chapter 23 part 2 Flashcards
ventilation
- definition
- atmospheric pressure
air will flow from high pressure areas to low pressure areas
-760 mmHg
before inspiration: interpleural pressure
- always negative or positive
- what does this do
- ___mmHg
- negative
- keeps lungs open
- 759 mmHg (-1 mmHg)
Before inspiration: interpulmonary pressure
760 mmHg
Inspiration
- chest width
- chest depth
- chest vol
- according to boyle law
- interpleural pressure
- air pressure is ___ than outside than in so air flows __
- increase
- increase
- increase
- increase in vol = decrease in pressure
- 759 mmHg (-1 mmHg)
- higher; in
end inspiration
air pressure inside = air pressure outside
expiration
- chest width
- chest depth
- chest vol
- according to boyles law
- intrapulmonary pressure
- air pressure is ___ inside than out, so air will flow __
- decrease
- decrease
- decrease
- decrease in vol = increase in pressure
- 761 mmHg (+1 mmHg)
- higher, out
gas exchange
- where does it occur
- what is it due to
occurs across the respiratory membrane and across capillary walls between blood and other tissues
-due to pressure gradients
dalton’s law of partial pressure
- total pressure of a gas mixture is…
- partial pressure
- atmospheric pressure
- the sum of the pressures exerted by each gas
- pressure exerted by a single gas in a mixture
- pN2 + pO2 + pCO2 + pH2O = P
formula for partial pressure
Partial pressure of gas A = total atmospheric pressure due to all gases X % of atmospheric pressure composed of gas A
Room air
- pO2
- pCO2
- 160 mmHg
- 0.3 mmHg
gas exchange between alveolus and alveolar capillary
- pO2 = 40; pCO2 = 45
- pO2 = 100; pCO2 = 40; alveolar air contains more ___
- pO2 = 100; pCO2 = 40
- deoxygenated blood coming from pulmonary circuit
- incoming air mixes with air remaining in the lungs after last breath; contains more CO2 and less O2 room air
- oxygenated blood goes to left side of the heart and systemic circuit
when does blood equalibrate with alveolar air
when pO2 = 100 and pCO2 = 40
interstitial fluid and systemic capillary
- pO2 = 95; pCO2 = 40
- pO2 = 40; pCO2 = 45
- pO2 = 40; pCO2 = 45
- systemic capillary carrying oxygenated blood
- cells consumes O2 and produce CO2 (increase in CO2 and decrease in O2 in tissues)
- deoxygenated blood in systemic capillary
when does blood equalibrate with the tissues
pO2 = 40 and pCO2 = 45
5 principles affecting the efficiency of gas exchange
- differences in partial pressure across the respiratory membrane are substantial
- distances involved are short (~0.5 um)
- Gases are lipid soluable
- total surface area is large
- blood flow and airflow are coordinated
greater the distance=
the faster the rate of gas exchange
what can easily diffuse across plasma membrane
gases because they are lipid soluable
large surface area =
more efficient gas exchange
what do blood flow and airflow play a role in
maximizing efficiency of both pulmonary ventilation and pulmonary circulation
oxygen
- 100 ml of blood contains ___ ml of O2; %
- ___ is dissolved in plasma
- ___ are bound to hemoglobin
- 20; 20%
- ~1.5%
- ~98.5%
hemoglobin saturation
- definition
- formula
- what will determine the direction of the reaction
- % of heme units containing bound to O2
- Hb+O2 ->
hemoglobin
- pO2 = 100 mmHg
- pO2 = 70 mmHg
- pO2 = 40 mmHg
- pO2 = 20 mmHg
- pO2 = 10 mmHg
- pO2 = 0 mmHg
- 99%
- 98%
- 75%
- 35%
- 10%
- 0%
the oxygen-hemoglobin saturation curve
- definition
- ___% of Hb is
- ___% represents
- is all O2 released in tissues; what does this generate
- change in pO2 produces
graph that relates the saturation of Hb to pO2
- 75%, oxyhemoglobin in the tissues
- 25%; O2 that has been released in tissues
- no; a reserve of O2
- large changes in amount of O2 released from Hb
hemoglobin undergoes what
-what does this promote
a change in shape each time it binds an O2
-the binding of additional O2