23 Respiratory System Flashcards
What are the four processes of respiration?
-pulmonary ventilation
-alveolar gas exchange
-gas transport
-Systemic gas exchange
Boyle’s law
at a constant temp, pressure and volume are inversely proportional, as the volume of a container increases the pressures decreases and vice versa
P1V1=P2V2
Dalton’s law
the total pressure in a mixture of gases is equal to the sum of the individual partial pressures
The partial pressure of O2 at sea level: 760mmHg x 20.9%=159mmHg of O2
Henry’s law
at a given temperature the solubility of a gas in liquid is dependent upon the partial pressure and solubility
solubility in blood: CO2>O2>N
At a given temperature the solubility of a gas in liquid is dependent upon partial pressure and solubility. This is important because it tells us how easily a gas will diffuse into liquid, like blood. This is an additional complication to diffusion. We know based on diffusion a molecule will move from an area of higher concentration to a lower concentration and the greater the difference in concentration the greater the rate of diffusion. This complicates things because some gases will diffuse into liquid/blood more easily compared with others. For example, CO2 diffuses into liquid easily compared to O2 and nitrogen is practically insoluble. So, a small difference in concentration in CO2 results in about the same amount of diffusion as a much larger difference in concentration of O2. In the end we get about the same amount of O2 and CO2 being exchanged even with a different concentration gradient.
What percentage of oxygen is unloaded at the tissues (under normal conditions)?
20-25% (98% saturation leaving the lungs, 75% saturation in systemic cells at rest at sea level)
What are the types of passages found in the bronchial tree?
{bronchi contain smooth muscle and plates of hyaline cartilage so they remain open}
-main bronchi (primary) - where the trachea splits
-lobar bronchi (secondary) - extend to each lobe of the lung, 3 in right, 2 in left
-segmental bronchi (tertiary) - 10 in right, 8-10 in left
-smaller bronchi (levels 4 through 9-12) -
{no cartilage, layer of smooth muscle for bronchoconstriction and bronchodilation}
-bronchioles
-terminal bronchioles
{respiratory zone}
-respiratory bronchioles
-alveolar duct
-alveolar sacs (clusters of alveoli)
What forces are trying to collapse the lungs?
-inward pull of the elastic connective tissue of the lungs
-intrapulmonary pressure must be greater than intrapleural pressure, if they equalize the lungs will collapse
