Gas Exchange and Transport Vocabulary Flashcards
total atmospheric pressure is the sum of the contributions of the individual gases
Dalton’s law
Partial pressure: the separate contribution of each gas in a mixture
Composition of inspired and alveolar air differs because of 3 influences:
- air is humidified by contact with mucous membraned
- air in alveoli mixes with residual air left from previous respiratory cycle
- alveolar air exchanges O2 and CO2 with blood
mixture of gases that exerts a pressure
Air
Each individual gas exerts its own pressure =
partial pressure
The higher concentration of a gas in the air, the _______ the partial pressure.
greater
at the air–blood interface (for a given temperature) the amount of gas that dissolves in the blood is determined by its solubility in blood and its partial pressure in air
Henry’s law
-The greater the PO2 in the alveolar air, the more O2 the blood picks up
What are some factors that affect efficiency of alveolar gas exchange:
- Partial pressure gradients
- Solubility of gases
- Respiratory membrane thickness
- Respiratory membrane area
- Ventilation-perfusion coupling
CO2 is ______ soluble than O2.
more
the ability to match air flow and blood flow to each other
Ventilation–perfusion coupling
According to ventilation-perfusion coupling, if there is increased blood flow there will be elevated PCO2 in alveoli, __________ of bronchioles and __________ airflow.
dilation of bronchioles and increased airflow.
According to ventilation-perfusion coupling, if there is decreased blood flow there will be reduced PCO2 in alveoli, __________ of bronchoiles and __________ airflow.
constriction of bronchioles and decreased airflow.
CO2 is a waste product of ________ respiration.
Aerobic
Oxygen leaves alveoli to go into the capillaries because the partial pressure of oxygen in the alveoli is ________ so it wants to diffuse _______ its pressure gradient.
high, down
CO2 wants to leave the capillaries and enter the alveoli because the partial pressure of CO2 is _______ in the capillaries and it wants to diffuse ______ its pressure gradient.
high, down
the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.
Surface tension
High surface tension in alveoli would cause collapse. Thats why alveoli require_______.
Surfactant
the process of carrying gases from the alveoli to the systemic tissues and vice versa
Gas transport
What 2 ways is oxygen transported:
- bound to hemoglobin in RBC (mostly)
2. dissolved in plasma
What 3 ways is CO2 transported:
- is hydrated to form carbonic acid (in RBCs)
- is bound to proteins in plasma and RBCs
- is dissolved as a gas in plasma
O2 bound to hemoglobin
Oxyhemoglobin
hemoglobin with no O2
Deoxyhemoglobin
the unloading of O2 and loading of CO2 at the systemic capillaries
Systemic gas exchange
What are the 3 fates of CO2 entering the blood:
- Dissolves
- Binds to plasma proteins (forms carbamino compounds)
- Enters red blood cells
- Binds hemoglobin (carbaminohemoglobin)
- Converted to carbonic acid (majority)
Carbonic anhydrase in RBC converts CO2 into Carbonic Acid. How does this happen.
CO2 binds to H2O which creates H2CO3 (carbonic acid). The carbonic acid is then converted to HCO3- (bicarbonate) and H+ (hydrogen ions).
After carbonic acid is converted to bicarbonate and hydrogen in the RBC, what happens?
Hydrogen is accumulated in the RBC. Bicarbonate is sent out via an anti-porter. This anti-porter also brings Cl- into the cell.
During CO2 unloading what happens?
The exact opposite process of carbonic anhydrase.
What 4 factors adjust the rate of oxygen unloading:
- PO2 (partial pressure of oxygen)
- Temperature
- active tissues has more CO2, which produces H+, weakening the bond between O2 and hemoglobin
- Bisphosphoglycerate (BPG)(fever, growth hormone, testosterone, and epinephrine)
low levels of oxyhemoglobin (hemoglobins carrying oxygen) enables the blood to transport more CO2
Haldane effect
