The
Circulatory
System
Name: _________________________ Class: __________________
1. What are the MAJOR PARTS of the circulatory system?
2. What are the MAJOR FUNCTIONS of the circulatory system?
The Heart
The heart is the pump that pushes the blood around tho body. It is about
the size of a clenched fist and sits in the centre of your chest behind your
rib cage and sternum (the bone that runs down the middle joining the
two sides of your rib cage).
The heart you see drawn
on the average Valentine
is only a rough
representation of the
actual structure of the
heart. Your heart is
actually shaped more like
an upside-down pear.
EXTERIOR VIEW of the heart
The outside of the heart is surrounded by a membranous sac.
 What is this sac called and what is its function?
 Label the parts of the heart that you can see just by looking at the outside of it.
XOR

INTERIOR VIEW of the heart
 Label the parts of the heart that you can see. Label the direction of blood flow through the heart.
VESSELS in the heart
The heart is surrounded by a number of vessels that carry blood either:
 TO the heart, or
 AWAY from the heart
Your heart is about
the size of your
clenched fist.
The blood that is carried by the vessel can be either:
 OXYGENATED (with oxygen)
 DEOXYGENATED (without oxygen)
 Complete the table below by saying if the vessel carries OXYGENATED or DEOXYGENATED blood and
saying where it carries blood TO and FROM.
Vessel
Carries …
From …
To …
Vena Cava
(superior and inferior)
Pulmonary artery
Pulmonary vein
Aorta
Blood Vessels
The blood is carried in a series of continuous tubes of different sizes celled blood vessels. They carry the
blood to each organ in the body and take it back to the heart. In each organ blood vessels allow chemicals
to move into and out of cells.
The direction of blood flow is kept up by the pumping of the heart. When the powerful muscles of your
heart contract, they force blood out into tubes called arteries. The arteries branch into tiny little tubes
called capillaries. The capillaries join together to form veins. The veins carry blood back to the heart.
 Your task it to create a PowerPoint about the three types of blood vessels: arteries, capillaries and veins.
Information to include:
 Structure - wall thickness; layers; size of lumen. Include short explanations as to why the blood
vessel has this structure, eg. Why are artery walls elastic? Why are capillary walls very thin?
 Function – what is the purpose of each of the blood vessels (eg where do they carry blood?)
 Blood - type of blood carried


Special features – presence of valves, pulse etc
Major arteries and veins – list some of the major arteries and veins inside the human body
(diagram would also be lovely)
You can use your textbook (p. 155) and/or the websites below (or ones you fin d yourself – remember to
keep a record of these sites)
http://www.fi.edu/learn/heart/vessels/vessels.html
http://www.ivy-rose.co.uk/Topics/Blood_Vessels.htm
http://library.thinkquest.org/22016/circ/index.html
http://www.health-massagers.co.uk/gbu0-display/art.html
Diagrams, pictures and illustrations are highly recommended! But only if they help enhance your written
information and help you to understand what it is you are writing/reading.
** You will need to be able to identify diagrams of the different blood vessels.
Bonus Questions
Answer these questions on a slide at the end of your PowerPoint.
1. What are arterioles and venules?
2. When you go to the doctor you sometimes have your blood pressure checked. What is the instrument
called used to read blood pressure? Which artery is used to measure your blood pressure? Why are
arteries involved in measuring blood pressure and not veins?
3. Find out about blood vessel transplants.
VALVES inside the heart
The direction of blood flow in the heart is controlled flaps of tissue called valves. This means the valves
stop blood from moving in the wrong direction. There are four valves inside the heart, but you only need to
know two of them:

____________________ valve

____________________ valve
 Label the valves on the diagram below. Make sure you mark the valves you need to know!
How does the HEART BEAT?
The inside of the heart contains special tissue that regulates heart beat. This tissue is called conductive
tissue. There are two positions on the heart where there are dense regions of this conductive tissue.

______________________________ node

______________________________ node
 Label these on the diagram below.
The ____________________ node is a cluster of specialised cardiac cells in the wall of the right
_______________. This ‘pacemaker’ initiates the heart beat; this means it starts the heart beating.
The ____________________ node is another cluster of specialised cardiac cells. It is found at the base of
the right atrium, just above the right _______________. It is the secondary pacemaker and regulates the
beating o the _______________.
BLOOD FLOW TROUGH THE HEART
All of the parts of your heart, like the chambers and the valves, work together to
ensure that blood always flows on the same path on its way through your heart.
 Visit the website below. Scroll down until you find FIGURE 1. Click on CLICK TO ENLARGE AND INTERACT.
Watch the animation step-by-step by clicking on STEP THROUGH. As you watch the animation, fill in the
blanks below, using the term at the bottom of the page.
http://www.bostonscientific.com/templatedata/imports/HTML/lifebeatonline/winter2007/learning.shtml
The path blood takes through the heart.
Deoxygenated blood from your body returns to the heart via the _______________ vena cava (head and
upper body) and the _______________ vena cava (legs and lower body), entering the right
_______________.
From the right atrium, the blood flows through the _______________ valve and into the right
_______________.
The right ventricle then pumps blood into the _______________ artery. This carries the deoxygenated
blood to the _______________.
At the lungs, the blood’s _______________ supply is replenished. The blood is now referred to as
_______________.
Oxygenated blood flows back to the heart via the _______________ veins, entering the left
_______________.
From the left atrium, the blood flows through the _______________ valve and into the left
_______________.
The left ventricle then pumps blood into the _______________. This carries the oxygenated blood to the
rest of the _______________.
inferior
lungs
oxygen
aorta
ventricle
pulmonary
body
Superior
atrium
bicuspid
pulmonary
ventricle
tricuspid
atrium
oxygenated
Follow-up Questions
 Answer the following questions about the flow of blood through the heart, using the website below to
help you – you will need to watch the animation and read the text information.
http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_pumping.html
1. What is the function of the four valves inside the heart? What are their names?
2. Fill in the blanks.
The right side of the heart pumps blood from the _______________ to the ______________, through the
______________ artery.
The left side of the heart pumps blood from the ______________ to the ______________, through the
______________.
3. Blood that is low in oxygen is called:
___________________
Blood that is high in oxygen is called:
___________________
4. What causes the right atrium to contract? What happens when the right atrium does contract? What is
this process called?
5. What causes the tricuspid valve to close? Why does this valve need to close?
6. What happens during ventricular systole?
7. As deoxygenated blood enters the right atrium causing the right atrium to contract, what is happening in
the left side of the heart?
8. What causes the bicuspid (mitral) valve to close? Why does this valve need to close?
9. What happens during ventricular systole (ventricle contracts) in the left side of the heart?
10. After the blood leaves the ventricles (both right and left) what is happening in the two atria?
11. Your heart beat sounds something like “lub – dub”. What is the sound of the “lub”? What is the sound
of the “dub”?
12. Each heartbeat has two basic stages: diastole and systole. What happens during diastole? What
happens during systole?
13. What is the function of the pericardium?
14. How do you know which blood vessel is the aorta?
15. What is the function of the blood vessels that run over the surface of the heart?
16. What are the names of the four chambers of the heart?
17. There is a notable difference in the thickness between the walls of the atria and the ventricles. Which
are thicker? Why is there this difference?
18. There is also a difference in the thickness between the walls of the two ventricles. Why is this so?
19. Why do some blood vessels (the arteries) have thick walls and some (the veins) have thin walls?
Heart Conditions
Observe the changes which occur when the heart stops working efficiently and effectively.
http://www.bostonscientific.com/lifebeat-online/resources/compare-heartconditions.html?
Heart Transplant
The first human heart transplant was performed in South Africa in 1967, and Australia’s first heart
transplant took place in Sydney in 1968. On average 70 people receive a heart transplant per year in
Australia. Heart transplant is major surgery and is the last resort for people suffering from chronic heart
diseases and illnesses. Generally the heart transplant should significantly improve the patient’s life
expectancy and quality of life. Approximate survival values for heart transplantation are 80%, 70% and 55%
at 1, 5 and 10 years respectively.
To be able to perform heart transplants you need to be a fully qualified cardiologist and surgeon,
this means YEARS or University and on-the-job training.
However, you can step into the shows of a heart transplant surgeon by visiting the website below
and perform a simulated heart transplant.
http://www.pbs.org/wgbh/nova/eheart/transplantwave.html
Blood
Who needs blood? We do. Without blood, our bodies would stop
working. Blood is our body’s liquid messenger. Even though you cannot
see it, blood is everywhere in your body. It tastes salty, like tears.
Blood’s job is to carry oxygen and nutrients to all parts of your body,
and carry carbon dioxide and other waste products back to the lungs,
kidneys and liver to get rid of. It fights against infection and helps heal wounds, so we can stay healthy.
There is no substitute for blood.
 Read the section titled BLOOD on pages 149-150 of your Science Aspects 2 textbook.
Complete the table about the components of blood on the back of this page.
The website below will be useful:
http://www.fi.edu/learn/heart/blood/blood.html
 When you have finished your table, read the article called KEEPING US WORKING, and answer the
questions below. The article may also be useful in adding to your table.
1. Where are blood cells made? Give two examples of places in your body where they are made? What is
the name of the ‘parent’ cell that all blood cells develop from?
2. Why does blood sometimes appear to be red and at other times it is blue? What is haemoglobin and
what role does it play in the ‘colour’ of blood?
3. The brain receives 15%-20% of the body’s blood supply. Why is this so important?
Development of Blood Cells
Red Blood Cells
Scientific Name
Diagrams and Description
(structure/appearance?)
Function
(what is their job?)
Numbers
(how many?)
Life cycle
(where are they made? how
long do they live for?)
White Blood Cells
Platelets
Plasma
BLOOD TYPES
The Australian Federal Government has declared 2009 as the Year of the Blood Donor.
Blood donations are extremely important as this blood can be used to save lives
following a traumatic accident where lots of blood is lost, during surgery and to help
with the treatment of cancers and other illnesses.
Everybody’s blood is not the same. There are different types or groups of blood. These types/groups
determine who can use your blood if you chose to donate and whose blood you can use if you are in need
of a blood transfusion.
 Read the section titled BLOOD GROUPS. Then visit the Red Cross Website below and answer the
following questions:
http://www.donateblood.com.au/page.aspx?IDDataTreeMenu=42&parent=30
1. There are four main blood types – A, B, O and AB. Fill in the table below.
A
B
O
% of Australians
with this blood
type
How in demand is
this blood type?
Who can use this
blood type?
In an emergency,
what blood type
could be given to
this person?
2. Looking at the graph at the top of the webpage, answer the following:
a. Most common blood type:
__________
b. Least common blood type:
__________
3. Find out what the + and – (Rhesus Factor) means. How was it discovered?
AB