Gaseous diffusion and transport online lesson

Question 1

What can cause a Bohr shift to a lower affinity?

Answer 1

Increase in temp, decrease in pH, increase in CO2, increase in 2,3-DPG

Question 2

What can causes a Bohr shift to a higher affinity?

Answer 2

Decrease in temp, increase in pH, decrease in CO2, decrease in 2,3-DPG

Question 3

What colour is carboxyhaemoglobin?

Answer 3

Deep cherry red colour

Question 4

What is the normal protein chain composition of hb?

Answer 4

2x alpha

2x beta

Question 5

What is the protein chain composition of foetal hb?

Answer 5

2x alpha

2x gamma

Question 6

What is cyanosis?

Answer 6

Low O2 content to the point where you turn blue. There are two types; peripheral and central. Hypoxic tissues go blue/grey

Question 7

Where is affected by central cyanosis

Answer 7

Lips, tongue, earlobes, conjuctiva

Question 8

What can cause central cyanosis

Answer 8

COPD, r-l heart shunt

Question 9

What is the haldane effect?

Answer 9

For a given pCO2, the conc of CO2 will be greater in venous than arterial blood

Question 10

What is the rate of release of CO2 into the blood?

Answer 10

4ml of CO2 per 100ml of blood passing

Question 11

How do you calculate minute ventilation?

Answer 11

Freq of breaths x tidal vol

Question 12

How do you calculate dead space ventilation?

Answer 12

Freq x dead space vol

Question 13

How do you calculate alveolar ventilation?

Answer 13

Minute ventilation - dead space ventilation?

Question 14

What is hyperventilation?

Answer 14

Lowered pCO2 in proportion to metabolism?

Question 15

What is hypoventilation?

Answer 15

Increased pCO2 in proportion to metabolism

Question 16

Why can hyperventilation lead to respiratory alkalosis?

Answer 16

Decreases pCO2, reduces [H+]

Question 17

Why can hypoventilation lead to respiratory acidosis?

Answer 17

increases pCO2, increases [H+]

Question 18

What are the symptoms of cerebral hypoxia?

Answer 18

Dizziness, visual disturbances, spasms

Question 19

What is a normal value for alveolar PO2

Answer 19

13.3 kPa

Question 20

What is a normal value for arterial pO2

Answer 20

12.5 kPa

Question 21

What is a normal value for arterial O2 content

Answer 21

200ml/litre

Question 22

What does mixed venous blood mean?

Answer 22

Venous blood which has had metabolites already taken out by cells.

Question 23

What is a normal mixed venous blood PO2

Answer 23

5.3kPa

Question 24

What is a normal mixed venous blood O2 content?

Answer 24

150ml/litre

Question 25

What is a normal mixed venous Hb saturation?

Answer 25

around 75%