Transcript Cardiovascular system

Year 10 GCSE
Body Systems.
Today
The Cardiovascular System or
Circulatory System
Today
We will aim to learn to:
1.
2.
3.
4.
Identify what the cardiovascular system is,
What makes up the CV system
The different elements and functions of
the CV system,
And how they work during exercise.
The Circulatory System
What is the Cardiovascular or circulatory system?
It is the blood, which is pumped round the body by the
heart, which flows along tubes called blood vessels.
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So what makes up the Circulatory system?
The Heart
The Blood
The Blood Vessels
Functions of the CV system
The circulatory system
has several functions
these are:
3.
4.
It is the body’s transport
system.
5.
1.
2.
Takes O2 and food to
every cell in the body.
Removes CO2 and other
waste products from
every cell.
Carries Hormones to
different parts of the
body.
Maintains Temperature
and fluid levels in the
body.
Prevents infections from
invading organism and
germs.
The circulatory system
Opposite is a simple
plan of the
Cardiovascular
system. It shows the
heart and 4 main blood
vessels.
Can you identify what
is what?
The circulatory system
What do you notice
about the circulatory
system?
The heart is divided
into 2 parts. Each part
is a pump, so the heart
is a double pump in a
double circulatory
system.
The circulatory system
The right side of the heart
pumps the blood (deoxygenated blood) to the
lungs to pick up oxygen.
The left side of the heart
pumps the oxygenated
blood around the rest of
the body.
The circulatory system
The heart has large
tubes to carry blood
from the heart to lungs
and body and vice
versa.
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These are called:
Blood vessels
How Blood is carried around
your body
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Your heart pumps
blood at HIGH
pressure into your
body.
The blood carries
OXYGEN to your
cells and eventually
back to your HEART
through various
different sized blood
vessels.
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These blood vessels
also vary in function
and are divided into 3
types.
These 3 types are:
 Arteries
 Capillaries
 Veins
How is blood carried around
your body
Every time your heart
beats, it pumps blood
at high pressure into:
1. Arteries – These
push blood into …..
2. Arterioles -Which
are smaller than
arteries. These
branch into……
Blood around the body
3.
4.
5.
Capillaries – Which are
tiny tubes that allow the
transfer of food and
oxygen to our cells.
Venules – Which are
larger than capillaries
and carry de-oxygenated
blood from our cells.
Veins – These are larger
than venules and carry
all de-oxygenated blood
back to the heart.
Structure of blood vessels
There are three types:
1.
Arteries
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Carry Oxygenated blood
away from our heart under
high pressure.
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The walls are the thickest of
all 3 blood vessels.
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Inner walls are smooth and
elastic, made of involuntary
muscle.
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The bloods high pressure
stretches the inner walls as it
is forced through.
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Walls contract forcing
blood towards the
Capillaries.
Largest Artery is the
AORTA, coming straight
from the heart.
Structure of blood vessels
2.
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3.
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Arterioles:
Arteries branch into
smaller tubes called
arterioles.
These connect arteries to
capillaries.
Capillaries:
Arterioles branch into
these.
Walls are so thin (1 cell
thick) so food and O2 can
pass into body cells and
tissues.
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So CO2 and waste products
can pass into Blood Stream.
Structure of blood vessels
4.
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Venules:
Blood then flows into these
vessels after it has given up
it’s oxygen (it is now dull red
/ de-oxygenated).
Venules connect capillaries to
veins.
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Larger than arteries, so BP is
lower.
Look similar to arteries, but
larger inner tube to get blood
back to heart as fast as possible.
BP is lower so blood is flowing
slower.
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Veins:
Carry De-oxygenated blood
back to the heart, muscle
contractions / valves prevent
backflow of blood
Largest Vein is the VENA
CAVA.
Valves and Veins
Why do Veins have Valves?
1.
To keep blood flowing in
one direction.
2.
To stop blood flowing
backwards.
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Many Veins are near
muscles of your arms
and legs.
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As muscles contract it
pushes the blood towards
the heart through next
valve.
Arteries and Veins
If the Aorta and Vena cava carry blood to and from
the heart from the body, what do we call the tubes
that carry the blood to and from the lungs?
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The Pulmonary artery – carries blood from the
heart to the lungs to pick up oxygen, it’s the only
artery that carries de-oxygenated blood.
The Pulmonary vein – carries oxygenated blood
from the lungs to the heart.
Arteries and Veins
The circulatory system and
exercise
During exercise there
are certain changes
that the circulatory
system goes through
to adapt to exercise.
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Can you guess what
changes the
circulatory system
goes through?
The circulatory system and
exercise
The changes that occur
are:
1.
2.
3.
During exercise cell
respiration increases, so
CO2 levels in the blood
increase.
More CO2 passes out of
the blood and more O2
passes into it.
Blood flow increases, so
more O2 reaches the
working muscles.
The circulatory system and
exercise
4.
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Blood gets shunted from
where it is less needed to
where the action is. E.g. from
the stomach to the legs.
This happens by blood vessels
widening (Vasodilation) and
constricting
(Vasoconstriction) at different
points.
Exercise generates heat. So
the blood gets hotter. More
blood is shunted close to the
skin to cool down. This
makes the skin redden.
Today
We have learnt:
What the Cardiovascular system is made up
off.
 The functions of the CV system.
 The name of the major blood vessels.
 How blood is transported around the body.
 How the CV system responds with exercise.
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