Major Functions of the
Respiratory System
 supplies the blood with
oxygen which is then
delivered to all of the
bodies trillions of cells
 Removes Carbon Dioxide
from the blood and expels
it from the body
Why do we need Oxygen?
 Oxygen (O2) is an essential gas
in cellular respiration. This
process generates ATP (energy
molecules) in the mitochondria
of all cells.
 The primary waste product
generated by cellular respiration
is carbon dioxide (CO2)
The air we breathe
Divisions of the Respiratory Tract
• Upper Respiratory Tract
• Lower Respiratory Tract
Upper Respiratory Tract
• Nose
• Pharynx
• Larynx
Nose Functions
• Nasal vibrissae (hairs) filter the air of
impurities
• 3 turbinates warm and moisten air and serve
as mucus trap for remaining particulates.
• Special epithelium in nose makes olfaction
(smell) possible.
Respiratory System Organs:
Mouth, Nose, and Larynx
 When air enters your
mouth/nose, mucus aids in
humidifying and warming
the air before it enters your
lungs.
 It passes over your larynx,
or voice box, which has
vocal folds able to generate
sound. The larynx also
protects the trachea.
Larynx
• Voice box
• Also shape of the nose, mouth, pharynx, and
bony sinuses help determine the quality of the
voice.
• Protects airway from entrance of solids and
liquids during swallowing.
Challenge Question!
 When you sneeze particles fly from your
nose and mouth at nearly 100 mph!
What is the
physiologic reason
why one would
need to sneeze?
Respiratory System Organs:
Pharynx and the Epiglottis
 In the back of the throat, the
place where the nasal cavity
and the oral cavity meet is
called the pharynx.
When you eat, a flap of
connective tissue called the
epiglottis prevents food
from entering the trachea.
Pharynx Functions
• Also called the throat
• Common pathway for food and air
• Functions in producing vowel sounds for
speech
Lower Respiratory Tract
• Trachea
• Bronchi
• Alveoli
Respiratory System
Organs: The Trachea
 The trachea, or
windpipe, is a tube
made of cartilage rings
that branches into 2
bronchi. It is lined with
cilia and mucus
designed to filter
harmful particles from
the air we breathe.
Trachea Functions
• Carries air from outside the body to the lungs,
and from the lungs to outside the body.
• Contains c-shaped rings of cartilage to prevent
collapse of the airway.
Respiratory System Organs:
Bronchi and Bronchioles
 The trachea opens
into 2 bronchi and
then continues to
branch into smaller
and smaller tubes
called bronchioles.
Gas exchange does
NOT take place
here…
Bronchial Histology
Common Feature
• Almost the entire respiratory tract is covered
in a mucus layer called respiratory mucus.
• Associated with the mucus is ciliated
pseudostratified epithelium.
Bronchi and Alveoli Functions
• Primary bronchi enter lungs on each side
– Secondary bronchi
– Tertiary bronchi
– Bronchioles continue to branch into smaller tubes
(alveolar ducts) that dead end into the alveoli
• Bronchi are responsible for carrying air
through lungs to alveoli
Bronchi and Alveoli Function
• Alveolar sac resemble grapes on a stem
– Stem – alveolar duct
– Grape- alveolus
Bronchial Epithelium
 Clumps of hair-like cilia
protrude from the tops of
specialized columnar
epithelial cells. Rhythmic
movements of the cilia serve
to move bacteria and other
particles away from alveoli
and towards the throat, where
they are expelled or
swallowed.
scanning electron
micrograph (SEM) of
bronchial epithelium (the
mucus membrane lining
the major airways of the
lung).
Lung Tissue Histology
 The alveoli are composed of a
single layer of squamous
epithelium. Between the alveoli
you may see a thin layer of
areolar connective tissue and
numerous capillaries also lined
with simple squamous
epithelium.
Respiratory System
Organs: Alveoli
 The bronchioles terminate in tiny saclike structures called “alveoli,” O2 and
CO2 are exchanged here in microscopic
blood vessels called capillaries.
Inside and Alveoli
Capillary
 The average
individual has
approximately
700 million
functional
alveoli.
Wall of
the air
sac
Carbon
Dioxide is
dropped off
Oxygen is
picked up
Red Blood
Cell
MB
Bronchi and Alveoli Function
• Alveoli wall (respiratory membrane) is simple
squamous epithelium and is direct contact
with blood vessel capillaries.
• This is where gas exchange occurs.
• The fluid inside each alveolus contains
surfactant which keeps alveolus from sticking
shut as moves in and out.
Inside and Alveoli
(cont)
C
A
B
Can you Identify
these structures?
Inside and Alveoli
(cont)
C
A
B
What tissue has
been removed in this
image? What do the
black lines represent?
In Summary…
Cool pictures
JH
Did you Know?...
The surface area of the lungs is
roughly the same size as a tennis
court!
Did You Know?...
 A “Yawn” occurs when a
person’s blood contains
elevated levels of carbon
dioxide. the influx of
oxygen provided by the
yawn helps re-establish
homeostasis.
Respiratory System
Organs: The Pleura
 The pleura, or pleural
cavity, is a fluid filled
double membrane that
surrounds the lungs. It
effectively creates a
closed space (like a
balloon) for the lungs to
operate.
The Lobes of the Lungs
Did you know?
 Chemicals in cigarette smoke damage
alveoli.
Normal lung
Smokers lung
The Circulatory System and
the Respiratory System
 The primary vehicle
for gas exchange is
the red blood cell.
These cells have a
protein called
hemoglobin, which
attach to and release
respiratory gases.
Hemoglobin: A Closer Look
The Circulatory System and
the Respiratory System
 Blood is delivered to the
lungs via the heart in a
process called
“pulmonary circulation.”
Oxygenated blood is then
transported back to the
heart, and pumped to all
of the bodies tissues.
Respiratory System
Organs: The Diaphragm
 The diaphragm is a large
muscle that separates the
abdominal and thoracic
cavities. When you inhale,
it moves downward and
your ribcage expands.
When you exhale it returns
to its normal position and
air is expelled from the
lungs.
Using a
Spirometer:
Factors affecting volumes
Several factors affect lung volumes;
some can be controlled and some cannot.
Lung volumes can be measured using the following terms:
Larger volumes
Smaller volumes
males
females
taller people
shorter people
non-smokers
smokers
athletes
non-athletes
people living at high
altitudes
people living at low altitudes
Average forced
lung capacity:
Male: 4.6 Liters
Female 3.5 Liters
Chronic Obstructive
Pulmonary Disease
 Emphysema is a lung
disease involving
damage to the air sacs
(alveoli).There is
progressive destruction
of alveoli and the
surrounding tissue that
supports the alveoli.
Non-Respiratory Functions
 Exhalation provides a route
for water loss and heat
elimination.
 Helps regulate blood pH
 Enables speech
 Defends against inhaled
foreign material/pathogens.
 Smell
Bronchitis
Asthma
Fun Facts!
 At rest, the body takes in and breathes
out about 10 liters of air each minute.
 The right lung is slightly larger than the
left.
 The capillaries in the lungs would extend
1,600 kilometers if placed end to end.
 We lose half a liter of water a day through
breathing. This is the water vapor we see
when we breathe onto glass.
 A person at rest usually breathes
between 12 and 15 times a minute.
 The breathing rate is faster in children
and women than in men.
Did you know….
 David Blaine set a new
world record for breathholding on April 30,
2008, at 17 minutes,
4.4 seconds, during a
live telecast of The
Oprah Winfrey Show.

Pop Quiz!
 Can you
identify
structures 1-6?
Pop Quiz #2
(easy)
Fill in the Blank
1. Burning fuel (food) requires __________
2. All living things carry out _________.
3. 2 waste products generated by cellular respiration include water
and _______.
4. Small blood vessels where gas exchange occurs: ________
5. Cilia and mucus help moisten and _______ the air we breathe.
6. Another word for “windpipe” __________
7. Another word for “voice box” _________
8. Air sacs in your lung where gas exchange takes place:
_________
9. The respiratory system works most closely with this body system:
__________ ___________.
10. This tiny structure prevents choking when you eat. __________
Pop Quiz #3 (harder)
Fill in the Blank
1.
2.
The formula for cellular respiration is: ___________________________________
________ protrude from the tops of specialized columnar epithelial cells in
bronchioles.
3. _______ is the functional component within hemoglobin protein molecules.
4. Expansion of the ribcage generates _________ __________, forcing air into the
lungs.
5. The alveoli are composed of a single layer of __________ _________.
6. Mast cells generate __________.
7. ___________ __________ protects the larynx.
8. ___________ __________ delivers blood to and from the lungs from the heart.
9. Smoking can cause Chronic Obstructive Pulmonary Disease, or ____________.
10. The atmosphere is composed of 79% diatomic __________ and 20% diatomic
__________.
11. The _________ _________ is a fluid filled double membrane that surrounds the
lungs.
Lung capacity and volume

Total lung capacity




Tidal volume
Inspiratory reserve
Expiratory reserve
Residual air
Sample
2.06 Understand the functions and disorders
of the respiratory system
50
#11 DISORDERS of the
Respiratory System
Boy, what an important set of organs for your survival. No wonder
you can hold your breath only so long before your body says, “enough,
you’re being foolish” and forces you to breathe despite your efforts.
So, take care of your respiratory system. Seriously. Let’s see what can
happen if it doesn’t function properly or if you abuse what you were
given.
I don’t like how this
sounds…what are
you gonna do to me?
Let’s say that Joe has been a chain-smoker for many years…
#12 Disorders, contd.
Smoking kills little hairs in
your respiratory tract that
move mucus around. This
causes that annoying
“smoker’s cough” that you
often hear. It causes an
extreme shortness of breath
called emphysema, which
would affect your daily life.
And of course, it often
leads to…
#13 Disorders, contd.
Man, I’m tired. I’ve
gotta take a break.
Smoking is probably the most
harmful way in which you can
damage your respiratory system
on purpose. Avoiding its problems
is easy…just don’t start. It
might’ve seemed cool &
rebellious 20 years ago, but now
most people realize it’s just dumb.
Let’s give Joe a break—he kicks
the habit. 
Respiratory disorders


Bronchitis: inflammation of
mucous membrane of trachea
and bronchial tubes that
causes excess mucus
What is bronchitis?


Acute: spreading inflammation
from nasopharynx or inhalation of
irritants (cough, fever, substernal
pain and rales—raspy sound)
Chronic: mid-old age (severe and
persistent cough with large
mounts of discolored sputum)
2.06 Understand the functions and disorders
of the respiratory system
54
Respiratory disorders

Asthma
What is asthma? Airway becomes
obstructed because of an inflammatory
response to a stimuli
Who most likely has it? Allergen or
psychological stress
Symptoms: exhaling, wheezing,
dyspnea & tightness in chest
2.06 Understand the functions and disorders
of the respiratory system
55
#15 Disorders, contd.
2. Asthma – there are lots
of causes of asthma,
and some pretty easyto-use treatments. Asthma
occurs when your
bronchial passages
inflame, causing them to
shrink up and make
breathing difficult.
#16 Disorders, contd.
One condition that genetic researchers are still trying to cure is called:
3. Cystic Fibrosis – This is a build-up of thick mucus in the lungs…this
mucus must be loosened and coughed up very often. Cystic Fibrosis
is genetic, and appears almost instantly in newborns. The problems this
mucus causes the lungs and digestive system usually results in pretty
serious health concerns as the people enter their 20s and 30s.
Respiratory disorders



Chronic obstructive pulmonary disorder
Chronic Bronchitis, emphysema, and
asthmatic bronchitis
Obstruction of airflow
SMOKING!!!!!
2.06 Understand the functions and disorders
of the respiratory system
58
Respiratory disorders

COMMON COLD



What is it? Runny nose, cough, sneezing, stuffy head,
sore throat
What causes it? Hundreds of different strains of
viruses
Hand-washing – best preventative
measure
2.06 Understand the functions and disorders
of the respiratory system
59
Respiratory disorders

Emphysema
What is emphysema?
Alveoli become overdilated, loses
elasticity, and cannot rebound—
alveoli rupture, air becomes trapped
there and is difficult to exhale, reduce
exchange of O2 and CO2
Who is most likely to have it?
Smokers
How is it treated? Alleviate symptoms
(supplemental O2)
2.06 Understand the functions and disorders
of the respiratory system
60
Respiratory disorders
Influenza
Discuss the symptoms of
influenza.
FEVER, muscle
pain/fatigue, and mucus
discharge from nose and
cough

2.06 Understand the functions and disorders
of the respiratory system
61
Respiratory disorders

Pneumonia
• Viral or bacteria
• Alveoli filled with thick
fluid that has pus and
RBC’s
• Symptoms: chest pain,
fever, chills, and dyspnea
2.06 Understand the functions and disorders
of the respiratory system
62
Respiratory disorders

Pneumothorax: air in the chest cavity
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of the respiratory system
63
Respiratory disorders




Sinusitis: infection in the sinus
cavity
Many cavities may be infected
Pain and nasal discharge are
main symptoms
Use a humidifier, drink plenty of
fluids, warm moist cloth to face
several times a day
2.06 Understand the functions and disorders
of the respiratory system
64
Respiratory disorders

Tuberculosis
• Causes lesions in lungs
• Cases had been steadily
decreasing until recent years
due to increase homeless,
AIDS & illegal immigrants
• Treat with INH
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of the respiratory system
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That’s All
Folks!