In: Biology
You are studying how changes in blood pH might be controlled by homeostasis. In a trial, you let a mouse run on a treadmill for a fixed period of time, and then you measure its blood pH. Intriguingly, you observe the blood pH drops (more acidic) as carbon dioxide is released into the bloodstream. Which component of the homeostatic feedback system is responsible for producing the correct response if the blood pH is far enough from normal that a response is necessary?
The blood pH should always be maintained in a narrow range [7.35-7.45] for smoot functioning of the body.
Any sudden cange in the body's pH is corrected by different homeostatic mechanisms. The major role is played by the Kidneys and the Lung.
Here in this experiment, if the blood pH falls more i.e becomes more acidic after an exercise the possible explanation for that is lactic acidosis [i.e accumulation of lactic acid in the exercising muscle due to anaerobic metaboism]
The body has different mechanisms to correct that and the major ones are:
1. Increase in the Respiratory rate. Tis causes more CO2 washout from the lungs. CO2 washout always makes the pH towards the alkaline side. so this can correct our acidosis.
2. Second mechanism is the Renal regulation of pH. Kidneys increase acid excretion (intercalated cells secrete H+ into tubules) and decrease bicarbonate excretion. When intercalated cells secrete H+ into the tubule, it combines with buffers in the lumen (ammonia) and is excreted.