Respiratory System
Let’s find out how the body takes in oxygen and
keeps us alive!
Respiration is Breathing
• We can only go for a few minutes without breathing.
• Muscles around our lungs help us breathe because lungs are
NOT muscles.
• When we breath in we “inhale”
• When we breath out we “exhale”
Breathing through your nose is better than your mouth
• When we breathe through our nose three good things happen to the
air we take in:
– 1. The air is moistened from the mucus in our nose
– 2. The air is warmed from the mucus in our nose
– 3. The air is cleaned from the small hairs called cilia in our nose
• Our lungs like moist, warm, clean air!!
Gases we breathe in and out
• We inhale the oxygen our bodies need from the air.
• We exhale the carbon dioxide waste our bodies do not need into the
air.
• This process is called RESPIRATION!!
• The two main organs, the lungs, take in the oxygenated air.
• The diaphragm, a muscle under the lungs, help this process.
The parts of the Respiratory System
Nasal
Cavity
Nose
Mouth
Throat
(pharynx)
Wind Pipe
(Trachea)
Which is better to breathe through? The nose or the mouth?
More parts of the Respiratory System
Throat
(pharynx)
Voice box
(larynx)
Windpipe
(trachea)
Bronchi
Left Lung
Right Lung
Diaphragm
Inside the Lungs
Right Lung
Bronchial Tube
Air sac
(Alveoli)
MAGNIFIED
DIAGRAM:
Left Lung
Bronchi
Bronchial
Tubes
Respiratory System – Each part has a job!
Nasal Cavity
Nose
Cleans,
moistens
and warms
the air we
breathe.
Mouth
Can take in air
and helps do so
when we
breathe heavy
Produces
mucus
Throat (pharynx)
Nasal cavity
and mouth
meet here
Wind Pipe
(Trachea)
Takes air into lungs,
while helping to clean
the air as it goes down
More parts of the Respiratory System & their jobs
Throat (pharynx)
Nasal cavity and
mouth meet here
Windpipe
(trachea)
Takes air into lungs,
while helping to
clean the air as it
goes down
Voice box
(larynx)
Allows sound to be
created when air
passes over vocal
cords within our voice
box
Lungs
Lightweight organs
that take in oxygen
Bronchi
Two branches off
the trachea and
leading into the
lungs
Diaphragm
Muscle under lungs
that allow us to inhale
and exhale
Inside the Lungs
Right Lung
Bronchial Tube
The tubes inside
the lungs leading
to the air sacs
(alveoli)
Air sac (Alveoli)
The sacs where all air
ends up. Capillaries
surround all alveoli.
Alveoli have very thin
walls so the oxygen
can pass through &
get into our red blood
cells & CO2 can pass
out to be exhaled. We
have millions of
alveoli and they are
very small!
Lightweight, main
organ of the system
MAGNIFIED
DIAGRAM:
Left Lung
Lightweight, main
organ of the system. Do
you notice what side it
appears to be on in the
diagram? Remember
that a diagram is a
mirror image of your
actual body 
Bronchi
Two branches
off the trachea
and leading
into the lungs
Bronchial Tubes
The tubes inside
the lungs
leading to the air
sacs (alveoli)
Capillaries surround every Alveoli
The Diaphragm is an important muscle
• The Diaphragm is what allows our lungs to take in
Oxygen and release Carbon Dioxide.
• Our lungs could not do this on their own since they are
not muscles!
The Diaphragm helps us breathe!
• When we breathe out, the diaphragm moves upward, forcing the chest
cavity to get smaller and pushing the gases in the lungs up and out of
the nose and mouth.
• When we breathe in, the diaphragm moves downward toward the
abdomen, enlarging the chest cavity and pulling air in through the nose or
mouth.
Imagine your Diaphragm like a smile  or a frown 
• When you are breathing in oxygen your
diaphragm is smiling
and bends
downward to draw air into the lungs.
Imagine your Diaphragm like a smile  or a frown 
• When you are breathing out carbon dioxide
your diaphragm is frowning
and bends
upward to push against the lungs and squeeze
out the air.
Let’s watch this in action!!
• http://www.lungusa.org/site/pp.asp?c=dvL
UK9O0E&b=40743
PATH OF AIR THROUGH THE RESPIRATORY SYSTEM
Let’s write it out!
•
•
•
•
•
•
•
•
Nose or Mouth
Past the Pharynx
Past the Larynx
Down the Trachea
Into the Bronchi which take air into the LUNGS
Into the Bronchial Tubes
Into the Alveoli
Into our Red Blood Cells
What are some things that can damage our Respiratory System?
• Can you think of any?
• Smoking- damages your lungs and alveoli. It can lead to several harmful diseases
– Cancer: Lung, Liver, Mouth, & on & on
– Emphysema
– Bronchitis
• Pollution- makes the air we breathe less clean and can cause allergies and worsen
asthma if you have it.
Would you like to see a healthy lung and a smoker’s
lung?!?
• Can you tell who was the smoker?
THE END!
• Tell your neighbor 3 things you learned about the Respiratory
System.
• What are some affects on your respiratory system caused by
smoking?