Download 9.3 Natural Fluid systems

9.3 Natural Fluid systems
9.3 Natural Fluid Systems
• Many natural systems are based on fluids and
pressures
– Weather systems are created and influenced by barometric
pressure, measure with a barometer.
• Air pressure is measured in kilopascals (kPa)
or atmospheres (atm)
– Humans are affected by air pressures (breathing)
and fluid pressures (the circulatory and
respiratory systems)
• Water, and water balance, is vital for life
• The human body is 66% water, and
loses 2.1 L of water daily
(c) McGraw Hill Ryerson 2007
See pages 334 - 335
The Circulatory System
• The circulatory system is one of the most complex
hydraulic systems we know
– The heart is the pump, and blood vessels are specialized pipes
– Blood pressure refers to how hard blood pushes against the
walls of your body’s blood vessels
•
Nerve cells in the arteries monitor blood pressure
–
–
–
Your pulse is these waves of pressure
Normal resting heart rate is 60 - 100 beats per minute
Blood pressure is measured with a sphygmomanometer
which measures two different pressures
» Eg. Blood pressure = 120/75 mm Hg = two pressures
» 120 = heart pumping, and
» 75 = heart relaxing and filling with blood
See page 336
(c) McGraw Hill Ryerson 2007
Disorders of Blood Circulation
• Blood pressure is a part of normal check-ups, as
it is an indicator of overall health
– Like in all hydraulic systems,
roughness inside of pipes
decreases the hydraulic
system’s effectiveness
• Fatty deposits build up in
arteries to slow blood flow
– Smoking and obesity also
increase blood pressure
See page 337
www.nhlbi.nih.gov
(c) McGraw Hill Ryerson 2007
The Respiratory System
• Breathing is partly based on air pressure changes
– Air (and all fluids) normally move from high to low
pressure
– Inhaling expands the rib cage, increasing volume and
decreasing pressure
• The diaphragm and rib muscles expand your lungs
• Air from outside, which has oxygen in it, enters the low pressure in
the lungs
– Exhaling is the diaphragm and rib
muscles pushing inwards, increasing
pressure in the lungs so air leaves
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
• As the air leaves, it takes
unwanted carbon dioxide
See page 338
(c) McGraw Hill Ryerson 2007
Disorders of Breathing
• Breathing is affected by narrowed passageways,
especially swelling from infections and allergies
– Smoke, polluted air, coal dust and asbestos are also
harmful
– Asthma is a respiratory disease that narrows the
passageways for air entering and leaving the lungs
• Asthma can be triggered by smoke and pollutants, exercise,
stress and dust
• An inhaler is used to deliver tiny droplets of medicine to the
lungs to help passageways open
See page 339
(c) McGraw Hill Ryerson 2007
Take the Section 9.3 Quiz
Freeze! “High 5” Reading Checks
• How are blood vessels like pipelines?
• How is your circulatory system like a water
balloon?
• What are two causes of high blood pressure?