Lecture 6: Respiration Flashcards
List the four processes involved in respiration.
Pulmonary ventilation
External respiration
Gas transport
Internal respiration
Which of the following describes external respiration?
a. Exchange O2 and CO2 between alveolar air and pulmonary capillary blood
b. Exchange of O2 and CO2 between the systemic blood and the peripheral interstitial fluid.
c. Alveoli ventilated with fresh atmospheric air and removal of stale air from alveoli to atmosphere.
d. Transport of O2 and CO2 in the blood between the pulmonary capillary blood and the tissue.
a. Exchange O2 and CO2 between alveolar air and pulmonary capillary blood
The exchange of O2 and CO2 between the systemic blood and the peripheral interstitial fluid is which process?
a. Pulmonary ventilation
b. External respiration
c. Gas transport
d. Internal respiration
e. Internal ventilation
d. Internal respiration
Transport of O2 and CO2 in the blood between the pulmonary capillary blood and the tissue is which process?
a. Pulmonary ventilation
b. External respiration
c. Gas transport
d. Internal respiration
e. Internal ventilation
c. Gas transport
Which of the following is driven by simple diffusion (select all that apply):
a. Pulmonary ventilation
b. External respiration
c. Gas transport
d. Internal respiration
e. Internal ventilation
b. External respiration
d. Internal respiration
Which of the following is driven by the contraction of heart muscles?
a. Pulmonary ventilation
b. External respiration
c. Gas transport
d. Internal respiration
e. Internal ventilation
c. Gas transport
Approximately how many alveoli are in each lung?
300 million
Simple diffusion does not use ATP: true/false
TRUE
Simple diffusion does not use ATP
List three factors which influence the rate of movement of oxygen and carbon dioxide across the respiratory membrane of the alveoli.
Partial pressure gradients and gas solubility
Matching of alveolar ventilation with alveolar blood perfusion
Structural characteristics of the respiratory membrane (esp. thickness and surface area)
If the partial pressure gradient across the membrane is tripled, what will happed to the rate of gas exchange?
a. Doubled
b. x9
c. tripled
e. remains constant
c. tripled
If all other factors remain constant, halving the surface area of the respiratory membrane will ____ the rate of gas exchange?
a. Double
b. Halve
c. Not change
d. x4
c. Halve
If all other factors remain constant, halving the thickness of the respiratory membrane will ____ the rate of gas exchange?
a. Double
b. Halve
c. Not change
d. x4
a. Double
Pulmonary oedema will do what do the respiratory membrane?
a. Increase its surface area
b. Thicken
c. Decrease its surface area
e. Thin
b. Thicken
What determines the partial pressure of a gas?
% concentration x Atmospheric pressure
At sea level, what is the concentration of oxygen?
a. 79%
b. 35%
c. 13%
d. 21%
d. 21%
What is the atmospheric pressure at sea level?
760mm Hg
If atmospheric pressure at a given altitude is 680 mm Hg, what is the partial pressure of oxygen?
a. 160 mm Hg
b. 153 mm Hg
c. 143 mm Hg
d. 180 mm Hg
e. 104 mm Hg
c. 143 mm Hg
(.21 x 680)
160 mm Hg is the O2 partial pressure at sea level
Approximately what is the partial pressure of oxygen in the alveolar air?
a. 160 mm Hg
b. 153 mm Hg
c. 143 mm Hg
d. 180 mm Hg
e. 104 mm Hg
e. 104 mm Hg
What are the main differences between alveolar air and atmospheric air? What accounts for these differences?
Lower partial pressure of O2 (104mm Hg instead of 160 mm Hg) because O2 diffuses into the pulmonary blood and CO2 diffuses into the alveolar air.
More water vapor because moist internal linings humidify air.
What is the partial pressure of O2 in the blood arriving at the pulmonary capillary?
About 40 mm Hg
What allows O2 and CO2 to diffuse at the same rate across the respiratory membrane?
CO2 is 20x more soluble in plasma than O2, which compensates for the smaller partial pressure gradient.
O2 partial pressure in the alveolar air is 104 mm Hg, and 40 mm Hg in the blood arriving - a gradient of 64 mm Hg.
CO2 partial pressure in the alveolar air is 40 mm Hg, and 45 mm Hg in the mixed venous blood arriving at the pulmonary capillary.
What is the O2 partial pressure in:
a. Atmospheric air
b. Alveolar air
c. Mixed venous blood arriving at the pulmonary capillary
d. Blood leaving the pulmonary capillaries
e. The body’s interstitial fluid (at rest)
a. Atmospheric air: 160 mm Hg
b. Alveolar air: 104 mm Hg
c. Mixed venous blood: 40 mm Hg
d. Blood leaving the pulmonary capillaries: 104 mm Hg
e. The body’s interstitial fluid: 40 mm Hg
What is the CO2 partial pressure in:
a. Atmospheric air
b. Alveolar air
c. Mixed venous blood arriving at the pulmonary capillary
d. Blood leaving the pulmonary capillaries
e. The body’s interstitial fluid (at rest)
a. Atmospheric air: 0.3 mm Hg
b. Alveolar air: 40 mm Hg
c. Mixed venous bloody: 45 mm Hg
d. Blood leaving the pulmonary capillaries: 40 mm Hg
e. The body’s interstitial fluid: 45 mm Hg
Define internal respiration.
Diffusive transfer of O2 and CO2 between systemic capillary blood and body cell tissue.
