Download Circulatory System - Mahtomedi Middle School

The Circulatory
System
Chapter 16
Blood moves like this. . . .
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Right side of the heart
Lungs (here it gets oxygen)
Left side of the heart
Body (here it drops off the oxygen)
Cardiovascular System
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Also called the Circulatory System
Made up of:
Heart
Blood
Blood vessels
How Do Blood and Air Travel?
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
Blood is liquid
tissue.
The heart is the
main organ that
makes up the
circulatory
system.

You’re not writing
anything from
this slide.
It is the job of the Circulatory
System to move blood through
blood vessels to the body’s cells.

You’re not writing
anything from
this slide.
Blood Carries these things to your
body’s cells…

Food

Oxygen

Water
Interesting Facts…..(no you don’t
have to write this)…
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Sponges and cnidarians don’t have a
circulatory system.
Insects and other invertebrates have open
circulatory systems.
Each time the heart beats…

It pushes blood through the
blood vessels of the
cardiovascular system
Upper Chambers
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Left and right atrium
There are two
Their job is to receive blood that
comes from the body
Lower Chambers
•Left and right ventricle
•There are two
•Their job is to pump blood out of
the heart
More Parts of the Heart
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
VALVES – flaps of tissue that prevent
blood from flowing backward
PACEMAKER – group of cells that adjusts
the speed of the heart beat
Found
in the right atrium

When blood flows through the heart,
the force that pushes blood out of the
heart and into the arteries is . . .
the contraction of the ventricles
Two Loops

The three kinds of blood vessels are:
Veins
Arteries
Capillaries
What about the capillaries?
•This is what
connects the
arteries and the
veins. It is
where diffusion
happens.
•Remember
diffusion??? The
movement of
molecules from
more to less
We’ll talk about this more later.
crowed areas.
Pathway of non-oxygenated
blood
Blood without oxygen enters the :
Vena Cava → Right atrium → Tricuspid
Valve → Right ventricle → Pulmonary
Valve → Artery → Lungs
 In
lungs, blood picks up O2 and releases
CO2.
 Then
O2 rich blood returns to the heart
Arteries

Arteries
carry
blood
away
from the
heart
Arteries
Made of Three Layers

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inner layer --epithelial cells
middle layer -- muscle tissue
outer wall -- flexible connective
tissue.
Major Arteries


Aorta – largest
artery in the body.
Carries blood from
the heart to the
rest of the body.
Coronary
Arteries – bring
blood to the
heart
More Artery Info
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Pulse is caused by the expanding
and narrowing of artery walls.
When you count pulse beats, you are
also counting heartbeats.
Arteries control the amount of
blood that different organs receive.
Capillaries

In capillaries,
CO2 and O2 are
exchanged
between the
blood and the
body’s cells

This happens by
diffusion
Main Job of the Veins…
Veins
carry blood back to the ♥
 Since
most are carrying waste they are
purplish/bluish in color
 The
walls are very thin which is why you
can see the color through your skin.
Main Job of the Veins…
 Veins
carry blood back to the ♥
 Walls
of veins are generally thinner than
arteries.
 Because
of this… you can see the color
through your skin
•Since most are carrying waste they are
purplish/bluish in color.
What keeps blood moving? – 3 things…
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contraction of nearby skeletal muscles
valves that prevent blood from flowing
backward
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The vein valves are necessary to keep blood flowing
toward the heart, but they’re also necessary to allow
blood to flow against the force of gravity. For example,
blood that is returning to the heart from the foot has to
be able to flow up the leg. Generally, the force of gravity
would discourage that from happening. The vein valves,
however, provide footholds for the blood as it climbs its
way up.
breathing movements that squeeze veins
in the chest
Blood Pressure
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Blood pressure is the pressure that blood
exerts against the walls of the blood
vessels.
As blood moves away from the heart, the blood
pressure decreases.
The instrument that measures blood pressure is
a sphygmomanometer.
Superior
vena cava
Inferior
vena cava
septum
Pulmonary veins & valves
aren’t shown here