Transport of oxygen in mammalian body.
- Oxygen in alveoli diffuses into capillaries of lungs;
- In capillaries it enters Red Blood Cells and combines with haemoglobin to form oxyhaemoglobin / (02 + haemoglobin = oxyhaemoglobin;
- Oxyhaemoglobin is transported from lungs to capillaries through Pulmonary Vein heart and into body tissues;
- It dissociates readily, (oxhaemoglobin); in body tissues; to oxygen due to low oxygen concentratoon in the tissues;
- oxygen diffuses from Red Blood Cells to body tissues and is used for respiration; 10 mks.
Transport of Carbon dioxide in the body.
- Carbon dioxide diffuses from respiring body tissues to blood
- It enters the Red Blood Cells and some enters plasma.
- In Red Blood Cells it combines with water to form weak carbonic acid (H2O + CO2 H2CO3)
- The acid dissociates to H+ bicarbonates. (H2CO3 H+ x CO3–)
- Dissociation is accelerated by carbonic anhydrate enzyme (that loads and unload the CO2);
- The presence of low CO2 concentrtion in lungs causes CO3 low in Red Blood Cells and plasma to dissociate ; and releases CO2;