Respiratory: Gas Transport

Question 1

What is Henry’s Law?

Answer 1

The amount of a given gas dissolved in a liquid is propotional to the partial pressure of the gas in equilibrium with the liquid
So- increase the partial pressure of the gas, increased gas will dissolve in the liquid

Question 2

How is oxygen transported in the blood

Answer 2

bound to haemoglobin

dissolved

Question 3

How many haem groups does haemoglobin contain

Answer 3

four

Question 4

Describe the co operivity displayed by haemoglobin

Answer 4

When oxygen binds to one haem group it increases the affinity for the other haem groups for oxygen

Question 5

What is the primary factor in determining the percentage od saturation of haemoglobin

Answer 5

PO2

Question 6

What is the significance of the sigmoid shape of the O2-Hb dissociation curve

Answer 6

In pulmonary capillaires- a change in PO2 does not really affect the Hb saturation
In systemic capillaries- a small change in PO2 will result in oxygen dissociating from Hb

Question 7

What is the oxygen delivery index

Answer 7

Oxygen content of arterial blood times the cardiac index

Question 8

What determines the oxygen content of arterial blood

Answer 8

Hb conc

Saturation of Hb with oxygen

Question 9

What can impair oxygen delivery to the tissues?

Answer 9

Respiratory disease
Heart failure
Anaemia

Question 10

What does the Bohr effect mean

Answer 10

That there is an increased release of oxygen in the following conditions at tissues:
Increase carbon dioxide
Decreased pH
Increased temp
Increased 2,3 biphosphoglycerate

Question 11

Where is myoglobin present

Answer 11

skeletal and cardiac muscle

Question 12

How many haem groups are in a myoglobin molecule

Answer 12

one

Question 13

What is the dissociation curve shape in myoglobin

Answer 13

hyperbolic

Question 14

When does myoglobin release o2

Answer 14

in very low oxygen conc

Question 15

Why is this useful

Answer 15

Provides oxygen in anaerobic conditions

Question 16

What does the presence of myoglobin in the blood indicate

Answer 16

muscle damage

Question 17

How is carbondioxide transported in the blood

Answer 17

as a solution
as bicarbonate (most)
as carboamino compounds

Question 18

Where does bocarbonate formation occur and what enxyme catalyses it

Answer 18

red blood cells

carbonic anhydrase

Question 19

When are carboamino compounds formed?

Answer 19

By combination of CO2 with terminal amine groups in blood proteins such as globin of haemoglobin

Question 20

What is the haldane effect

Answer 20

removing oxygen from Hb increases its affinity for CO2 and H plus

Question 21

How do the bohr and haldane effect work together

Answer 21

this ensure release of O2 at tissues is coupled with uptake of CO2 to be removed