Download or oral cavity

Don’t Smoke!
Emphysema
Lung Cancer
THE
PATHWAY OF
AIR
1. Nasal Cavity
(or oral cavity)
•Air enters the body
through the nostrils
(your nose) most of
the time
•It is lined with a
ciliated mucus
membrane which
filters, warms, and
moistens the air
2. Pharynx
•Where the oral cavity
(your mouth) and the
nasal cavity (your
nose) meet.
•When you breathe
through your mouth,
air enters the pharynx.
3. Trachea
• The main airway in
the human respiratory
system.
•It contains rings of a
tough tissue (cartilage)
which keep the trachea
open.
Larynx
•Also known as the voice
box.
•It is made of cartilage and
is located at the upper end
of the trachea.
•When air passes over it, it
vibrates. (hum so I know
you are reading this)
Epiglottis
•A flap of tissue
that covers the
trachea when
you swallow so
food doesn't
enter
Trachea
Esophagus
4. Bronchi
•Two tubes that branch
off the trachea.
•The bronchi are
ringed with cartilage.
•Each bronchus
extends to the lungs
where the tubes
become smaller.
5. Bronchioles
•Smaller and smaller
passageways that
extend from each
bronchus.
•The bronchioles are
found in the lungs and
not ringed with
cartilage.
6. Alveoli
•The lungs are made
of about 300 million
of these tiny air
sacs.
•When you breathe
in air fills the alveoli.
•Oxygen leaves the
alveoli, enters the red
blood cells and is
returned to the heart
to be pumped to all
your body cells.
•Carbon dioxide is
exhaled when you
breathe out.
Gas Exchange in the Alveoli
Exit Ticket: Choose one
• Summarize what you have learned today
• Why do we breathe?
• Why is smoking so dangerous for your
respiratory system?