Gas transport in the blood

Question 1

Where does blood transport oxygen to and from?

Answer 1

From the lungs to the tissues

Question 2

Where does the blood transport CO2 to and from?

Answer 2

From tissues to lungs for removal

Question 3

Name the two forms in which oxygen travels in the blood.

Answer 3

In solution in plasma
Bound to haemoglobin protein in RBC’s

Question 4

How much oxygen travels in the plasma?

Answer 4

Very little- 3ml O2 /litre of plasma

Question 5

How much O2 is there/litre of whole blood?

Answer 5

200ml

Question 6

How much of the 200ml is bound to haemoglobin?

Answer 6

197ml

Question 7

What is the bulk of CO2 transported in?

Answer 7

In plasma (77%)

Question 8

How is the other 23% of CO2 transported?

Answer 8

Haemoglobin

Question 9

What is the partial pressure of oxygen in the alveoli the same as?

Answer 9

The partial pressure of the plasma, at the point where equilibrium has been met.

Question 10

Which is more soluble in water; oxygen or CO2?

Answer 10

CO2

Question 11

How many haem groups does a molecule of haemoglobin have?

Answer 11

4

Question 12

What does each haem group have?

Answer 12

One Fe2+ which binds to an oxygen molecule

Question 13

How many molecules of oxygen does one haemoglobin molecule bind to?

Answer 13

Four

Question 14

What is the major determinant of the degree in which haemoglobin binds/is saturated with oxygen?

Answer 14

Partial pressure of oxygen in the blood.

Question 15

What is the partial pressure of oxygen is systemic arterial blood?

Answer 15

100ml mercury

Question 16

What is the amount of oxygen carried by haemoglobin determined by?

Answer 16

The amount of oxygen in the plasma (partial pressure of O2 in the plasma).

Question 17

What is the amount of oxygen in the solution of plasma is determined by?

Answer 17

Partial pressure of O2 in the alveoli.

Question 18

What is the partial pressure of oxygen in the alveoli determined by?

Answer 18

Alveolar ventilation

Question 19

How much oxygen can we deliver to our tissues every minute?

How much of this oxygen is used?

Answer 19

1000ml

250ml

Question 20

Define anaemia xoxox

Answer 20

YAY
any condition where the oxygen carrying capacity of the blood is compromised.

Question 21

Name three ways an individual may get anaemia xoxo

Answer 21

Iron deficiency
Haemorrhage
B12 defiviency

Question 22

List the four factors which may alter the affinity of haemoglobin for oxygen.

Answer 22

pH
Temperature
PCO2 (partial pressure)
DPG

Question 23

If the body needs more oxygen, what will happen to pH, temperature and PCO2 in order for the body to get access to the 75% of oxygen it does not usually have access to?

Answer 23

Lower pH
Increase temperature
Increase PCO2.

Question 24

What happens if we increase pH and decrease temp and PCO2?

Answer 24

Haemoglobin’s affinity for oxygen increases and hangs onto it more tightly and will not give any to the peripheral tissues.

Question 25

What is DPG a by product of?

Answer 25

The metabolism of red blood cells

Question 26

Does DPG increase or decrease haemoglobin's affinity for oxygen?

Answer 26

Reduces affinity

Question 27

Give examples of situations in which DPG production is increased.

Answer 27

Lung disease Heart Disease Individuals who live at high altitudes.

Question 28

*STOP* Revision task coming up for everything learned so far :)

Answer 28

Look at Lecture 4.2-45 mins. Copy this out but add more detail to make sure you remember all important bits :)

Question 29

When does carbon monoxide form?

Answer 29

When there is incomplete combustion of carbon fuel (car exhaust fumes, lawnmower, faulty heating appliances etc.)

Question 30

What do you get when carbon monoxide joins w haemoglobin?

Answer 30

Carboxyhaemoglobin

Question 31

Why is carbon monoxide toxic?

Answer 31

Has very high affinity for haemoglobin so if there if there is any CO, it will bind tightly to haemoglobin and dissociate very slowly.

Question 32

Name some of the symptoms of someone who has CO in their body.

Answer 32

Hypoxia, anaemia, nausea, headache, cherry red skin and mucous membranes. Respiration rate unaffected due to normal arterial PCO2. Potential brain damage and death.

Question 33

What is the treatment of CO?

Answer 33

100% oxygen to increase PO2.

Question 34

How is CO2 produced?

Answer 34

By product from cellular respiration

Question 35

How much carbon dioxide stays in the plasma after diffusing across the membrane?

Answer 35

7%

Question 36

What percentage of CO2 goes into red blood cells?

Answer 36

93%

Question 37

Carbon dioxide joins with deoxyhaemoglobin to form what?

Answer 37

Carbamino compounds

Question 38

What is produced if carbon dioxide reacts with enzyme carbonic anhydrase?

Answer 38

Carbonic acid is formed

Question 39

What happens in the chloride shift?

Answer 39

Exchange bicarbonate ions for chloride ions.

Question 40

What does carbonic acid split to give us?

Answer 40

Bicarbonate and hydrogen ions.

Question 41

What does the arterial partial pressure of oxygen solely refer to?

Answer 41

Oxygen in solution in plasma

Question 42

What is the arterial partial pressure of oxygen determined by?

Answer 42

Oxygen solubility

Question 43

What is the partial pressure of oxygen?

Answer 43

O2 in the gaseous phase that is driving O2 into solution

Question 44

What phases do gases not travel in the plasma and why?

Answer 44

Do not travel in the gaseous phase as would cause bubbles in the blood and a fatal air embolism!

Question 45

Name the process by which haemoglobin cooperatively binds four molecules of oxygen.

Answer 45

Oxygenation

Question 46

What is the most abundant form of haemoglobin in RBC's?

Answer 46

Adult haemoglobin

Question 47

What % of haemoglobin in RBC does HbA make up?

Answer 47

92%

Question 48

What is the other 8% of haemoglobin composed of?

Answer 48

HbA2, HbF, glycosylated Hb

Question 49

Describe HbA2

Answer 49

Delta chains replace beta chains.

Question 50

Describe HbF

Answer 50

Foetal haemoglobin- gamma chains replace beta chains

Question 51

Which types of chain are in adult haemoglobin?

Answer 51

Alpha and Beta chains

Question 52

Why is glycosylated Hb important clinically?

Answer 52

Can be used in monitoring of diabetes and blood glucose control in diabetes.

Question 53

What is myoglobin?

Answer 53

Oxygen carrier molecule found only in cardiac and skeletal muscle.

Question 54

When might you see myoglobin in the blood?

Answer 54

If someone has extensive muscle damage

Question 55

Do myoglobin and foetal haemoglobin have a higher or lower affinity for oxygen compared to adult haemoglobin?

Answer 55

Higher affinity

Question 56

Why is foetal haemoglobin important?

Answer 56

Allows the foetus to access oxygen in maternal blood

Question 57

What is hypoxia?

Answer 57

Inadequate oxygen to tissues

Question 58

Name the five types of hypoxia.

Answer 58

1. Hypoxaemic Hypoxia 2. Anaemic Hypoxia 3. Stagnant Hypoxia 4. Histotoxic Hypoxia 5. Metabolic Hypoxia

Question 59

Describe hypoxaemic hypoxia.

Answer 59

Reduction in O2 diffusion at lungs either due to decreased PO2atmos or tissue pathology.

Question 60

Describe anaemic hypoxia

Answer 60

Reduction in O2 carrying capacity of blood due to anaemia (red blood cell loss/iron deficiency).

Question 61

Describe stagnant hypoxia

Answer 61

Heart disease results in inefficient pumping of blood to lungs/around the body

Question 62

Describe histotoxic hypoxia.

Answer 62

Poisoning prevents cells utilising oxygen delivered to them e.g. carbon monoxide/cyanide

Question 63

Describe metabolic hypoxia

Answer 63

Oxygen delivery to the tissues does not meet increased oxygen demand by cells.

Question 64

What is the most common type of hypoxia?

Answer 64

Hypoxaemic hypoxia