Lecture 15 - Oxygen Transport - midterm 2

Question 1

1 litre of arterial blood (at sea level) contains how many ml of dissolved o2

Answer 1

3ml

Question 2

The heart pumps _____ of blood/min

Answer 2

5 L

Question 3

A total of ________ of dissolved O2 is carried in the blood/min

Answer 3

15 ml

Question 4

At rest we need around __________ for basal function

Answer 4

250ml O2/min

Question 5

The 15ml of dissolved O2 per min is not enough to live
We need a way to make up the extra 235 ml/min of O2 (hemoglobin)

Answer 5

To make up for the additional 235 ml/min of oxygen needed, the body relies on the oxygen-carrying capacity of hemoglobin.

Therefore, the additional 235 ml/min of oxygen needed can be supplied by an increase in the amount of hemoglobin circulating in the body or an increase in the amount of oxygen bound to hemoglobin.

Question 6

1 litre of arterial blood (at sea level) contains how many ml of dissolved CO2

Answer 6

30 ml of dissolved CO2 (10x more than oxygen)
This is due to the solubility coefficient (k); CO2 is far more soluble than O2

Question 7

how many heme groups/molecule are there

Answer 7

4 heme groups/molecule

Question 8

every heme group can bind ____ molecules of O2

Answer 8

4

Question 9

how any O2 molecules per hb

Answer 9

4 O2 molecules/Hb

Question 10

what give RBC their red colour

Answer 10

Hb

Question 11

When O2 is bound to Hb it has no pressure. true or false

Answer 11

true

Question 12

Hb is around __________of blood (g/ml)

Answer 12

15g/100ml

Question 13

Heart pumps around ________ blood/min

Answer 13

5000 ml/min

Question 14

In the pulmonary capillaries why do we want to keep the amount of dissolved O2 as low as possible in the plasma and RBC

Answer 14

gives more time for oxygen to move from the alveoli to the RBC} better diffusion

Question 15

what is The function of Hb in the RBC

Answer 15

to keep the dissolved O2 content in the RBC and plasma as low as possible for as long as possible

Question 16

HBO2 has no pressure, only the O2 dissolved has pressure. true or false

Answer 16

true

Question 17

In the tissues (O2 going from blood to cells), we want to keep the dissolved O2 in the plasma and RBC as high as possible for as long as possible. why?

Answer 17

allows diffusion to occur

Question 18

The partial pressure of O2 in the cells and interstitial fluid is _______, and _____ in the plasma and the RBC

Answer 18

low
high

Question 19

what is the purpose of hb in the blood

Answer 19

By putting Hb in the blood, you get a pressure gradient (the pressure in the alveoli becomes higher than the pressure in the blood; this leads to diffusion and movement from high to low)

Hb allows the partial pressure of O2 in the blood to remain low compared to the alveoli, so diffusion can occur

Hb acts as a ‘sink’ to keep PO2 as low as possible and maintains a gradient for diffusion of O2

Question 20

what happens when o2 comes in

Answer 20

As O2 comes in, the Hb molecules become fully saturated and lead to an equilibrium (equal amount of O2 molecules in the alveoli and dissolved O2 molecules in the blood) (the partial pressure of O2 in the alveoli and in the blood will always eventually reach equilibrium)