Buffer systems

What is the normal blood pH range?

7.35–7.45

What are the three systems that control blood pH?

Chemical buffers, respiratory regulation, and renal regulation.

What is the role of buffers in acid-base balance?

Buffers resist sudden pH changes by binding or releasing H⁺.

What is the most important buffer system in extracellular fluid?

Bicarbonate buffer system.

Write the equation for the bicarbonate buffer system.

$$\text{CO}_2 + \text{H}_2\text{O} \rightleftharpoons \text{H}_2\text{CO}_3 \rightleftharpoons \text{H}^+ + \text{HCO}_3^-$$

What happens when blood pH drops?

H⁺ binds to bicarbonate, reducing acidity.

What is the primary buffer system in intracellular fluid?

Phosphate buffer system.

What is the major buffer found in red blood cells?

Hemoglobin.

How do the lungs regulate pH?

By controlling CO₂ levels.

What happens when blood pH decreases?

Respiratory rate increases, more CO₂ is exhaled.

What is the effect of decreased respiratory rate on blood pH?

CO₂ accumulates, leading to lower pH.

What is the role of kidneys in acid-base balance?

They control pH by secreting H⁺, reabsorbing HCO₃⁻, and generating new bicarbonate.

How long does renal regulation take to adjust pH?

Hours to days.

Define acidosis in terms of pH.

Acidosis occurs when pH is less than 7.35.

What causes respiratory acidosis?

CO₂ retention due to hypoventilation or chronic obstructive pulmonary disease (COPD).

What causes metabolic acidosis?

Loss of bicarbonate or an excess of acid, such as in diarrhea or diabetic ketoacidosis (DKA).

Define alkalosis in terms of pH.

Alkalosis occurs when pH is greater than 7.45.

What causes respiratory alkalosis?

Loss of CO₂ due to hyperventilation.

What is a common cause of metabolic alkalosis?

Excess bicarbonate or loss of acid, such as from vomiting.

What are compensation patterns in acid-base balance?

Respiratory problems lead to renal compensation; metabolic problems lead to respiratory compensation.

What is the primary function of buffers?

To resist changes in pH.

How is pH ultimately determined in the body?

By the ratio of HCO₃⁻ (metabolic) to CO₂ (respiratory).

What does the Henderson-Hasselbalch equation illustrate?

pH depends on the ratio of bicarbonate (HCO₃⁻) to carbon dioxide (CO₂).

What happens to pH when the ratio of HCO₃⁻ to CO₂ increases?

The pH increases.

What is the compensation response for metabolic acidosis?

Hyperventilation (Kussmaul breathing).

What effect does anxiety have on respiratory pH balance?

It leads to respiratory alkalosis.

What are the clinical signs of Chronic Obstructive Pulmonary Disease (COPD)?

Chronic respiratory acidosis with renal compensation.

What is the primary compensatory mechanism in respiratory alkalosis?

Kidneys excrete HCO₃⁻.

What are two important functions of the kidneys related to acid-base balance?

Secreting H⁺ and reabsorbing HCO₃⁻.

Define fully compensated state in acid-base balance.

pH is normal while CO₂ and HCO₃⁻ levels are both abnormal.

How quickly does respiratory compensation occur?

Begins within 1–3 minutes.

What is the strongest buffer system in urine and intracellular fluid?

Phosphate buffer system.

What clinical condition results from metabolic alkalosis due to vomiting?

A decrease in circulating levels of acid.

Which buffer system works best when both lung and kidney functions are intact?

Bicarbonate buffer system.

What is the primary acid in the blood that affects pH?

Carbonic acid (H₂CO₃).

How does renal compensation differ from respiratory compensation?

Renal compensation is slower but more precise and long-lasting.

What is the Bohr effect?

Hemoglobin binds H⁺ when it releases O₂.

What happens to blood pH during DKA?

Metabolic acidosis occurs.

How does the body react to metabolic alkalosis?

Hypoventilation occurs to retain CO₂.

What causes lactic acidosis?

Increased production of lactic acid, often due to exercise or condition such as sepsis.

What is the main consequence of severe respiratory issues on acid-base balance?

Inability to fully correct severe metabolic imbalances.

What happens in the body during a panic attack?

Respiratory alkalosis due to hyperventilation.