Which organ system alters kidney functions?
a. Excretory
b. Respiratory
c. Immune
d. None of the above
The correct answer and explanation is :
Correct Answer: b. Respiratory
Explanation:
The respiratory system plays a significant role in altering kidney function through its influence on the body’s acid-base balance. The kidneys and lungs work closely together to maintain a stable internal environment (homeostasis), particularly in regulating blood pH levels.
Here’s how the interaction works:
The lungs help regulate the amount of carbon dioxide (CO₂) in the blood. CO₂ is a byproduct of cellular metabolism and dissolves in blood to form carbonic acid. The more CO₂ in the blood, the more acidic it becomes. The respiratory system can rapidly remove excess CO₂ through exhalation, helping to reduce blood acidity.
On the other hand, the kidneys help regulate pH more slowly by excreting hydrogen ions (H⁺) and reabsorbing bicarbonate (HCO₃⁻), a base that neutralizes acid in the body. When the respiratory system is impaired (e.g., in chronic obstructive pulmonary disease or hypoventilation), CO₂ can accumulate, leading to respiratory acidosis—a condition where the blood becomes too acidic. In response, the kidneys compensate by increasing the excretion of hydrogen ions and conserving bicarbonate.
Conversely, in respiratory alkalosis—caused by hyperventilation and excessive loss of CO₂—the blood becomes too basic (alkaline). The kidneys then reduce bicarbonate reabsorption and retain hydrogen ions to balance the pH.
This respiratory-renal partnership is critical in various physiological and pathological conditions. For instance, patients with lung disorders often experience changes in kidney function due to altered pH levels, which the kidneys must correct.
In summary, while the kidneys belong to the excretory system, it is the respiratory system that directly influences their function by affecting acid-base balance, making option b. Respiratory the correct choice.