Final answer:
The primary route for lactic acid elimination is through blood circulation. It is neutralized and then converted into carbon dioxide and water, which are exhaled. The liver also assists in metabolizing lactic acid into energy.
Step-by-step explanation:
The principal route of elimination of lactic acid is via the bloodstream to the liver. When we exercise, our muscles produce lactic acid, which is then neutralized in the bloodstream by the bicarbonate ion, HCO3¯, resulting in the production of carbonic acid (H₂CO₃). This is swiftly broken down by an enzyme into carbon dioxide and water, which can be easily removed from the body through breathing. The liver also plays a crucial role in eliminating lactic acid as it can convert lactic acid back into pyruvic acid, which is further metabolized for energy.
Lactic acid fermentation also occurs in muscle cells and certain bacteria, such as those used in the production of yogurt. However, if lactic acid is not efficiently metabolized, as occurs with tremetol poisoning from the white snakeroot plant, symptoms such as vomiting, abdominal pain, and tremors can result and worsen with exercise.