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16 Cards in this Set
- Front
- Back
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what is the conducting zone?
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The conducting zone is the airways from the nasal cavity through the terminal bronchioles, that conduct air to the respiratory zones of the lungs.
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what is the respiratory zone?
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the lowermost part of the respiratory tract, contains the sites of gas exchange within the lungs.
The first respiratory zone structures are respiratory bronchioles, terminate in alveolar ducts, which lead to alveoli, |
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where does gas exchange occur?
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alveoli
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Why does gas exchange occure at alveoli
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Because only air spaces with sufficiently thin walls can participate in gas exchange.
The abundance of alveoli and capillaries facilitates the diffusion of gases. |
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what is pulmonary ventilation?
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exchange of air b/w atmosphere and lungs
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what is atmospheric pressure?
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Patm ) pressure of the outside air.
At sea level, atmospheric pressure is normally 760 mm Hg, |
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What is intra-alveolar pressure?
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pressure of air within the alveoli, at rest it is equal to atmospheric pressure, and thus is 0 mm Hg
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what is intrapleural pressure?
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pressure inside the pleural space.
At rest intrapleural pressure is -4 mmHg |
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What is transpulmonary pressure?
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difference b/w the intrapleural pressure and the intra alveolar pressure (Palv - Pip)
measure of the distending force across the lungs, such that an increase in transpulmonary pressure creates a larger distending pressure across the lungs and the lungs (alveoli) expand. |
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What creates changes in intra alveolar pressure?
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this is the answer: the quantity (moles) of air molecules in the alveolim and the vol. of the alveoli themselves.
varies during the phases of ventilation; in fact , the difference between intraalveolar pressure and atmospheric pressure is the pressure gradient that drives ventilation. When atmospheric pressure exceeds intra-alveolar pressure (when intra-alveolar pressure is negative), inpiration occurs; when intra-alveolar pressure exceeds atmospheric pressure ( when intra-alveolar pressure is postive), expiration occurs |
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what is the role of surfactant?
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decreases the surface tenison in alveoli.
surfactant interferes w/ the hyrogen bonding b/w water molecules. Therefore, sufactant increases lung compliance and decreases the work of breathing. |
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what cells secrete surfactant?
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type II alveolar cells loctated in the walls of alveoli.
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what are the 4 overlapping lung volumes measured using spirometry?
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overlapping
IC = inpiratory capcity VC = vital capcity FRC = fuctional residual capacity TLC = total lung capacity Non overlapping- Vt = tidal volume IRV = inspiratory reserve vol. ERV = Expiratory reserve vol. RV= residual vol. (cannont be measured) |
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what is minute ventilation?
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(Ve) is the total amount of air that flows into or out of the respiratory system in a minute.
Calculate as the tidal vol. x RR Ve = Vt x RR |
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What is the anatomical dead space?
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conducting zone of the respiratory tract; air in the region does not participate in gas exchange.
"old air" Has less O2 and more CO2 |
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what is alveolar ventilation?
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(VA) or minute alveolar ventilation) is a measure of the vol. of fresh air reaching the alveoli each minute.
VA = (VT x RR) - (DSV x RR) (dead space volume) |
