Mrs. Degl
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What is the circulatory system?

The circulatory system carries blood and dissolved
substances to and from different places in the body.

The Heart has the job of pumping these things around
the body.

The Heart pumps blood and substances around the
body in tubes called blood vessels.

The Heart and blood vessels together make up the
Circulatory System.
Mrs. Degl
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How does this system work?
pulmonary vein
pulmonary artery
lungs
head & arms
aorta
main vein
Right
Left
liver
digestive system
kidneys
legs
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Our circulatory system is a double circulatory system.
This means it has two parts parts.
Lungs
the right side of
the left side of
the system
the system
deals with
deals with
oxygenated
deoxygenated
blood.
blood.
Body cells
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The Heart
This is a vein. It brings
blood from the body,
except the lungs.
These are arteries.
They carry blood
away from the heart.
2 atria
Coronary arteries,
the hearts own
blood supply
2 ventricles
The heart has four chambers
now lets look inside the heart
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The Heart
Artery to Lungs
Artery to Head and Body
Vein from Head and Body
Vein from Lungs
Right Atrium
Left Atrium
valve
valve
Left Ventricle
Right Ventricle
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How does the Heart work?
STEP ONE
blood from the
body
blood from
the lungs
The heart beat begins when the
heart muscles relax and blood
flows into the atria.
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How does the Heart work?
STEP TWO
The atria then contract and
the valves open to allow blood
into the ventricles.
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How does the Heart work?
STEP THREE
The valves close to stop blood
flowing backwards.
The ventricles contract forcing
the blood to leave the heart.
At the same time, the atria are
relaxing and once again filling with
blood.
The cycle then repeats itself.
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blood from the heart gets around
the body through blood vessels
There are 3 types of blood vessels
a.
ARTERY
b.
VEIN
c.
CAPILLARY
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The ARTERY
Arteries carry blood away from the heart.
the elastic fibres allow
the artery to stretch
under pressure
thick muscle and
elastic fibres
the thick muscle can
contract to push the
blood along.
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The VEIN
Veins carry blood towards from the heart.
veins have valves
which act to stop the
blood from going in
the wrong direction.
thin muscle and
elastic fibres
body muscles surround the veins so
that when they contract to move
the body, they also squeeze the
veins and push the blood along the
vessel.
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The CAPILLARY
Capillaries link Arteries with Veins
they exchange materials
between the blood and
other body cells.
the wall of a capillary
is only one cell thick
The exchange of materials
between the blood and the
body can only occur through
capillaries.
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The CAPILLARY
A collection of capillaries is known as a capillary bed.
artery
vein
capillaries
body cell
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what’s in
digested food
red blood cells
white blood cells
oxygen
waste (urea)
platelets
carbon dioxide
plasma
hormones
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The Blood
white blood cell
red blood cell
platelets
plasma
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Red Blood Cells
contain haemoglobin, a
molecule specially designed
to hold oxygen and carry it
to cells that need it.
a biconcave disc that is
round and flat without a
nucleus
can change shape to an
amazing extent, without
breaking, as it squeezes
single file through the
capillaries.
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White Blood Cells
there are many different types and
all contain a big nucleus.
Phagocytes ‘eat’ and digest microorganisms .
the two main ones are the Lymphocytes and the
Phagocytes.
Some lymphocytes fight disease by making antibodies to destroy
invaders by dissolving them. Other lymphocytes make antitoxins to
break down poisons.
Active immunity can happen when the body detects a foreign substance
and develops antibodies to kill it. After the virus is over the body
keeps it’s antibodies to protect against future infections. Vaccines
produce active immunities. Passive immunities can happen when a
person receives antibodies from the blood of another person or animal
(blood transfusions or eating meats). These are temporary.
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Platelets
Platelets are bits of cell
broken off larger cells.
Platelets produce
tiny fibrinogen
fibres to form a net.
This net traps other
blood cells to form a
blood clot.
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Plasma
It also contains useful
things like;
• carbon dioxide
• glucose
A strawcoloured
liquid that
carries the
cells and the
platelets
which help
blood clot.
• amino acids
• proteins
• minerals
• vitamins
• hormones
• waste materials
like urea.
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According to the AB0 blood typing system there are four different
kinds of blood types: A, B, AB or 0 (null).
Blood group A
If you belong to the blood group A, you have A antigens on the
surface of your red blood cells and B antibodies in your blood plasma
Blood group B
If you belong to the blood group B, you have B antigens on the
surface of your red blood cells and A antibodies in your blood plasma.
Blood group AB
If you belong to the blood group AB, you have both A and B antigens
on the surface of your red blood cells and no A or B antibodies at all
in your blood plasma.
Blood group O
If you belong to the blood group O (null), you have neither A or B
antigens on the surface of your red blood cells but you have both A
and B antibodies in your blood plasma.
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Disorders of the Transport System
•Diseases of the heart and blood are cardiovascular
diseases.
•High blood pressure is called Hypertension, which can
damage the arteries and weaken the heart muscle.
•Anemia results when the blood cannot carry enough
oxygen to the body cells.
•Angina is a narrowing of the coronary artery which slows
blood flow to the heart. This causes shortness of breath
or chest pains. This leads to a hear attack.
•Leukemia is a form of cancer in which the bone marrow
produces abnormally large numbers of white blood cells.
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SUMMARY
copy and complete the following;
away from the heart. The walls of an artery
Arteries take blood ______
muscular walls and elastic fibres. Veins
are made up of thick _________
towards the heart and also have valves. The
carry blood ________
capillaries link arteries and veins, and have a one cell thick wall.
_________
plasma the liquid part of the
Blood is made up of four main things ______,
oxygen White Blood cells to protect
blood; Red Blood Cells to carry ______;
platelets to help blood clot.
the body from disease and _________
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