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
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
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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
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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)