Pulmonary Blood Flow and Gas Exchange and Transport 2 & 3 Flashcards Preview

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Flashcards in Pulmonary Blood Flow and Gas Exchange and Transport 2 & 3 Deck (83)
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1

What does the blood transport between the lungs and tissues?

Oxygen

2

What does blood transport between the tissues and the lungs?

Carbon dioxide

3

What is the waste product of using oxygen to produce energy?

Carbon dioxide

4

How much oxygen dissolves per litre of blood plasma?

3ml

5

How is the blood carrying capacity of oxygen increased?

Presence of haemoglobin

6

What does haemoglobin increase the oxygen carrying capacity of blood to?

200ml/L

7

How is CO2 transported in the plasma?

In various forms

8

What is arterial partial pressure of oxygen (PaO2) not the same as?

O2 concentration/content

9

What does PaO2 refer to?

O2 in solution 

10

What is PaO2 determined by?

O2 solubility and the partial pressure of O2, in the gaseous phase that is driving O2 into solution

11

How do values of partial pressure of gases in solution compare to the partial pressure in gaseous phase that is driving the gas into solution?

They are equal

12

What is O2 solubility in water?

Low

0.03ml/L/mm/Hg

13

If 3ml of oxygen is present per litre of plasma, what is the partial pressure that is driving O2 into the loquid phase in plasma?

100mmHg

This is because solubility of water is 0.03ml/L/mmHg (3/0.03 = 100)

14

What is the partial pressure of oxygen also known as?

Oxygen tension

15

How does PO2 in the liquid phase compare to that in the gaseous phase, and to the concentration in the liquid phase?

PO2 is the same in the liquid phase as the gas phase

PO2 in the liquid phase is different from the concentration as that varies depending on what phase the gas is in

16

How many molecules are there of oxygen in 1L of gas compared to 1L of liquid?

30x more oxygen molecules

17

How do you work out the O2 delivery to tissues?

Arterial O2 content x Cardiac output

 

3ml/L x 5L/min = 15ml/min

18

What percentage of arterial O2 is extracted by peripheral tissues at rest?

25%

19

What does reduced PO2 result in for oxygen carrying capacity of red blood cells and plasma?

Decreases blood carrying capacity

20

What is the abbreviation of haemoglobin?

Hb

21

What percentage of oxygen in systemic arterial circulation is bound to haemoglobin?

More than 98%

22

How much oxygen does 1L of systemic arterial blood contain?

200ml

23

How does haemoglobin bind to oxygen?

Cooperatively binds to 4 molecules of oxygen

24

How much oxygen binds to each gram of haemoglobin?

1.34ml

25

What form is most haemoglobin in red blood cells in?

HbA (92%)

26

What does a haemoglobin molecule contain?

a chain

b chain

Haem group

27

What are some forms of haemoglobin other than HbA?

HbA2 (δ chains replace β)

HbF (γ chains replace β)

Glycosylated Hb (HbA1a, HbA1b, HbA1c)

28

What is the major determinant for the degree to which haemoglobin is saturated with oxygen?

Partial pressure of oxygen in arterial blood

29

Why does the partial pressure of oxygen not change as haemoglobin binds to it?

It effectively hides it from the plasma, maintaining the partial pressure gradient that continues to suck O2 out of alveoli until Hb becomes saturated

30

What formula represents Hb binding to oxygen?

Hb + O2 ⇔ HbO2