Download The Respiratory System

The Human Body Lesson
The Respiratory System
The Function of the Respiratory
System
 The main job of the
respiratory system is to
take in oxygen and get rid
of carbon dioxide waste.
 The lungs are the major
organs of the respiratory
system.
The Diaphragm
 The lungs are controlled by
a flat, thin muscle called the
diaphragm.
 It is located under your
lungs.
 When the diaphragm pulls
down, it expands your
lungs, inhaling air.
 When the diaphragm
relaxes, it moves up,
exhaling old air.
Hiccups
The Diaphragm’s Evil Revenge!
 The diaphragm is also what
causes you to have hiccups.
 When you eat or drink too
much or too quickly, it
causes your stomach to
swell near the diaphragm.
 This causes it to become
irritated and move
erratically.
So ironic that a hiccup knocked
this baby goat down….get it?
hiccUP…and he fell down…never
mind.
Lobes of the Lung
 The left lung is smaller
than the right to make
room for the heart.
 The lungs are divided into
sections known as lobes.
 The left lung has two
lobes.
 The right lung has three
lobes.
Drawing of the
lobes of the lung
A human lobe
removed for
transplant.
The Journey of Air
 Air is taken in through either
your nostrils or mouth.
 Air passes through the
pharynx, the back of your
mouth.
 It then passes by the
epiglottis, a muscular flap
which directs food and air to
the right tubes.
 The epiglottis is what
prevents food from entering
your lungs.
In some people, you can actually see
their epiglottis poking out at the back
of their throat, but this is not
common.
The Journey of Air
 Thick bands of cartilage
form your “voice box” or
larynx.
 These bands of cartilage
are called vocal cords.
 When we talk, the cords
squeeze together. This
makes them vibrate and
make sound when we
push out air.
The Journey of Air
 Air then passes through
your trachea, which is
commonly called your
“windpipe.”
 The trachea is made of
several cartilage rings.
Let's take a quick
trip down the
trachea
Your trachea as
seen from the
inside. Notice it
branching into the
two lungs.
The Journey of Air
 Cilia are tiny hairs that are
found in your trachea and
bronchi. They help to remove
mucus.
 Gross Fact: Smoking paralyzes
the cilia, preventing them from
clearing junk out of your lungs
so it builds up all day long.
When a smoker wakes up in
the morning, the cilia are back
at work, bringing up all of the
mucus. This is why heavy
smokers cough so much in the
morning.
These are the cilia found in your
lungs. Yep, you have hairy lungs.
The Journey of Air
 The trachea then splits
into two main branches
called the bronchi.
 The bronchi then split
into hundreds of smaller
tubes called the
bronchioles.
 The pleura is a thin
membrane that covers
the lungs and helps to
lubricate them.
This illustration shows the bronchioles inside of the
lungs.
The Journey of Air
 Alveoli are tiny air sacs
Amazing photo
of the surface of
found at the ends of
bronchioles. This is where alveoli using an
oxygen and carbon dioxide electron
microscope!
are exchanged.
 Oxygen is taken in from the
air. We breathe out mostly
CO2 but some unused
oxygen as well.
 The blood then takes the It’s an extreme
close up view of
oxygen to the body and
this part!
returns with tired blood
filled with CO2