CARDIOVASCULAR
SYSTEM
The Heart - Structure
Aorta
Vena cavae
Semilunar valves
Pulmonary artery
Pulmonary veins
Left atrium
Right atrium
Bicuspid valve
Tricuspid valve
Right ventricle
Septum
(dividing wall)
Left ventricle
Cardiac muscle
CARDIOVASCULAR SYSTEM
Blood carries oxygen around the body to where it
is needed
http://www.youtube.com/watch?v=D3ZDJgFDdk0
Can you name any of the blood vessels that the
blood is transported in
•ARTERIES
•ARTERIOLES – very small arteries
•CAPILLARIES
•VENULES – very small veins
•VEINS
Blood Vessels – complete worksheet 2B
Non-elastic fibres
Non-elastic fibres
Arteries
Lumen
Muscle + elastic fibres
Arteries carry blood
away from the heart
and have a thick,
elastic, muscular wall.
They stretch as blood is
pumped in and the
muscle wall contracts to
force blood along.
Muscle + elastic fibres
Non-elastic fibres
Veins
Lumen
Veins have a relatively
thinner and less
muscular wall than
arteries. The blood is
under a lower pressure
than in the arteries.
Muscle + elastic fibres
Capillaries
Capillary walls are one
cell thick. Exchange of
nutrients and
respiratory gases occurs
across
their surface.
CARDIOVASCULAR SYSTEM
ARTERIES
The wall of the heart is supplied with blood from two
small vessels called the coronary ARTERIES. These can
be blocked by blood clots and when this happens
blood supplied to part of the heart wall is cut off,
resulting in sudden death.
The structure of ARTERIES, VEINS and CAPILLARIES is
different.
The ARTERIES have a relatively thick wall. Most ARTERIES and
ARTERIOLES (very small arteries) carry oxygenated blood
away from the heart.
They pulsate as the heart beats.
They are more elastic than VEINS and also have higher
pressure.
The PULMONARY ARTERIES are different, they carry deoxygenated blood from the heart to the lungs.
VEINS
VEINS carry de-oxygenated blood to the heart.
They have much thinner walls than arteries.
They contain many VALVES which keep de-oxygenated blood
flowing to the heart and avoid the possibility of blood flowing
backwards.
VEINS rarely pulsate.
They are less elastic than arteries.
They carry blood at a lower pressure.
The PULMONARY VEINS, which leave the lungs on the way to
the heart, are different from other veins, they carry
oxygenated blood.
Any vessel ENTERING the heart is called a VEIN.
CAPILLARIES
CAPILLARIES are vessels that link the ARTERIES with the
VEINS.
At one end they carry oxygenated blood which transfers
supplies of oxygen and nutrients to the muscles.
At the other end CAPILLARIES pick up waste and so carry deoxygenated blood into the VEINS.
How Blood is Pumped around the Body
 Blood flows around the body in a
‘figure of eight’ circuit, passing
through the heart twice on each
circuit.
 Blood travels away from the
heart through arteries (A).
Lungs
(A)
(A)
(V)
(V)
 Blood returns to the heart
through veins (V).
There are 2 separate ‘loops’ to the circuit:
 The top loop – carries blood from
the heart to the lungs and back.
 The bottom loop – carries blood from the
heart to all over the body and back.
Heart
Body
Worksheet 2D
• PULMONARY CIRCULATION
– CARRIES BLOOD FROM THE HEART TO
THE LUNGS AND BACK AGAIN
• SYSTEMIC CIRCULATION
– CARRIES BLOOD FROM THE HEART TO
THE REST OF THE BODY AND BACK
AGAIN
http://www.youtube.com/watch?v=nx-XRC_1n-Q&feature=related
Blood Flow around the Body – Top Loop
PULMONARY CIRCULATION
1. Blood leaves the right side of the heart via the pulmonary artery and goes to the
lungs where it is oxygenated.
Lungs
Pulmonary
artery
Pulmonary
vein
Heart
Body
2. It then travels back to
the left side of the heart
via the pulmonary
vein.
Blood Flow around the Body - Bottom Loop
Lungs
3. The left side of the heart
then pumps the oxygenated
blood around the rest of the
body for use, via the
aorta.
Vena Cava
4. Once the oxygen
has been used, the blood
becomes deoxygenated
and returns to the
right side of the heart
via the vena cava.
Aorta
Heart
Body
http://www.youtube.com/watch?v=kZzn_8ztPMA
Respiratory System – worksheet 2E
alveoli
epiglottis
larynx
trachea
bronchus
bronchioles
diaphragm
mouth
mouth
epiglottis
larynx
trachea
bronchioles
bronchus
alveoli
diaphragm
Functions of the elements of the
Respiratory system
Worksheet 2E
The Pharynx:
• The pharynx allows food and air to enter the
body.
Functions of the elements of the
Respiratory system
The Epiglottis
• The epiglottis prevents food from being
inhaled into the lower air passage (the
trachea).
Functions of the elements of the
Respiratory system
Larynx:
• This is commonly referred to as the voice box. Air passes
through the larynx into the trachea. Also within the larynx
are the vocal cords responsible for voice production.
Functions of the elements of the
Respiratory system
Trachea:
• This is commonly referred to as the windpipe. It comprises of
a large strong and flexible tube. It is vital that this tube
remains open, rings of cartilage ensure that this is so.
Trachea
Functions of the elements of the
Respiratory system
Bronchi:
• The trachea branches into two at its far end. These two
branches comprise the bronchi. There are two branches so
the air can pass into both the left and the right lung.
Functions of the elements of the
Respiratory system
Bronchioles:
• The bronchi divide into smaller and smaller tubes known as
the bronchioles.
Functions of the elements of the
Respiratory system
Alveoli:
• The alveoli are tiny air sacs found at the extreme ends of the
bronchioles. There are many millions of these and they go to
make up the vast majority of the lung tissue. It is here that
gaseous exchange take place.
Functions of the elements of the
Respiratory system
Lungs:
•
There are two lungs housed within the chest cavity. They can be inflated
and deflated similar to two balloons. They have the appearance and feel
of sponge because of the millions of tiny air sacs. The outer surface of the
lungs is covered by the pleura. The pleura is smooth and moist which
reduces the amount of friction exerted on the lungs as they expand and
contract.
Functions of the elements of the
Respiratory system
The Diaphragm:
•
•
The diaphragm is a muscle situated below the lungs, it seals the chest
cavity from the abdominal cavity. It is responsible for the action of
breathing.
By contracting and relaxing the diaphragm changes the pressure within
the chest cavity. When it is contracted air is drawn into the lungs and
when it is relaxed air is forced out of the lungs.
Diaphragm
Interactive Activities
http://www.vtaide.com/png/respiratoryF.htm
http://www.getbodysmart.com/ap/respiratorysy
stem/menu/menu.html
The mechanisms of breathing
worksheet 2F
•
Taking a breath is a result of a message from the
brain being sent to the lungs. This message is sent
because of the growing level of carbon dioxide in
the blood stream.
•
It is possible to voluntarily hold the breath for quite
a long time. However even people who are good
at doing this must eventually take another breath.
INSPIRATION
EXPIRATION
The recovery process
Recovery from vigorous exercise:
Worksheet 2G
Measures of the Respiratory system
Vital capacity:
• Vital capacity refers to the largest volume of air that
can be expired after the deepest possible inspiration.
Tidal volume:
• Tidal volume is the amount of air that is breathed in
and out whether at rest or during exercise.
The effects of exercise and training on the
respiratory system
• The production of carbon dioxide, water and
the release of energy
The effects of exercise and training on the
respiratory system
• Adults take between 12-18 breaths per minute when
resting, however during exercise we breath more
frequently in order to meet the need for increased
oxygen.
• Humans can increase their breathing rate up to 50
breaths per minute during intense activity.
How do we measure breathing?
Apart from running for the bus there are 5 tests of respiratory
performance


Vital Capacity. The maximum
amount of air that can be
breathed out (about 4.5 litres).
Respiratory Rate. How many breaths
we take depending on activity.

Residual Volume. The amount left
in the lungs (about 1.5 litres).

Tidal Volume. The amount of air
taken in or out depending on the
size of the lung.
Minute Volume. How much air is
breathed in a minute (tidal volume
x respiratory rate)*

Are you fit? (healthy fit that is)
• Why is it that fit athletes hardly get out of breath
while less fit people huff and puff?

Athletes get fitter
through training.

Their bodies are able to
use oxygen more
efficiently.


They use the maximum
amount of oxygen that
can be used during
exercise. This is known
as V02 max.

non athletes
are at 65%.*
Very fit athletes such as
middle and long distance
runners work at about 85%
of their maximum.
The benefits of exercise and training on the
respiratory system
• Exercise and training develops and affects the
circulatory and respiratory systems;
–
–
–
–
–
–
–
–
stronger heart muscle,
increased stroke volume,
increased cardiac output,
lower resting heart rate,
more efficient gaseous exchange,
increased vital capacity,
increased tidal volume,
increased oxygen debt tolerance
The effects and needs of different activities on
the respiratory system
• Different physical activities will put different
demands on the respiratory system.
• Some activities put a LARGE DEMAND on the system
(meaning heavy breathing) and some activities put a
SMALL DEMAND on the system (meaning easy
breathing).
ACTIVITY:
• Can you label the following activities, as either
making a LARGE DEMAND or a SMALL DEMAND on
the respiratory system?