Download The Respiratory System

The Respiratory System
Purpose of the respiratory
system
• To provide a constant supply of oxygen
to keep your body cells functioning
• To remove carbon dioxide from the
body cells
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Organs of the respiratory system
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Nose / mouth
Nasal cavity
Pharynx
Epiglottis
Larynx
Trachea
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Trachea
Bronchus (bronchi)
Bronchioles
Lungs
Alveoli
Pleura
Diaphragm
Mouth & Nose
• Brings air into the body
• Nasal hairs in nostrils trap dust
Nasal cavity
• Warms & moistens air
• Glands that produce sticky mucus line
the nasal cavity
– traps dust, pollen, and other materials that
were not trapped by nasal hairs
– cilia sweep mucus and trapped material to
the back of the throat where it can be
swallowed
Pharynx
• Tube-like passageway used by food,
liquid, and air
• At the lower end of the pharynx is a flap
of tissue called the epiglottis
– covers the trachea during swallowing so
that food does not enter the lungs
Larynx
• “Voice box”
• The airway to which two pairs of
horizontal folds of tissue, called vocal
cords, are attached
Trachea
• Air-conducting tube
• Connects the larynx with the bronchi
• Lined with mucous membranes and
cilia
• Contains strong cartilage rings
Bronchi
• Two short tubes that branch off the
lower end of the trachea
• Carry air into the lungs.
• Singular - bronchus
Bronchioles
• Tiny branches of air tubes in the lungs
• Connect bronchi to alveoli
Alveoli
• Tiny, thin-walled, grapelike clusters at
the end of each bronchiole
• Surrounded by capillaries
• Where carbon dioxide and oxygen
exchange take place
• Singular - alveolus
Gas Exchange Between Blood
and Alveoli
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Pleura
• Membrane lining the lungs and chest
cavity
Diaphragm
• Muscle wall between the chest and the
abdomen that the body uses for breathing
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Relationship to digestive system
• Cellular respiration requires
glucose and oxygen to release
energy to the body
• C6H12O6 + 6O2  6CO2 + 6 H2O + Energy
• Oxygen is provided by the respiratory
system
• Glucose is provided by the digestive
system
• (glucose is made during photosynthesis)
Upper Respiratory
Lower Respiratory
Regulation of Breathing
Lung Capacity
Breathing
Inspiration/Expiration: air in/air out
 Cycle:
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Relaxed state: diaphragm and intercostal muscles
relaxed
Inspiration: diaphragm contracts, pulling muscle
down, intercostal muscles contract elevating chest
wall and expanding volume of chest, lowering
pressure in lungs, pulling in air
Expiration: muscles relax, diaphragm resumes
dome shape, intercostal muscles allow chest to
lower resulting in increase of pressure in chest and
expulsion of air
Lung Function
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Lung volumes and vital capacity
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Tidal volume: volume of air inhaled and
exhaled in a single breath
Dead space volume: the air that remains in
the airways and does not participate in gas
exchange
Vital capacity: the maximal volume that can
be exhaled after maximal inhalation
Inspiratory reserve volume: the amount of air
that can be inhaled beyond the tidal volume
Lung Function
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Lung volumes and vital capacity
(continued)
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Expiratory reserve volume: the amount of
air that can be forcibly exhaled beyond the
tidal volume
Residual volume: the amount of air
remaining in the lungs, even after a
forceful maximal expiration
Measurement: spirometer