Lecture 17

Question 1

2 methods of O2 delivery

Answer 1

Convection: O2 transfer by RBC through vessels
Diffusion: O2 transfer from high to low pressure

Question 2

VO2 convection equation

Answer 2

VO2= Q x a-vO2diff

Question 3

VO2 diffusion equation

Answer 3

VO2= DMO2 x (PO2cappillary - PO2mitochondria)

Question 4

What effect does low PO2 have on O2 offloading?

Answer 4

When PO2 is low, Hb’s affinity for O2 weakens, and offloads O2

Question 5

What is myoglobin?

Answer 5

-Protein in the muscle tissue that can store one O2 molecule
-Hb can deliver O2 to Mb
-Mb can hold O2 at low Po2

Question 6

3 factors affecting O2 diffusion (diffusive capacity)

Answer 6

1. Pressure gradient
2. Contact area between RBC and myocyte
3. Distance from capillary to mitochondria

Question 7

True or False: Myoglobin PO2 is affected by hypoxia

Answer 7

FALSE

Question 8

True or False: Training increases O2 diffusive capacity even if capillary PO2 remains unchanged

Answer 8

TRUE

Question 9

What is hematocrit? How does exercise affect it?

Answer 9

-Hematocrit is the ratio of RBC volume to total volume
-Exercise increases it, increasing RBC contact area, increasing diffusive capacity

Question 10

True or False: Exercise increases the body’s number of capillaries

Answer 10

TRUE