Transcript The Circulatory System

THE CIRCULATORY
SYSTEM
WHAT DO WE KNOW ABOUT THE
HEART?
ANYTHING YOU ARE CURIOUS
ABOUT?
Quick Vid of Heart Animation
 The heart and circulatory system (also called the
cardiovascular system) make up the network that
delivers blood to the body's tissues.
 With each heartbeat, blood is sent throughout our
bodies, carrying oxygen and nutrients to all of our
cells.
 Remember that a tissue is an ensemble of cells, not
necessarily identical, but from the same origin, that
together carry out a specific function. Organs are
then formed by the functional grouping together of
multiple tissues.
 Every day, the approximately 5 liters of blood in
your body travel many times through about 96,560
kilometers of blood vessels that branch and cross,
linking the cells of our organs and body parts.
 From the hard-working heart, to our thickest
arteries, to capillaries so thin that they can only be
seen through a microscope, the cardiovascular
system is our body's lifeline
 Read page 90-91 in the text book.
 Copy the diagram from page 89 into your notebook.
 Complete question 3 and 4 on page 89.
THE HEART
 The heart is the key organ in the
circulatory system. As a hollow,
muscular pump, its main function
is to propel blood throughout the
body. It usually beats from 60 to
100 times per minute, but can go
much faster when it needs to.
 It beats about 100,000 times a
day, more than 30 million times
per year, and about 2.5 billion
times in a 70-year lifetime.
THE CIRCULATORY SYSTEM
Your heart is a muscle that sends blood around
your body, providing oxygen and nutrients. It
also carries away waste.
Your heart is like two pumps.
The right hand side receives blood from the
body and pumps it to the lungs where it
deposits the carbon dioxide.
The left hand side receives oxygenated blood
from the lungs and pumps it out to the body.
Your heart is made up of 4 blood filled
chambers.
There are two chambers on each side of the
heart. One chamber is on the top and one on
the bottom.
The two chambers on the top are called the
atria. There is a left and a right one.
The atria fill with blood returning to the heart
from the body and lungs.
The two chambers at the bottom are called the
ventricles. There is a left and a right ventricle.
Their job is to pump out the blood to the body
and lungs.
Running down the middle of the heart is a
thick wall of muscle called the septum. It
separates the left and right side of the heart.
THE HEART
 Photo gallery
MINI-EXPERIMENT
Question: How many beats per minute do you
think your heart would beat if you were sitting,
walking or running?
Hypothesis:
Sitting: ___ beats per minute
Walking: ___ beats per minute
Running: ____ beats per minute
Conclusion:
How close were your predictions? What was
your actual beats per minute for each activity?
What did you notice?
 Your heart pumping
THE CIRCULATORY SYSTEM
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Please read the handout on the circulatory
system.
Please draw, colour and label a sketch of a
heart – needs to be at least half a page.
Answer the following questions:
What is your heart made out of?
What does the left hand side of your heart
do?
What does the right hand side of your heart
do?
What does the word “circulatory” mean?
The atria and the ventricles work as a team.
The atria fill with blood then dump it into the
ventricles. The ventricles squeeze, pumping
blood out of the heart. While the ventricles
are squeezing, the atria refill and get ready for
the next contraction.
Your blood knows where to go thanks to 4
special valves inside the heart. A valve lets
something in and keeps it there by closing.
Two of the heart valves are called the mitral
and the tricuspid. They let blood flow from the
atria to the ventricles.
The other two valves are called the aortic and
the pulmonary. They are in charge of
controlling the flow of the blood leaving the
heart.
The valves all work to keep the blood flowing
forward.
Your blood moves through many tubes in your
body once it leaves your heart.
Blood vessels are made up of many tubes
called veins and arteries that are attached to
the heart.
The blood vessels that carry blood away from
the heart are called arteries.
The blood vessels that carry blood to the heart
are called veins.
 A network of tiny capillaries connects the arteries
and veins.
 Even though they're tiny, the capillaries are one of
the most important parts of the circulatory system
because it is through them that nutrients and oxygen
are delivered to the cells.
 In addition, waste products such as carbon dioxide
are also removed by the capillaries.
DID YOU EVER WONDER ABOUT THE PROCESS
BEHIND YOUR BEATING HEART?
A healthy heart makes a "lub-dub" sound with
each beat. Here's what happens to make that
sound: One complete heartbeat makes up a
cardiac cycle, which consists of two phases. In
the first phase, the ventricles contract (this is
called systole) sending blood into the
pulmonary and systemic circulation. To prevent
the flow of blood backwards into the atria
during systole, the atrioventricular valves
close, creating the first ("lub") sound.
 When the ventricles finish contracting, the aortic and
pulmonic valves close to prevent blood from flowing
back into the ventricles. This is what creates the
second sound (the "dub").
 Then the ventricles relax (this is called diastole) and fill
with blood from the atria, which makes up the second
phase of the cardiac cycle.
The movement of blood through your heart
and body is called circulation. Your heart is
very efficient – it takes less than 60 seconds
to pump blood to every cell in your body.
All of your cells need oxygen and would die
without a steady supply of oxygenated blood .
Each time the blood circulates from the heart
out to the body, about 1/5 or 20% of it goes
through the kidneys. The kidneys filter out
some of the waste from the blood before it
heads back to the heart.
WHAT YOU NEED TO KNOW
Review For Quiz:
Be able to explain how your heart pumps
blood.
What the kidneys do.
Define the following terms:
 Atria
 Valve
 Vein
 Ventricle
 Artery
 Septum