Answer :
The role of the lungs in acid-base balance is primarily the regulation of carbon dioxide (CO_2).
Here's an explanation:
1. Carbon Dioxide (CO2) Regulation:
- The lungs are responsible for expelling CO2 from the body during exhalation.
- CO2, produced as a byproduct of cellular metabolism, diffuses into the blood and is transported to the lungs.
- CO2 combines with water (H2O) in the blood to form carbonic acid (H2CO3), which dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).
- The concentration of CO2 in the blood is closely related to blood pH. High CO2 levels lower pH (more acidic), while low CO2 levels raise pH (more basic).
2. Hydrogen Ions (H+):
- While the concentration of H+ does affect acid-base balance, the primary regulation of H+ occurs through the kidneys, not the lungs.
- The lungs indirectly influence H+ concentration by regulating CO2 levels.
3. Bicarbonate Ions (HCO3-):
- Similarly, HCO3- ions are involved in buffering the blood's pH.
- The kidneys primarily manage bicarbonate levels through reabsorption or secretion.
4. Water (H2O):
- While water is involved in the formation of carbonic acid (along with CO2), regulating the water balance in the body is not the primary function of the lungs with respect to acid-base balance.
- Water balance is mainly controlled by the kidneys and other organ systems.
Therefore, the correct answer is:
CO2
Here's an explanation:
1. Carbon Dioxide (CO2) Regulation:
- The lungs are responsible for expelling CO2 from the body during exhalation.
- CO2, produced as a byproduct of cellular metabolism, diffuses into the blood and is transported to the lungs.
- CO2 combines with water (H2O) in the blood to form carbonic acid (H2CO3), which dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).
- The concentration of CO2 in the blood is closely related to blood pH. High CO2 levels lower pH (more acidic), while low CO2 levels raise pH (more basic).
2. Hydrogen Ions (H+):
- While the concentration of H+ does affect acid-base balance, the primary regulation of H+ occurs through the kidneys, not the lungs.
- The lungs indirectly influence H+ concentration by regulating CO2 levels.
3. Bicarbonate Ions (HCO3-):
- Similarly, HCO3- ions are involved in buffering the blood's pH.
- The kidneys primarily manage bicarbonate levels through reabsorption or secretion.
4. Water (H2O):
- While water is involved in the formation of carbonic acid (along with CO2), regulating the water balance in the body is not the primary function of the lungs with respect to acid-base balance.
- Water balance is mainly controlled by the kidneys and other organ systems.
Therefore, the correct answer is:
CO2
Answer:
Option A, CO₂
Explanation:
The lungs inhale oxygen from the atmosphere for diffusion into the bloodstream in order to nourish the various tissues within the body. The byproduct that diffuses back into the bloodstream is carbon dioxide (CO₂), which is then eliminated via gas exchange by the lungs upon exhaling.
Carbon dioxide in the presence of water within the body becomes carbonic acid. It is because of this reaction that getting rid of it via exhalation (increases pH; blood is more basic, less acidic) or holding onto it via faster respirations (decreases pH; blood is less basic, more acidic) aids in the careful maintenance of the body's homeostatic acid-base balance.
Therefore, the lungs regulate CO₂, option A, in their role in acid-base balance.