Oxygen Transport: Lecture 1

Question 1

When in the 4 steps of external respiration is O2 and CO2 being transported?

Answer 1

• Step 3: blood transport

Question 2

What are the 2 methods of gas transport in the blood for OXYGEN?

Answer 2

1. Physically dissolved
2. Bound to hemoglobin

Question 3

What are the 3 methods of gas transport in the blood for Carbon Dioxide?

Answer 3

1. Physically dissolved
2. Bound to hemoglobin
3. As bicarbonate (HCO3)

Question 4

What is blood doping?

Answer 4

inject “hemoglobin” to have more O2 transport capabilities

Question 5

What is the percent that oxygen can be carried by physically dissolved?

Answer 5

1.5- 2

Question 6

What is the percent that oxygen can bind to hemoglobin?

Answer 6

98-98.5

Question 7

What is oxyhemogloin?

Answer 7

this is when haemoglobin combines with oxygen

Question 8

True or False
A small percentage of oxygen is dissolved in the plasma

Answer 8

True

Question 9

When the partial pressure of oxygen is high, what is happening to oxygen?

Answer 9

oxygen will bind to hemoglobin

Question 10

When the partial pressure of oxygen is low, what is happening to oxygen?

Answer 10

Oxygen will “unbind” from hemoglobin

Question 11

At the lung levels is there a tendency for oxygen and hemoglobin to combine?

Answer 11

yes

Question 12

At the tissue levels is there a tendency for oxygen and hemoglobin to dissociate?

Answer 12

yes

Question 13

What is the average amount of oxygen we need in the blood per minute for basal function?

Answer 13

250ml O2/min

Question 14

1 single hemoglobin is composed of what?

Answer 14

1. 4 heme groups/molecule
2. 4 globin subunits/molecules
3. 4 O2 molecules

Question 15

How many O2 molecules can bind one hemoglobin molecue?

Answer 15

4, one per heme group

Question 16

where is hemoglobin found?

Answer 16

in the red blood cells

Question 17

Does Oxyhemoglobin have any pressure?

Answer 17

NAURR

Question 18

For 1 gram of hemoglobin how many ml of O2 can it bind?

Answer 18

1.34 ml/g of O2

Question 19

What is the general concentration of hemoglobin in the blood?

Answer 19

15g/100ml of blood

Question 20

What 2 factors determines O2 carrying capacity?

Answer 20

1. Total amount of Hb
2. PO2 (alveolar and arterial)

Question 21

if you have emphysema, or any obstructive lung disorder than your PO2 in the arterial blood is going to be a little bit lower, because of what?

Answer 21

because less oxygen is getting across in the first place

Question 22

What is the relationship that is being measured on an oxygen hemoglobin dissociation curve?

Answer 22

PO2 of the arterial blood and the % of Hb saturation

Question 23

At the sight of gas exchange what is the arterial PO2 of the blood? (at the lungs)

Answer 23

100 mmhg

Question 24

At the sight right after gas exchange at the tissues what is the arterial PO2 of the blood? (veinous circulation)

Answer 24

40 mmhg

Question 25

True or False The percent of oxyHb is high where the partial pressure of oxygen is high? (lungs)

Answer 25

True

Question 26

True or False The percent of oxyHb is low where the partial pressure of oxygen is low? (tissue)

Answer 26

True

Question 27

What is a scenario where oxygen does not have enough time to bind to Hb?

Answer 27

- really heavy exercise - diffusion limitation

Question 28

What is the Bohr effect?

Answer 28

when the oxygen hemoglobin dissociation curve is shifter to the right, aka favouring dissociation

Question 29

What are the causes of the Bohr effect?

Answer 29

1. Higher temperature 2. BPG 2-3

Question 30

True or False The partial pressure of oxygen is the main facter determining the percentage of Hb saturation

Answer 30

True

Question 31

On the oxygen hemoglobin dissociation curve what does the plateau/flat part represent?

Answer 31

where PO2 can be at 60 or greater for sufficient Hb situations - at the level of the lungs

Question 32

On the oxygen hemoglobin dissociation curve what does the steep part represent?

Answer 32

at the level of the tissue - where PO2 is dropping making the affinity for oxygen low

Question 33

When does the affinity of O2 to Hb drop?

Answer 33

approx 60 mmhg

Question 34

True or False Hb is responsible for 98% of O2 transport from the lungs to the tissue

Answer 34

True

Question 35

Can we have a slightly lower PO2 and be fully oxygenated from an O2- Hb saturation point of view?

Answer 35

Yes, the buffer period greater than 60

Question 36

Why would breathing too much oxygen be hurtful?

Answer 36

having chronic high levels of oxygen can lead to oxidative stress in the blood vessels

Question 37

True or False If we are already normally saturated with 98,99% saturation, breathing supplemental pure oxygen is not going to increase your oxygen saturation

Answer 37

True, because oxygen will follow concentration gradients but we cannot double the amount of Hb saturation

Question 38

As we go higher in altitude what is happening to our oxygen saturation? is it getting higher or lower?

Answer 38

Lower, the percent oxygen saturation falls

Question 39

At what altitude can we be almost fully saturated? (highest altitude to be fully saturated)

Answer 39

approx 20,000

Question 40

if we go from 22,000-25,000, what would happen to our oxygen saturation?

Answer 40

almost cut in half

Question 41

Somebody with anemia will have less of what?

Answer 41

Hb

Question 42

Will the O2 dissociation curve for individuals with anemia look the same compared to a healthy individual?

Answer 42

yes, because their Hb will be fully saturated they just happened to have less Hb

Question 43

Will the amount of O2 in the blood be the same, lower or higher for an individual with anemia compared to a healthy individual?

Answer 43

lower, because there is less Hb available

Question 44

What are 3 physiological factors that can change the O2 dissociation curve?

Answer 44

1. High arterial PCO2 2. High acidity/decrease in pH in the blood 3. Increased temperatures

Question 45

When would we see a rightward shift in the dissociation curve?

Answer 45

during exercise, all of the physiological factors would be occurring

Question 46

The Bohr effect is when we have what?

Answer 46

1. increased PCO2 2. increased acidity 3. Increased temperatures

Question 47

True or False The Bohr effect promotes the unloading of oxygen

Answer 47

True