Respiratory
System
Objectives:
1.
Describe the structure of the respiratory system.
2.
Analyze the function of the respiratory system.
Respiratory System
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Includes the nasal
cavity, pharynx,
larynx, trachea,
bronchi, alveoli,
lungs, and pleura.
Nasal Cavity
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Nasal Septum=divides
nasal cavities into R
and L sides
Cilia- the hairs in your
nose, trap larger dirt
particles.
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Sinuses- cavities in
the skull
Connected to the
nasal cavity, by ducts
Lined with mucous
membrane to warm
and moisten air
Sinuses give
resonance to the
voice.
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Pharynx
The throat
Common passageway for
air and food
5” long
When food is swallowed,
the Epiglottis closes
over the opening to the
larynx preventing food
from entering the lungs
Meet the Larynx
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Larynx- voice box
Triangular chamber
below the pharynx
Within the larynx are
vocal cords
Epiglottis covers larynx
during swallowing
Adam’s apple
Produces sound
Made of cartilage fibrous
plates
Meet the Trachea
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Windpipe.
4 ½ in. long.
Walls are alternate
bands of membrane and
C shaped rings of
hyaline cartilage to
keep trachea open and
more rigid
Lined with ciliated
mucous membrane.
Coughing and
expectoration gets rid
of dust-laden mucous.
Did Someone say Bronchi and Bronchioles are next?
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Lower end of
trachea divides into
R and L bronchus
Become bronchial
tubes and bronchioles
as braonches enter
lungs
Passageway for air
from trachea to
alveoli in lungs
Alveoli
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Clusters of thin-walled
sacs made of single
layer epithelial tissue
Inner surfaces covered
with Surfactant to keep
alveoli from collapsing
Each alveolus
surrounded by
capillaries
O2 and CO2 exchange
takes place between the
alveoli and capillaries
(diffusion)
Lovely Lungs
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Fill the thoracic cavity
Upper part=apex
Lower part=base
Lung tissue porous and
spongy –it floats
R lung=larger and shorter
displaced by the liver and
has 3 lobes
L lung smaller displaced
by the heart and has 2
lobes
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Pretty Pleura
Thin, moist slippery
membrane that
covers the lungs.
Double walled sac.
Space is pleural
cavity filled with
pleural fluid to
prevent friction.
Test your gray matter…..
What structure of
the respiratory
system is
responsible for
voice production?
Larynx
Which body
function is made
possible by
fibrous plates
contained within
the cartilage of
the larynx?
The respiratory
system ends in
millions of tiny,
thin walled sacs
called:
Alveoli
Pleura
Speech
The windpipe is
The wall of the
referred to as the: trachea are made
more rigid by the
presence of:
Trachea
Rings of
Cartilage
What covers the
outer surface of
the lungs and
lines the inner
surface of the rib
cage?
Each lung is
divided into two
or three parts
called:
Lobes
When the trachea
divides to enter
both lungs, the
tubes that are
formed are
called:
Bronchi

The partition that
separated the nose
into right and left
cavities is the:
Septum

The medical name
for the throat is the:
Pharynx
Function of the Respiratory System
1.
2.
External respiration,
internal respiration , and
cellular respiration
Production of sound
(vocal cords)
Pulmonary Ventilation (Breathing)
Inspiration Inhalation
Intercostal muscles lift
ribs outward,
sternum rises and
the diaphragm
contracts and moves
downward this
increases the volume
of the lungs and air
rushes in.
Pulmonary Ventilation
Expiration
Opposite action
takes place.
Exhalation is a
passive process
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Respiratory Movements
1 inspiration + 1
expiration=1
respiration
 Normal adult = 14-20
Respirations per minute
 Increases with
exercise, body
temperature, certain
diseases.
 Age-newborm= 4060/min
 Sleep= respiration 
 Emotion can  or 
rate
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Coughing
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Deep breath
followed by forceful
expulsion of air – to
clear lower
respiratory tract
Hiccups – spasm of
the diaphragm and
spasmotic closure
of the glottisirritation to
diaphragm or
phrenic nerve.
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Sneezing
Air forced through
nose to clear
respiratory tract
Yawning
Deep prolonged
breath that fills the
lungs, increases
oxygen within the
blood
Control Breathing
Breathing controlled by neural and chemical
factors.
Neural Factors
Chemical Factors
•Respiratory center
located in the Medulla
Oblongata
• on CO2 or  O2 in the
blood will trigger
respiratory center
•Phrenic Nervestimulates the diaphragm
Depends on the levels of
CO2 in the blood
(respiratory center in the
brain)
Chemoreceptors in aorta and
carotid arteries sensitive to
the amount of blood O2