Question

1. A professional cyclist has been training for months at HIGH ELEVATION in preparation for a race at sea level. He enters the race, wins, and after being randomly drug tested by race officials is accused of blood doping.

What did race officials likely find?

2. Why does the blood COLLOID OSMOTIC PRESSURE remain unchanged across the length of a capillary bed? It is roughly 25 mm Hg on the arterial end and 25 mm Hg on the venous end.

Answer 1

1)Blood doping is a wrong practice of boosting the number of red blood cells in the blood to enhance athletic performance. An increase in RBC would increase the blood's oxygen carrying capacity and more oxygen will be available to skeletal muscles and other organs, thereby increasing the athlete's endurance.

Since the cyclist was training at high elevation for several months, the body adapts to this less oxygen by increasing the red blood cell production and therefore the oxygen carrying capacity. This process is called ACCLIMATIZATION.

2) Blood colloidal osmotic pressure is the pressure exerted by the proteins present in blood plasma. Since these proteins cannot cross the semi permeable membrane of the capillary endothelial cells,their concentration remains same across the length of capillary bed. Thus,the blood colloidal osmotic pressure remains roughly 25 mmHg on the arterial as well as venous end.