The human respiratory system has four important
structural features that enable it to function
properly:
 A thin permeable respiratory membrane through
which diffusion can occur
 A large surface area for gas exchange
 A good supply of blood
 A breathing system for bringing oxygen-rich air to
the respiratory membrane
Ventilation: the process in more complex organisms that ensures
a flow of oxygen-rich air to the lungs. (aka: breathing)
Gas Exchange: the processes whereby the body cells obtain
oxygen and get rid of carbon dioxide. (aka: diffusion of gases)
CILIA (in pink)
MUCUS
CELLS (in red)
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The oil in the machine of our body
We make about 1 – 1.5 litres per day
When sick, consistency changes (or from
dehydration)
Allergies (and some infections) cause leakage
of mucus producing cells
Green colour can be from neutrophils (most
abundant white blood cell in humans)
Alveoli
(air sacs)
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High Surface area
Air is 37oC and moist
Membrane is one cell thick
Passive Transport.
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Breathing is based on negative pressure
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http://www.youtube.com/watch?v=CBv2Bqq
AydE
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Pleura space (area between visceral and
parietal pleura) is filled with fluid to minimize
friction
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If air is introduced into the pleural cavity (ie:
through a stabbing or broken rib), the
membranes separate. This causes the lung to
collapse in a condition called pneumothorax.
If pneumothorax occurs, the lung cannot
inflate because nothing is pulling on it to
increase its volume and reduce its air
pressure. This leads to difficulty breathing.
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http://www.youtube.com/watch?v=isZzZ4TMnY
TOTAL LUNG CAPCITY:
TIDAL VOLUME:
The maximum volume of air that can be inhaled The volume of air inhaled or exhaled during a
during a single breath.
normal, involuntary breath. It's about 0.5L in
the average adult or 10% of the total lung
capacity.
INSPIRATORY RESERVE VOLUME:
EXPIRATORY RESERVE VOLUME:
The amount of additional air that can be
The volume of additional air that can be
inhaled after a normal inhalation.
exhaled after a normal exhalation.
RESIDUAL VOLUME:
The volume of air that remains in the lungs
after a forced exhalation. The residual volume
of air prevents the lungs from collapsing.
VITAL CAPACITY:
The maximum amount of air that can be
inhaled or exhaled. During periods of high
demand for oxygen the reserve volumes
decrease and tidal volume increases. The
maximum tidal volume is the vital capacity.
Vital capacity is about 4.4L to 4.8L in males
and 3.4L to 3.8L in females.
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Physical activity depends on the energy released during aerobic
cellular respiration which depends on the rate of oxygen delivery
a high maximum rate of oxygen usage indicates an efficient
respiratory system.
The rate of oxygen usage can be calculated using a spirometer.
VO2: It is an estimated or measured value representing the rate at which
oxygen is used in the body. It is measured in millilitres per kilogram
per minute (mL/kg/min)
VO2max: The maximum rate at which oxygen can be used in an
individual. It is the maximum amount of oxygen that an individual can
use during sustained, intense physical
activity. It is also
measured in mL/kg/min.
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EPO -- a hormone naturally produced by human
kidneys to stimulate red blood cell production
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http://www.youtube.com/watch?v=_3HVzBM
FcD8
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http://www.youtube.com/watch?v=7dG4b7Pz
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