Term
What are the 3 main functions of the ventilatory system? |
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Definition
1. Supply oxygen required in metabolism 2. Eliminate carbon dioxide produced in metabolism 3. Regulate hydrogen ion concentration to maintain acid-base balance |
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Term
What does the term pulmonary ventilation describe? |
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Definition
How ambient atmospheric air moves into and exchanges with ait in the lungs |
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Term
What does the conducting zone of the respiratory system do? |
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Definition
filters air humidifies it warms it |
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Term
What do the lungs provide a surface between? |
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Definition
the blood and the external environment |
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Term
How many aveoli are in lung tissue? |
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Definition
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Term
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Definition
elastic, thin-walled membranous sacs |
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Term
What are aveolis function? |
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Definition
provide the vital surface for gas exchange between the lungs and blood |
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Term
What tissue has the largest blood supply of any organ? |
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Definition
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Term
What is the respiratory membrane? |
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Definition
the single cell barrier in the pulmonary capillaries that seperates the blood from the air |
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Term
What does the thins tissue-blood barrier permit between aveolar and blood gases? |
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Definition
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Term
During rest how much oxygen leaves the aveoli and how much carbon dioxide enters them? |
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Definition
about 250mL and 200mL respectively |
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Term
What does any change in thoracic cavity volume produce? |
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Definition
A corresponding change in lung volume |
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Term
What changes the thoracic dimensions? |
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Definition
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Term
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Definition
a large dome shaped sheet of muscle that seperates the thoracic and abdominal cavities |
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Term
What happens when the diaphragm contracts? |
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Definition
it flattens out and moves downwards about 10 cm enlarging and elongating the chest cavity, so air rushes in |
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Term
Name the 2 factors that effect the degree of lung filling |
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Definition
1. magnitude of inspiratory movements 2. pressure gradient between air inside and air outside the lung |
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Term
What marks the end of inspiration? |
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Definition
When the thoracic cavity expansion ceases and intrapulmonic pressure increases to equal atmospheric pressure |
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Term
What inspiratory muscles are active during exericse? |
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Definition
the scalenes and external intercostals |
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Term
What do the scalenes and external intercostals cause during exericse? |
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Definition
they rotate and life the ribs away from the body |
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Term
What are the 3 factors that cause the chest cavity to expand? |
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Definition
1. descent of the diaphragm 2. upward lift the ribs 3. outward thrust of the sternum |
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Term
Expiration is predominantly what? |
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Definition
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Term
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Definition
elastic recoil of the lungs relaxation of the inspiratory muscles |
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Term
During exercise what muscles help expiration? |
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Definition
the internal intercostals abdominal muscles |
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Term
What is a spirometer used for? |
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Definition
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Term
What is the difference between static and dynamic lung volumes? |
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Definition
Static lung volumes evaluate the dimensional compnent for air movement with no time limitations, dynamic lung volumes measure the power component of the lungs with a time value |
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Term
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Definition
air moving in or out of the lungs in each breath |
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Term
What is the inspiratory reserve volume? |
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Definition
The amount of air above the tidal volume that can be brought into the lungs |
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Term
What is the expiratory reserve volume? |
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Definition
The amount of air that can be forced out of the lungs after normal exhalation |
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Term
What is forced vital capacity? |
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Definition
the total air volume moved in one breath from full inspiration to maximum exhalation |
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Term
What is residual lung volume? |
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Definition
the amount of air that remains in the lungs after maximal exhalation |
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Term
Why do lung volume decrease with age? |
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Definition
decrease in lung tissue elasicity and pulmonary muscle power but probably more inactive lifestyle |
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Term
What do dynamic lung volumes tell us? |
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Definition
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Term
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Definition
the percentage of FVC that can be expelled in 1 second |
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Term
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Definition
because normal tidal volumes can occur in people with severe lung disease |
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Term
What is maximum voluntary ventilation? |
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Definition
the amount of air that can be inhaled and exhaled in a certain time period |
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Term
What is the average breathing rate at rest? |
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Definition
about 12 breaths per minute |
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Term
What does minute ventilation equal? |
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Definition
breathing rate times tidal volume |
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Term
What is average tidal volume at rest? |
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Definition
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Term
What does aveolar ventilation refer to? |
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Definition
the portion of the minute ventilation that mixes with the air in the alveolar chambers |
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Term
What is the anatomical dead space? |
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Definition
The trachea, nose, bronchi, bronchioles etc where air enters but is not used in gas exchange |
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Term
What is physiological dead space? |
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Definition
The portion of the aveolar volume with poor tissue regional perfusion or inadequate ventilation |
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