
the heart.
Interacting with other systems
 The circulatory system touches every
organ and system in your body.
 The system is connected to all of your
body's cells so that it can transport
oxygen efficiently.
 When you breathe, the circulatory
system carries oxygen to your cells
and carries dissolved carbon dioxide
back to the lungs.
Interacting with other
systems
 Your respiratory system
is all about exchanging
gases with the
environment (breathing).
 Taking in O2,
Releasing CO2
 You have two lungs and
the exchange of gases
between the circulatory
and respiratory systems
happens in the lungs.
Interacting with other
systems
 Every cell that needs oxygen, needs
access to the fluids in your circulatory
system.
 The circulatory system and its fluids
are super important to your digestive
system because it absorbs and
distributes the nutrients from your
food to the rest of your body.
See it in motion !
 http://www.echalk.co.uk/Science/Biology/
heart/heart.htm
 http://www.pbs.org/wnet/redgold/journey/
phase2_a1.html
FUN FACTS!
 The heart is the largest muscle in the
body.
 When you take your pulse or measure
your blood pressure, the blood being
used is flowing through the arteries
because the pressure is much higher
than the veins.
 Your lungs can hold as much air as a
basketball!
FUN FACTS
 Arteries carry bright red blood, and
veins carry dark red blood. Why?
 Blood circulates through the heart
more than 1000 times in one day!
 If you took out all of the blood
vessels in your body and laid them
in one line, the line would be over
100,000 miles long!!!!!
SEE THE CONNECTION?
 Your lungs trade air with your blood.
 The heart pumps used blood to the lungs
to get Oxygen.
 The lungs take the Carbon Dioxide out of
the blood.
 After the trading is done, the blood goes
back to the heart to be distributed
throughout the body.