Transcript Respiratory System

Respiratory System:
A Breath of Fresh Air
What is Cystic Fibrosis?
• Hereditary disease affecting mucus glands of
lungs, liver, pancreas & intestines
• This recessive disease causes mucus buildup
in respiratory airways
• Leads to lung and sinus disease since
bacteria that normally inhabit the thick mucus
grow out of control and cause pneumonia.
• Leads to multisystem failure- although
patients usually die in the 20s and 30s due to
lung failure
• Lung transplantation is often necessary as it
gets worse
• In addition, people with CF often develop
clubbing of their fingers and toes due to the
effects of chronic illness and low oxygen in
their tissues.
Clubbed fingers
Fluids
• A fluid is a substance that has no defined
form and can flow in all directions. ALL
LIQUIDS AND GASES ARE FLUIDS!
• If fluids are compressible, their volume
DECREASES when a force is applied to it.
ex: gases, like air, are compressible
•If a fluid is incompressible, the
volume cannot be decreased by
adding force to it
ex: liquids, like water, are
incompressible
Air composition
Air is a fluid and it is a mixture of:
• 78% Nitrogen
• 21% Oxygen
• 1% trace gases, such as Argon, Neon,
Carbon dioxide, Helium, Methane,
Hydrogen and water vapor
Why do we need Oxygen?
• If the brain goes without oxygen for four
minutes, it can be permanently damaged.
• Oxygen is used for cellular respiration,
turning glucose into energy for the cells
(oxidation reaction!!)
Glucose + O2
CO2 + H2O + ENERGY
•When you exhale, you release
carbon dioxide and water vapor
Purpose of Respiratory
System
1) Provide the body with Oxygen
2) Provide a transfer site for Oxygen into the
blood stream to be circulated throughout the
body.
3) Eliminate Carbon dioxide from
the body.
Respiratory Airways
What do they do?
1. Take in air
2. Warm up and
moisten air
3. Remove foreign
particles from the air
Anatomy of the Respiratory
System
The 6 main parts:
1. Nasal Cavity
2. Pharynx
3. Larynx
4. Trachea
5. Bronchial tubes (Bronchi &
Bronchioles)
6. Lungs (Alveoli)
Nasal Cavity
Function:
• Filters, warms,
and moistens air
as it enters
• It also contains
FOUR SINUSES
Respiratory Defense…
… against Foreign Particles:
1. Nostril hair
2. Mucus in the respiratory
tract
3. Cilia in the trachea and
bronchial tubes
Pharynx
Function:
• Handles air
between nasal
cavity and
trachea
• Also contains the
Tonsils
Larynx
• Made of cartilage
• Also called the Adam’s Apple or voice box
because it holds the vocal chords
• The Epiglottis is found at the top of the
larynx
Trachea
• Function:
• Has cilia which filters
particles in the air.
Bronchial Tubes
• Made up of cartiliginous rings,
like the trachea
• Function: Filter particles in the
air.
Lungs
Function:
1. Remove Oxygen (O2) from the air and put it
into the bloodstream
2. Remove Carbon Dioxide (CO2) from the
bloodstream and release it into the
atmosphere.
Lungs
Function:
• Alveoli are thin, permeable sacs which are the
functional units of the lungs- this is where gas
exchange takes place.
• They are made up of a SINLGE LAYER OF
CELLS!
• There are 300 million in each lung!
Alveolar Network looks like an
upside down tree!
Gas Exchange
For this to happen, we need 2 things:
• Diffusion: movement from an area of higher
concentration of that substance to an area of lower
concentration.
• Selectively permeable membrane: a membrane
that only allows certain substances to pass
through.
Gas Exchange
Lower
concentration
of
CO2
Lower
Concentration of
O2
Selectively-permeable membrane
Clip: The Respiratory System
Breathing
Pressure and breathing
• When air pressure is low, it becomes more difficult
to breathe
• Pressure is the measurement of force exerted on
a surface
(P in pascals)=
Force (in Newtons)
Area of surface (in meters2)
1 N/m2 = 1 Pa
101.3 kPa = 760 mm of Hg = 1 atm
•Since air is made up of matter, it has
mass and can exert force
•The fewer air particles, the less force
is exerted, the smaller the air pressure
•This makes it hard to breathe
• Relationship between Pressure and
applied Force : As the force increases,
pressure increases
• Relationship between Pressure and
Area: As area increases, pressure
decreases
Bed of Nails!!
Back to Fluids…
• Compressible fluids, like air, can decrease in
volume when pressure increases. This is because
force increases.
• Fluids like to move from areas of high pressure to
areas of low pressure.
• Think of what happens when you breathe: inhaling
causes a decrease in pressure, allowing air to
enter lungs
• Exhaling causes an increase in pressure, pushing
air out
You are squeezing the particles of air
closer together every time you exhale
Mechanism for inspiration (inhaling)
and Expiration (exhaling)
Inspiration
Expiration
Intercostal muscles
contract, ribs move out and
up
Diaphragm contracts,
moves down
Intercostal muscles relax,
ribs move in and down
Volume of chest cavity
(thorax) and lungs
increases
Intrapulmonic pressure
decreases causing air to
enter lungs
Volume of chest cavity
(thorax) and lungs
decreases
Intrapulmonic pressure
increases, causing air to
exit lungs
Diaphragm relaxes, moves
up
Tobacco
Effects:
• Deterioration of the respiratory
system resulting in diseases
such as bronchitis and
emphysema.
• Cardiovascular diseases
characterized by damage to the
heart and blood vessels.
Tobacco
Changes in blood composition:
• Level of carbon monoxide,
a toxic gas, increases- it
binds readily with red blood
cells, thus a loss of binding
sites for O2 so
transportation of O2 to the
cells is greatly reduced.
And…
Lung Cancer
• Estimates suggest that
tobacco causes at least
40% of all types of
cancer and at least
90% of all cases of
lung cancer
• Bottom line: Tobacco
reduces life
expectancy
Smoking and pregnancy
Essentially, what the woman
breathes, so does the baby.
• So it can cause:
• stillbirths,
• premature babies,
• spontaneous abortions
• low weight babies
• And neurological damage
Air pollutants
•
•
•
•
Carbon monoxide.
Insecticides
Gasoline fumes
Sulphur dioxide =
acid rain
• Dust particles,
soot and sand,
can clog the
alveoli as well.
Improving Air Quality
1. Reduce the emissions of
pollutants through legislation
and the imposition of harsh
fines.
• Ban smoking in public
spaces and tougher
regulations for industry
2. Expand the number of green
spaces in cities and protect
those already in place.