Download THE CIRCULATORY AND RESPIRATORY SYSTEMS

2.3 The Circulatory and
Respiratory Systems
• The circulatory system consists of
the heart, arteries, capillaries, and
veins.
• Your heart is a pump that pushes
approximately 4 L of blood through
your body every minute.
• The main purpose of the
respiratory system is to exchange
gases.
• The main organ of the respiratory
system is the lungs.
See pages 82 - 83
(c) McGraw Hill Ryerson 2007
Amazing Heart Facts
Put your hand on your heart. Where is it?
•Hold out your hand and make a fist.
size of heart: child = 1 fist; adult = 2 fists!
•Your heart beats about 100,000 times in one day and
about 35 million times in a year.
•During an average lifetime, the human heart will beat
more than 2.5 billion times.
•Even at rest, the muscles of the heart work twice as hard
as the leg muscles of a person sprinting
• In one day, the blood travels a total of 19,000
km. That's 4 times the distance across
CANADA from coast to coast.
•When you are resting, it takes 35-40
seconds for the blood to move through
your body. What about when you are
exercising?
• approximately 10 seconds
•How much does your heart weigh?
only 2/3 of a pound!
• Give a tennis ball a good, hard squeeze.
You're using about the same amount of force
your heart uses to pump blood out to the body
Taking a Closer Look at the Heart
• The heart pumps blood throughout the body.
• The heart has four chambers:
 Left atrium
 Blood arrives from your lungs
 Right atrium
 Blood arrives from your body
 Left ventricle
 Pumps blood to your body
 Right ventricle
 Pumps blood to your lungs
• Between each of these chambers is a valve.
See page 84
(c) McGraw Hill Ryerson 2007
The human heart has 4 well developed chambers
Right Atrium
Left Atrium
Right Ventricle
Left Ventricle
Taking a Closer Look at the Heart
(c) McGraw Hill Ryerson 2007
The Circulatory System
• Starting with the right atrium, try placing the following
structures in the correct order that blood flows
through the body.
 Left ventricle
 Right atrium
 Lungs
Body
Left atrium
Right ventricle
(c) McGraw Hill Ryerson 2007
The Circulatory System
• The circulatory system moves blood throughout the
body.
See pages 85 - 86
(c) McGraw Hill Ryerson 2007
The Circulatory System
• There are three types of blood vessels:
 Arteries
 Carry oxygenated blood away from your heart
 Capillaries are tiny blood vessels
 Responsible for transfer of
oxygen and nutrients into the body
cells and collecting waste
from the cells.
 Veins
 Blood containing waste
products returning to the heart.
(c) McGraw Hill Ryerson 2007
The Circulatory System
(c) McGraw Hill Ryerson 2007
The Major Blood
Vessels of the Body
• The aorta, the largest artery in
the body, is almost the diameter
of a garden hose.
• The aorta in a blue whale is so
big, you could swim down it!!!
• Capillaries, on the other hand, are so small
that it takes ten of them to equal the thickness
of a human hair.
• One pound of excess fat adds approximately 200
miles of extra capillaries. This increases BP!
•If you stretched your veins out, and hooked
them all together, they would go around the world
2 times!!
The Components of Blood
• About 55% of blood is a liquid called
plasma.
 Contains proteins, minerals, and other
substances.
• Red blood cells carry oxygen from the
lungs to the cells.
• White blood cells fight infection.
• Platelets are important for clotting
blood.
See pages 88 -89
(c) McGraw Hill Ryerson 2007
(c) McGraw Hill Ryerson 2007
The Respiratory System
• The respiratory system moves oxygen into your body
and carbon dioxide out of your body.
See page 90
(c) McGraw Hill Ryerson 2007
The right lung is slightly larger than
the left.
Hairs in the nose help to clean the air
we breathe, as well as warming it.
The highest recorded "sneeze speed"
is 165 km per hour.
The surface area of the lungs is
roughly the same size as a tennis
court.
The capillaries in the lungs would extend 1,600
kilometres if placed end to end.
We lose half a litre of water a day through breathing.
This is the water vapour we see when we breathe onto
glass.
A person at rest usually breathes between 12 and 15
times a minute.
The breathing rate is faster in children and women than
in men.
The Respiratory System
• When you inhale, air is filtered by tiny hairs called cilia.
• Air passes through your larynx and continues down
your trachea towards your lungs.
• At the base of the trachea are two tubes called
bronchi.
• Bronchi branch into smaller air tubes called
bronchioles.
(c) McGraw Hill Ryerson 2007
This is the common passageway for air and food
This is a flap of tissue that covers the top of the
trachea when swallowing to ensure that food enters
the esophagus and not the lungs.
When the epiglottis is
opened, the air is able to
pass through the larynx
(voice box) and into the
trachea.
The larynx contains the
vocal cords (two tendons
that adjust the pitch of
sounds according to how
taut they are).
When a guy goes
through puberty, his
vocal chords and voice
box (larynx) grow larger,
and begins to stick out
at the front of the throat.
This lump is called the
Adam's Apple.
This is the windpipe.
This passageway is
held open by the
presence of C-shaped
rings of cartilage.
This is a protective
adaptation.
The trachea conducts
air into the bronchi.
•Cilia and mucus filter the
air as it moves through the
trachea.
•The mucous traps the dirt
and other particles, and the
cilia push it to the back of
the throat so we swallow it
into our digestive system
The trachea splits into
two bronchi and
takes the air into
each lung.
These branches also
have cartilage around
them, for the same
reason.
The bronchi conducts
air into smaller
branching
passageways called
bronchioles.
The bronchioles
are branching
passageways
that carry air
to its ultimate
destination,
the alveoli.
Gas Exchange in the Alveoli
• There are millions of alveoli at the
ends of the bronchioles, and this
is where gas exchange takes
place.
• Oxygen and carbon dioxide move
back and forth between the alveoli
and the surrounding blood
vessels.
See page 91
(c) McGraw Hill Ryerson 2007
Why are they so special?
1. Each adult lung
contains millions of
alveoli. This provides
lots of surface area for
the gases to be
exchanged.
2. The walls of alveoli are
only one cell thick.
3. They have stretch
receptors that signal
when the alveoli are
full enough (stretched).
They send a message
to the brain to start
breathing out.
This is a sheet of
muscle that
separates the
chest cavity from
the abdominal
cavity.
When you inhale it
moves down.
When you exhale it
moves up.
These are the bones that are connected to the
vertebral column and sternum.
These are muscles between the ribs, which help to
move the ribs…
1. Up and out when we inhale.
2. Down and in when we exhale.
See a Working
Respiratory
System:
http://www.smm.org
/heart/lungs/breathi
ng.htm
Smoking
• Smoking may cause both respiratory disease and
heart disease.
• Respiratory diseases could include emphysema and
lung cancer.
 Emphysema causes the alveoli walls to lose their
elasticity. This may make breathing very difficult.
• Smoking also destroys the cilia lining your respiratory
system.
See page 92
(c) McGraw Hill Ryerson 2007
SMOKING
POSTER
CHILD
http://www.tobaccof
acts.org/poster/inde
x.html
ANIMATION:
WHAT
SMOKING
DOES TO
YOUR BODY
http://www.mydr.com.a
u/default.asp?article=
4215
Take the Section 2.3 Quiz