Download Circulation

Ch 11
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Circulatory System
 Blood
 Blood Vessels
 Heart
Purpose:
 1) To deliver oxygen, water and food
to the body
 2) To remove waste such as Carbon
Dioxide
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Not all animals have circulatory systems
 Simple animals
 Sponge, sea anemone and hydra
 Their bodies are only a few cells thick
 Water flows freely
 Oxygen and nutrients diffuse from the
water to the body
 Carbon Dioxide flows into the water
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Some animals
have a closed
circulatory
system
 Worms
This means
blood flows
through tubes
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Some animals
have an open
circulatory system
This means their
blood flows
freely through the
body
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Divided into right
and left
Each side has a small
chamber on the top
(atria)
And a large chamber
on the bottom
(ventricles)
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Resting heart rate is 60 to 80 beats per
minute
Running heart rate is up to 150 times
per minute!
Will pump more then two billion time
in your lifetime
Structure of the heart allows blood to
only flow in one direction.
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Artery – carries blood AWAY from the
heart
Vein -- carries blood TOWARD the
heart
Needs Valves
 Flaps in the heart that keep blood
flowing in one direction
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Tricuspid valve -- valve between the
right atrium and right ventricle.
Bicuspid valve (mitral) – valve between
the left atrium and left ventricle.
Semilunar valve – are located between
the ventricles and their arteries
Valves closing are what causes your heart
beat
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1) Blood enters the right side of the
heart at the right atrium via the vena
cava (largest vein in the body)
 Little oxygen at this point
2) Pumped to right ventricle
3) Pumped to pulmonary artery – carries
blood to lungs
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4) Blood enters both lungs
 Blood picks up oxygen here
 Blood loses carbon dioxide here – now
bright red
5) Returns to the heart through
pulmonary veins
Left side
Takes less then 10 seconds for blood
to go from heart to lungs
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1) Blood rich in oxygen arrives at the
left atrium
2) Left atrium to left ventricle
3) Blood pumped from the ventricle to
the large aeorta
4) Blood goes to body parts
5) Goes back to the heart (right side) is
once again blue.
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Carry blood away from heart
Blood is squeezed into artiries
 Blood pressures
 The force created when blood pushes
against the walls of vessels
Important traits
 Carry blood away from the heart
 They carry blood under high pressure
 Round with thick muscular walls
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Bring blood to the heart
Less muscular than arteries, flatter and
wider
Many valves
Under low pressure
Carry blood to heart, carry blood under
low pressure, flat with little muscle,
many one-way valves.
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Smallest kind of blood vessel.
One cell thick.
Thinner than a page in a book.
More capillaries than any other blood
vessel.
Bring blood close to all body cells.
All gas exchanges occur in capillaries.
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High blood pressure – hypertension –
caused partially by cholesterol.
Heart attack – blood vessels that carry
blood to and from heart are called
coronary vessels.
Heart attack is the death of heart muscle.
Avoid problems:
 Eat well
 Exercise
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In 2005, 652,091 people died of heart disease
(50.5% of them women). This was 27.1% of all
U.S. deaths.
Heart disease is the leading cause of death for
American Indians and Alaska Natives, blacks,
Hispanics, and whites. For Asians and Pacific
Islanders, cancer is the leading cause of death
(accounting for 27.5% of all deaths), heart disease
is a close second (25.0%).
Worldwide, coronary heart disease killed more
than 7.6 million people in 2005.