Download Circulatory system

S. MORRIS 2006
What does the Circulatory
System do?
Function:
The job of the circulatory
system is to carry blood to
and from different places
in the body.
What are the main structures of
the Circulatory System?
Structures:
1. The Heart
2. Blood
3. Blood Vessels
The Heart
• The Heart is a (cardiac)
muscle that has the job of
pumping blood around the
body.
• The average human heart
beats 72 times a minute.
• The average human heart
will beat 2,500,000,000
times during their lifetime.
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
2 ventricles
Coronary arteries,
the hearts own
blood supply
The heart has four chambers
now lets look inside the heart
what’s in
digested food
red blood cells
white blood cells
oxygen
waste (urea)
platelets
carbon dioxide
plasma
hormones
The Blood
red blood cell
platelets
white blood cell
plasma
Composition of Blood
• The Plasma (Fluid)
– makes up 55% of
the blood volume.
• The Solids (Cells)
Composition of Blood
45%
55%
– make up 45% of
the blood volume.
Plasma
Solids
Plasma
•Plasma is
90% water
A yellow colored
liquid that
carries the cells
and the
platelets.
Blood Solids
Composition of Blood
• Red Blood Cells 43%
• White Blood Cells 2%
• Platelets
2%
43%
55%
Plasma Red blood cells White blood cells
Red Blood Cells
a disc that is
round and flat
without a nucleus
hold oxygen and
carry it to cells
that need it.
can change shape to an amazing extent,
without breaking, as it squeezes single
file through the capillaries.
White Blood Cells
‘Eat’ and digest
micro-organisms
•Fight disease by
making antibodies to
destroy invaders
•Make antitoxins to
break down poisons
Platelets
Platelets are bits of cells
broken off larger cells.
Platelets produce
enzymes to form a
net. This net traps
other blood cells to
form a blood clot.
Blood clots stop
bleeding.
Where is blood made?
Blood cells are
made in the
marrow of
your bones.
Blood Vessels
• Blood from the heart gets around the
body through blood vessels
• There are 3 types of blood vessels
1. ARTERY
2. VEIN
3. CAPILLARY
The Artery
• Arteries carry blood away from
the heart. Arteries Away
• They are red because they
contain oxygenated red blood
cells
• Arteries carry oxygen and
nutrients (digested food) to your
body’s cells.
• Arteries are under pressure
created from the heart beat.
The Vein
• Veins carry blood back
towards to the heart
• Veins contain blood filled with
waste like carbon dioxide.
• Veins have valves which act to
stop the blood from going in
the wrong direction.
More Veins…
Why do they appear blue?
–They are actually
dark red.
–They appear blue
because of light
refraction through
the skin.
The Capillary
• Capillaries link arteries to veins
• They exchange materials from your blood to
the cells in your body
– Oxygen is dropped off
– Carbon dioxide is
picked up
More Capillaries…
• The wall of a capillary is only one cell thick!
They are so tiny that blood cells have to pass
through them single file.
• Release excess heat through capillaries- that’s
why your face gets red when you exercise.
Summary
• The three main parts of the circulatory system
are the heart, the blood and the blood vessels
• The job of the circulatory system is to move
blood throughout your body
• Your blood transports oxygen, waste, and
nutrients throughout the body
Exit Ticket: Write a love poem
• Pretend you are the
circulatory system and you
are in love with respiratory
system
• Write a short love poem to
convince the respiratory
system why you two are such
a good match and why you
cannot function without them