Acid-base balance

Definition

Acid-base balance refers to the mechanisms that the body uses to maintain the pH of its fluids within a narrow range, typically between 7.35 and 7.45. This balance is essential for normal cellular functions and is regulated by various systems, including the respiratory system and the kidneys, which work together to neutralize excess acids or bases in the body.

5 Must Know Facts For Your Next Test

1. The body uses bicarbonate as a key buffer to maintain acid-base balance by neutralizing excess acids.
2. Acidosis occurs when blood pH falls below 7.35, while alkalosis occurs when it rises above 7.45, leading to various physiological symptoms.
3. The kidneys play a crucial role in long-term regulation of acid-base balance by excreting or reabsorbing bicarbonate and hydrogen ions.
4. Respiratory rate can quickly change to compensate for acid-base imbalances; for instance, hyperventilation reduces carbon dioxide levels, raising pH.
5. Acid-base imbalances can result from various conditions, such as chronic obstructive pulmonary disease (COPD), renal failure, or excessive vomiting.

Review Questions

• How do the kidneys and lungs work together to maintain acid-base balance in the body?
  • The kidneys and lungs collaborate to maintain acid-base balance by regulating bicarbonate and carbon dioxide levels. The kidneys can adjust the excretion or reabsorption of bicarbonate and hydrogen ions over hours to days, providing long-term regulation. In contrast, the lungs can change carbon dioxide levels through respiration in minutes, allowing for quick adjustments to shifts in pH, ensuring the body stays within its optimal range.
• What are the clinical implications of acidosis and alkalosis on patient care?
  • Acidosis and alkalosis can have significant clinical implications for patient care, affecting various organ systems. Acidosis may lead to confusion, lethargy, and cardiovascular problems due to decreased neuronal excitability. Alkalosis may result in muscle twitching, cramping, or spasms due to increased neuronal excitability. Recognizing these conditions early allows healthcare providers to implement timely interventions to restore proper acid-base balance.
• Evaluate the impact of chronic diseases on acid-base balance and how they can lead to imbalances.
  • Chronic diseases like diabetes mellitus and COPD can significantly impact acid-base balance by disrupting normal metabolic and respiratory functions. In diabetic ketoacidosis, increased production of ketone bodies leads to metabolic acidosis. In COPD, impaired gas exchange causes retention of carbon dioxide, leading to respiratory acidosis. Understanding how these conditions alter acid-base status is crucial for effective management and treatment strategies in patients with chronic health issues.

Related terms

pH: A scale used to specify the acidity or basicity of an aqueous solution, with lower values indicating higher acidity and higher values indicating greater alkalinity.

Buffer system: A solution that resists changes in pH upon the addition of small amounts of acid or base, primarily composed of weak acids and their conjugate bases.

Respiratory compensation: The process by which the respiratory system adjusts the rate of carbon dioxide exhalation to help regulate blood pH during acid-base imbalances.