O2 and CO2 Transport and Exchange

Question 1

Fick’s Law of Diffusion (& major point)

Answer 1

Vgas (rate of diffusion) = (A/T)Dgas(p1-p2)
A is area, T is thickness, Dgas is diffusion coefficient for that gas, and p1-p2 is partial pressure gradient.
*Gasses diffuse independently of one another

Question 2

Nonlinear Relationship of pO2 and Hb O2 Saturation

Answer 2

Cooperative binding gives you a an S shape with a long plateau at the end

Question 3

Reason for Extracting only 1/4 of O2

Answer 3

O2 reserve if tissues need more

Question 4

4 Factors that Reduce Hb’s Affinity for O2 (shift curve to right)

Answer 4

Increased CO2
Decreased pH
Elevated temp
2,3-BPG

Question 5

2,3-BPG

Answer 5

Substance in RBCs to release O2 in hypoxia. Donated blood loses this, so harder for it to unload O2

Question 6

Fetal Hb

Answer 6

Has higher affinity for O2 so it can get O2 diffusing from mother

Question 7

2 Dangerous Effects of CO

Answer 7

Blocks binding sites for O2 but also increases affinity of bound O2 decreasing unloading ability

Question 8

Dissolved O2 at Air and Enriched-O2 Environments

Answer 8

Normally negligible in air, but increases linearly w/ increased O2 so in O2-rich environments it can factor in greatly

Question 9

2 Ways to Extrude CO2 From Tissues (& something that happens w/ each)

Answer 9

Can either bind deoxy Hb to make carbaminoHb or (more commonly) combine w/ H2O to form HCO3- which is extruded from RBC via HCO3-/Cl- exchanger. Each produces a H+ that can bind reduced Hb serving as a buffer