THE RESPIRATORY SYSTEM
Bleecker-ized for your Viewing
Pleasure
The Point of
Breathing
1. Oxygen is needed by our
cells to burn the fuel we
consume to walk,
breathe, see, hear, play
basketball, stay warm,
etc.
2. Our lungs use a process
called diffusion to
transfer oxygen from
high concentration to
low concentration in the
blood.
Of all the Elements, We Use Oxygen to
Chemically React with the Food in our cells
to produce Energy
Respiratory
System
How about a tour
of the system,
watch Mr. B click
the diagram to
jump to our tour

The Lungs contain Cilia to Clear
them Up
Head Region
Air enters the Mouth And Nasal Passages
where it is warmed & filtered
The brain stem controls breathing by CO2
concentration
Copyright © 2001 Benjamin Cummings, an imprint of Addison Wesley Longman, Inc.
Figure 10.13
Slide 10.8A
Regulation of Breathing:
Nervous System Involvement

Respiratory center in the medulla oblongata:
establishes basic breathing pattern

Medulla: sensitive to carbon dioxide in blood
informs the lungs to keep “breathing.”

Aorta in heart has sensors: sensitive to carbon
dioxide, and oxygen levels, telling the medulla to
tell the lungs to “breath.”

Conscious control: resides in higher brain
centers; ability to modify breath, hold breath, etc
Slide 10.8B
Breathing:Mechanical intake gas
Diaphram muscle expands & contracts the chest cavity
Human Respiratory System
Inside each lung, air moves into finer and finer
branchings called bronchioles. Their endings bear the
cup-shaped alveoli. The lungs have about 300 million
alveoli. Most often, alveoli are clustered as larger
pouches called alveolar sacs.
Trachea, Bronchi & Alveoli
Alveoli at Base of Lung
Pulmonary capillaries surround the alveoli. The
respiratory system's role in respiration ends at alveoli.
From that point on, the circulatory system takes over.
Oxygen and carbon dioxide move by diffusion between the
alveoli and the pulmonary capillaries around them.
Alveoli: Tiny air sacs
 Increase
Surface area
for gas
exchange
 Rich in
capillaries
 Over 700
million !
Human Respiratory System
Diagram of a section through an alveolus and the pulmonary
capillaries that surround it. The close-up view on the right
shows that the alveolar and capillary walls are separated by
only a narrow fluid-filled interstitial space. Oxygen diffuses
easily out of the alveolus, across the interstitial space, and
into the capillaries. Carbon dioxide diffuses in the opposite
direction.
Gas Exchange and Transport
This red blood cell is packed full of the respiratory pigment
hemoglobin. The structure of hemoglobin molecule is on
the right.
B. Comparing terms:
 Breathing:
Mechanical intake
and exhalation of gases (lungs)
 Respiration: the exchange of
gases by diffusion at the alveoli
 Cellular Respiration: Use of
oxygen by the mitochondria to
make ATP energy
Alveoli air sacs

Respiration or Gas
exchange at capillaries
 By the law of diffusion
 Blue blood low in
oxygen coming into the
alveoli
 Red blood high in
oxygen leaves the
alveoli
Cellular Respiration
 Breakdown
of
Food in the cell

in Mitochondria
 Plants & Animals
 Produces ATP
 Cell energy
 CO2 gas waste
Respiration is like a Campfire to
Burn Fuel to Do Work. The Fuel is
CHO or carbohydrates
C6H12O6+ O2 ----> CO2 + H2O + ATP (energy)
Essentially:




Eat  glucose for cells to run on
Burn glucose in factories (mitochondria)
Factory exports useable fuel called ATP for use
The burning releases water, just like when you burn a
log. It is a by-product. You see it when you breath out
on a cold day.
Lower Respiratory Tract
Functions:
 Larynx: maintains an open airway, routes
food and air appropriately, assists in sound
production



Trachea: transports air to and from lungs
Bronchi: branch into lungs
Lungs: transport air to alveoli for gas
exchange
Slide 10.4B
Vocal Cords, Open
Vocal cords, closed
Asthma – constriction
of the bronchioles 
What is Asthma?
1. Any reaction provoking a tightening or constriction
of the bronchioles
2. This reduces air flow to the alveoli, inducing a form
of suffocation
3. Treatment: Ventalin and other bronchio-dilating
medicines
Testing Vital
Capacity
VO2
The device above is called a Spirometer. It measures the total
volume of inhalation and exhalation, and determines the
VOLUME of the lungs.
Athletes normally have greater capacity. See the next slide.
Typical VO2 is 4 Litres. Leftover air is called Residual AIR
Vital Capacity determined by Heart
Rate during Exercise
Taking Care of Your Lungs


Smoking & Second Hand smoke
Diseases of the Lungs
Tuberculosis: Bacterial infection
Smoker’s Lung with tar deposits
Cancerous Lung
Whales have lungs……
Day2: A Closer Look at the Lungs
3 Lobes on right side
&
2 Lobes on the left
Adding up the Volume of the Lungs
1.
Tidal Volume
= normal volume of air moved in and out of lungs
~ 500ml
2.
Inspiratory Reserve Volume
= extra air our lungs can take in ~ 3100mL
3.
Expiratory Reserve Volume
= air we can breath out beyond the typical tidal volume
~ 1400mL
4.
5.
Vital Capacity = TIDAL + IR + ER
Dead Space
= parts of airpassages where air never reaches the lungs
Chemistry at the Alveolar Interface

H+ + HC03-1

CO2 carried by blood is converted into a
bicarbonate ion and water, so it can enter the
lungs where it dissociates into water and CO2
to be breathed out
Enzyme responsible for conversion
= Carbonic Anhyndrase

H2CO3
H20 + CO2
Hemoglobin Hb
1.
2.
Hb loses O2
Hb02
Hb + O2
H+ + HC03-1
H+ + Hb
H2CO3
O2 leaves blood!
H20 + CO2
HHb (purple)
Hb picks up a hydrogen and is reduced to HHb and
appears quite purple
3.
Much C02 travels in plasma as bicarbonate ions, in
addition to riding on Hb.
Respiratory Infections / Diseases
1.
2.
3.
4.
5.
6.
7.
Tuberculosis
Bronchitis
Strep throat / Rheumatic Fever
Pneumonia
Emphysema
Pulmonary Fibrosis
Lung Cancer
Tuberculosis

Bacterial infection by Mycobacterium
tuberculosis

Create calcified domes in the lungs and
walls itself off from the immune system

Heavy coughing ruptures the domes, which
causes bleeding
Tuberculosis: Bacterial infection
Bronchitis
Typically a viral infection
spread to sinuses, middle
ear, larynx and then
bronchi
Acute bronchitis usually is
caused by a secondary
bacterial infection
Strep Throat
•Strep throat is the most common
bacterial cause of sore throat
•can occasionally lead to
rheumatic fever, antibiotics are
given.
•Strep throat often includes a fever
(greater than 101 degrees
Fahrenheit),
•Signs  white draining patches
on the throat, and swollen or
tender lymph glands in the neck.
Children may have headache and
stomach pain.
What is Rheumatic Fever?

a heart condition in which
the heart valves are damaged
streptococcal bacteria

Rheumatic fever begins with
a strep throat from
streptococcal infection
Pneumonia
Viral/bacterial infection
of the lungs
The bronchi / alveoli fill
with fluid
Drowning-effect occurs
Emphysema

Emphysema is a condition in which the walls between the alveoli
or air sacs within the lung lose their ability to stretch and recoil.

The air sacs become weakened and break. Elasticity of the lung
tissue is lost, causing air to be trapped in the air sacs and
impairing the exchange of oxygen and carbon dioxide.

Early symptoms include shortness of breath and cough.
Symptoms of emphysema include shortness of breath, cough and a
limited exercise tolerance.
What causes it?

Cigarette smoking is by far the most common cause of
emphysema. Smoking is responsible for approximately 80-90%
of deaths .

In addition, it is estimated that 100,000 Americans living today
were born with a deficiency of a "lung protector" protein
Pulmonary Fibrosis

scarring of the lung. Gradually, the air sacs of the lungs become
replaced by fibrous tissue. When the scar forms, the tissue
becomes thicker causing an irreversible loss of the tissue’s
ability to transfer oxygen into the bloodstream.
Symptoms?






Shortness of breath, particularly with exertion
Chronic dry, hacking cough
Fatigue and weakness
Discomfort in the chest
Loss of appetite
Rapid weight loss
Causes?


Inhaling silica, coal dust, asbestos
Lungs cannot clear out these fibres
Cancerous Lung