Haemoglobin and Gas transport

Question 1

How much oxygen dissolved per litre of plasma

Answer 1

3ml

Question 2

Haemoglobin is RBCs increases oxygen carrying capacity to

Answer 2

200ml/L

Question 3

Bulk of CO2 is transported in solution in

Answer 3

plasma

Question 4

Arterial oxygen content is 3ml/L and cardiac output is 5 litres therefore oxygen delivery to tissues is…

Answer 4

15ml/min

Question 5

Oxygen demand of resting tissues

Answer 5

250ml/min

Question 6

Only ……% of arterial oxygen is extracted by peripheral tissues at rest

Answer 6

25

Question 7

each litre of systemic arterial blood contains ~……ml of oxygen

Answer 7

200

Question 8

more than …..% of oxygen is bound to haemoglobin (the rest is dissolved in plasma)

Answer 8

98

Question 9

Haemoglobin cooperatively binds

Answer 9

4 molecules of oxygen

Question 10

how many ml of oxygen bind to each gram of haemoglobin?

Answer 10

1.34 ml

Question 11

92% of haemoglobin in RBCs is in the form

Answer 11

HbA

Question 12

8% (rest of) haemoglobin in RBCs is made up of

Answer 12

HbA2, HbF and glycosylated Hb

Question 13

Major determinant of the degree of which haemoglobin is saturated with oxygen is the

Answer 13

partial pressure of oxygen in arterial blood

Question 14

What is the partial pressure of a gas?

Answer 14

The hypothetical pressure of the gas if it alone occupied the entire volume of the original mixture at the same temperature

Question 15

Haemoglobin is almost 100% saturated at the normal systemic arterial PO2 which is…

Answer 15

100mmHg

Question 16

At normal venous PO2 - there is still….. %reserve capacity of saturated haemoglobin

Answer 16

75%

Question 17

HbF

Answer 17

Foetal Haemoglobin

Question 18

Anaemia

Answer 18

Any condition where the oxygen capacity of the blood is compromised

(eg iron deficiency, haemorrhage, Vitamin B12 deficiency)

Question 19

Oxygen content of plasma is

Answer 19

3mL O2/L blood

Question 20

Oxygen content of RBC

Answer 20

197ml O2/L blood

Question 21

In anaemia, PaO2 is normal despite total blood oxygen content being

Answer 21

low

Question 22

Affinity of haemoglobin for oxygen changes in response to certain

Answer 22

chemical factors

Question 23

Affinity of haemoglobin for oxygen is decreased by a

Answer 23

decrease in pH

increase in PCO2

Increase in temperature

binding of 2,3 disphosphoglycerate

Question 24

2,3-DPG is synthesised by …… and increases in situations where there is …….

Answer 24

erythrocytes

inadequate oxygen supply

Question 25

Carbon monoxide binds to Hb to form

Answer 25

carboxyhemoglobin

Question 26

carboxyhaemoblogin has an affinity ...... greater than oxygen

Answer 26

250

Question 27

Symptoms of Carbon Monoxide poisoning

Answer 27

``` nausea hypoxia anaemia headaches cherry read skin mucous membranes ``` potential brain damage and death

Question 28

Hypoxaemic hypoxia

Answer 28

most common hypoxia reduction in oxygen diffusion at lungs either due to decreases PO2atmos or tissue pathology

Question 29

Anaemic Hypoxia

Answer 29

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

Question 30

Stagnant Hypoxia

Answer 30

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

Question 31

Histotoxic Hypoxia

Answer 31

poisoning prevents cells utilising oxygen delivered to them (eg carbon monoxide/cyanide)

Question 32

Metabolic Hypoxia

Answer 32

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