THE
RESPIRATORY
SYSTEM
C16L1
Part 2
glottis
the space
between the
folds
epiglottis
a thin,
flexible flap
in front of
the larynx;
folds over
and blocks
the glottis
during
swallowing
It keeps food and liquids from entering the
rest of the respiratory system.
Trachea (windpipe)
the tube that carries air between
the pharynx and the bronchi
trachea
It is held open by
C-shaped rings of
cartilage.
lined by the ciliated mucous
membrane which traps matter such
as dust, pollen, and smoke
ends behind the heart, where it
divides into 2 bronchi
bronchi
(singular,
bronchus)
the 2 branches
off of the trachea
leading into the
lungs
bronchi
function: carrying air to and from
the lungs
lungs
Lungs are the main
organs of the
respiratory system.
Inside the lungs,
the bronchi
continue to branch
into smaller and
narrower tubes
called bronchioles.
bronchi
bronchi
branch and
rebranch
to form
bronchioles
bronchioles
carries air to and from the alveoli
within the lungs
alveoli
(singular,
alveolus) the
microscopic
sacs in which
the exchange
of gases takes
place in the
lungs
alveoli
walls only 1 cell thick surrounded
by capillaries
How does this gas
exchange take place?
by diffusion
breathing
the process
of inhaling
and
exhaling air
diaphragm
Below the lungs is a
large muscle called
the diaphragm
that contracts and
relaxes and moves
air in and out of
your lungs.
breathing
diaphragm:
main muscle
used in
breathing
Secondary
muscles are
the
intercostals
Breathing and air pressure
 The movement of your diaphragm
causes changes in the air pressure
inside your chest.
 Air rushes into and out of the lungs
to equalize the air pressure inside
and outside the body.
Breathing and air pressure
 During inhalation, the diaphragm
contracts and moves down,
enlarging the space around the
lungs.
 During exhalation, the diaphragm
relaxes and moves up, reducing the
space around the lungs.
Breathing and air pressure