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Unit 19: Biology Part 2 Page 58 of 137
harmful to you and keep them
from going any further into your
body and eventually reaching your
lungs.
Pharynx and Trachea
After leaving the nasal cavity, air
passes through the pharynx, a
long tube that carries both food Figure 38 – When you eat, the
and air. In everyday language, the epiglottis covers the trachea
pharynx would be referred to as (the tube on the left) so the
the throat. At the end of the food can go down the
pharynx is a flap of tissue called esophagus (the tube on the
the epiglottis. right.)
Have you ever been told not to talk Air travels down the trachea until it
and eat at the same time? Good gets to the lungs. You have a left
manners are not the only reason and right lung, so the trachea
for this. The epiglottis is part of divides into two tubes, one going
why this is a smart idea too. When into each lung. These tubes are
you are eating, the epiglottis called the left and right bronchi.
covers the trachea, or windpipe, Each bronchus (that’s the singular
which is a tube air is supposed to form of bronchi) branches out into
travel down. smaller tubes called bronchioles.
Bronchioles lead to alveoli. Trace
With the trachea covered, food can the path or air from trachea, to
go down the esophagus to the bronchus, to bronchiole, to alveoli
stomach. If food gets into the in the figure below.
trachea, it can cause coughing and
choking. If you talk or laugh while
you eat, you are more likely to
have the epiglottis unable to cover
the trachea, and therefore more
likely to choke.
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