Acid-Base Homeostasis

Definition

Acid-base homeostasis refers to the body's tight regulation of the pH levels in the blood and other bodily fluids. It involves the delicate balance between acids and bases to maintain a slightly alkaline pH, which is crucial for proper physiological functioning.

5 Must Know Facts For Your Next Test

1. The normal pH range for arterial blood is between 7.35 and 7.45, which is slightly alkaline.
2. The lungs and kidneys work together to maintain acid-base homeostasis by regulating the levels of carbon dioxide and bicarbonate in the body.
3. Buffers, such as the bicarbonate-carbonic acid system, help stabilize pH by neutralizing excess acids or bases.
4. Disruptions in acid-base balance can lead to various disorders, including metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis.
5. Proper acid-base homeostasis is essential for the optimal functioning of enzymes, cellular processes, and the transportation of oxygen and carbon dioxide in the blood.

Review Questions

• Explain the role of the lungs and kidneys in maintaining acid-base homeostasis.
  • The lungs and kidneys work together to regulate the body's pH levels and maintain acid-base homeostasis. The lungs control the levels of carbon dioxide (CO2) in the blood by adjusting the rate and depth of breathing. Excess CO2 is exhaled, which helps lower the acidity of the blood. The kidneys, on the other hand, regulate the levels of bicarbonate (HCO3-) in the blood. They can either retain or excrete bicarbonate to help neutralize excess acids or bases and maintain the appropriate pH balance.
• Describe how buffers help stabilize pH in the body.
  • Buffers play a crucial role in maintaining acid-base homeostasis by helping to stabilize pH levels. The bicarbonate-carbonic acid system is a primary buffer in the body, where bicarbonate (HCO3-) and carbonic acid (H2CO3) work together to neutralize excess acids or bases. When an acid is introduced, the bicarbonate can accept a hydrogen ion (H+) to form carbonic acid, which then dissociates into water (H2O) and carbon dioxide (CO2). Conversely, when a base is introduced, the carbonic acid can donate a hydrogen ion to neutralize the base. This buffering action helps keep the pH within the narrow, slightly alkaline range required for proper physiological functioning.
• Analyze the potential consequences of a disruption in acid-base homeostasis.
  • Disruptions in acid-base homeostasis can have severe consequences for the body's overall health and functioning. Metabolic acidosis, characterized by an excessive buildup of acids in the blood, can lead to symptoms like fatigue, nausea, and confusion, and if left untreated, can progress to life-threatening complications. Metabolic alkalosis, on the other hand, involves an excess of bases in the blood, which can cause muscle spasms, confusion, and cardiac arrhythmias. Respiratory acidosis and alkalosis, caused by imbalances in carbon dioxide levels, can also have detrimental effects on the body, including headaches, drowsiness, and irregular breathing. Maintaining proper acid-base homeostasis is crucial for the optimal functioning of enzymes, cellular processes, and the transportation of oxygen and carbon dioxide in the blood, and disruptions can have far-reaching impacts on overall health and well-being.

Related terms

pH:

A measure of the acidity or basicity of a solution, with a range from 0 (highly acidic) to 14 (highly basic), and a neutral pH of 7.

Buffers: Substances that help resist changes in pH by neutralizing excess acids or bases, maintaining a stable pH environment.

Respiratory Regulation: The control of blood pH through the regulation of carbon dioxide levels by the respiratory system.