1. Transport of O 2 in blood: 1. Some dissolved  1.5% at normal atmospheric pressure 2. Most combined with hemoglobin  98.5%

3. Fe 2+ Oxygenation is reversible

4. ml O 2 / 100 ml blood 2 1 Each gm Hb binds 1.34 ml O 2 Each 100 ml blood has 15 g Hb 1 2 Blood nearly fully oxygenated even if PO 2 < 100 mmHg Hemoglobin gives up large volume of O 2 for a small drop in PO 2 at tissues

6. Factors which influence O 2 binding to HB O 2 affinity for Hb * is decreased by:  PCO 2  pH acidosis  temperature  2,3 diphosphoglycerate *  affinity = shift of O 2 –Hb curve to right = easier unloading of O 2

7. CO 2 (mldl –1 )SO 2 (mldl –1 )

8. O 2 carrying capacity of Hb at a particular PO 2 is decreased by  PCO 2 (Bohr effect)

10. Carbon monoxide CO 1. Odourless, colourless, non-irritant, no cyanosis 2. Combines with Hb at O 2 binding site 3. CO affinity for Hb is 200 times that of O 2 for Hb, so if CO at 0.1% in air and O 2 at 21% 1/2 Hb—CO and 1/2 Hb—O 2 at CO of 0.2% ~ nearly all Hb—CO 4. Management ~ remove from source CO ~ provide Pure O 2 (  relative O 2 pressure) ~ stimulate ventilation with some CO 2

11. Oxyhemoglobin Dissociation Curves

12. In Training:  Vital Capacity  Provision of O 2  Hb  Cardiac Output  Muscle capillary density  Red blod cell 2,3-DPG  Mitochondria + oxidative enzymes  O 2 carrying capacity

13. Hypoxia:  availability of O 2 for use by cells 1.  availability O 2 2. Pulmonary problems: i)  ventilation ii) ventilation / perfusion inequalities iii)  diffusion 3. Venous  arterial shunts 4. Inadequate transport and delivery i) anemia; abnormal Hb ii) general  circulation iii) local  circulation iv) edema (  diffusion) 5. Inadequate ability to use O 2 i) poisoning cellular enzymes e.g. cyanide ii)  oxidative enzyme activity e.g. vit B 1 deficiency

14. O 2 Transport Summary Forms in which O 2 is transported in blood Hemoglobin Hb—O 2 dissociation curve Factors affecting affinity of Hb for O 2 Carbon Monoxide Effects of training Causes of hypoxia