1. Transport of Respiratory Gases

2. Carbon dioxide in blood
5% dissolves in plasma
20% combines with haemoglobin Carbaminohaemoglobin!
75% combines with water forming bicarbonate ion (hydrogen carbonate)
CO2 combines with H2O making it unstable. This releases Hydrogen ions and this reacts with oxyhaemoglobin to make acid

3. Transport of Oxygen… Some oxygen is soluble in plasma (3%)
Most is carried in haemoglobin, which is found in red blood cells. (97%)

4. Each haemoglobin molecule can carry up to 4 oxygen molecules
Oxygen & haemoglobin = Oxyhaemoglobin
This reaction is reversible and depends on the partial pressures of oxygen.

6. When all the haemoglobin is combined with oxygen it is said to be fully saturated (100%)
This happens where oxygen in the surrounding tissues is high i.e. lungs.

7. At lower concentrations (i. e
At lower concentrations (i.e. in the muscle tissues), the haemoglobin gives up its oxygen (dissociates) which reduces its percentage saturation (75%)
On returning to the lungs where there is a higher concentration of oxygen it picks up more and becomes fully saturated.

8. Oxyhaemoglobin disassociation curve
% saturation of haemoglobin at different partial pressures of oxygen.

9. Exercise!
Exercise produces conditions that cause haemoglobin to release O2 more readily. Dissociate
The haemoglobin gives up almost all of its oxygen.

10. Myoglobin
This is another respiratory pigment that is only found in the muscles.
It has a higher affinity for oxygen than haemoglobin.
It picks up all of the oxygen molecules released by haemoglobin taking it into the muscle.

11. What affects the amount of oxygen released from haemoglobin at the muscle?
1) Partial pressure of oxygen CO2
2) In acidic conditions oxygen dissociates more easily with haemoglobin.
What could cause the blood to be more acidic???
3) Increase in temperature Exercise generates heat. Decreases haemoglobin's affinity for oxygen- more is released more readily .

12. Oxyhaemoglobin Dissociation Curve
Amount O2 released
Increased O2 released
Bohr shift
pO2 in muscles
pO2 in lungs

13. Typical question
Describe how oxygen is transported to the working muscles and the effect that strenuous exercise will have on its delivery. Explain why strenuous exercise has this effect. (4 marks)

14. Answer Simplistic circulation – heart – arteries – muscles;
Oxygen as oxyhaemoglobin;
Exercise increases temperature;
More CO2 in blood/increased acidity;
Both increase release of oxygen from haemoglobin at muscles;
Bohr shift; (4 marks)

15. Typical question
Explain the causes of the Bohr shift and how it increases oxygen delivery too the working muscles
(4 marks)

17. Typical question
Where is myoglobin found and what is its role in the body? (2 marks)

18. Carry/ transport oxygen to mitochondria for respiration
Found in the muscle cell

19. Extraction of oxygen Lots of delivered to muscles
Need for muscle to remove
Difference between content of artery approaching muscle and vein leaving muscle - concept of
During exercise
oxygen-rich blood
oxygen
oxygen
a-VO2 difference
a-VO2 diff increases

20. a-vO2 diff. Artery carrying O2 to muscle
Vein carrying O2 away from muscle
Difference in oxygen concentrations between artery and vein = a-vO2 diff.

21. a-vO2 diff. Artery carrying O2 to lungs
Vein carrying O2 away from lungs
A-vO2 diff. at lungs

22. Oxygen into muscles Oxygen combines with pigment – An Used in
myoglobin
oxygen store
aerobic processes to make energy

23. Typical question
During a game, a player’s arterio-venous difference (a-vO2 diff) will increase. What is the significance of this increase in a-vO2 diff to the player? (3 marks)

24. Answer Difference between oxygen content of arterial and venous blood;
During game - more oxygen is needed/used/ extracted by the muscles/lungs;
Used/needed for energy/ATP production/aerobic/ endurance/stamina exercise;
Leads to improved performance;