Acid-Base Balance

7.35-7.45

What is the normal pH of the body?

The acidity or alkalinity of a solution

What is does pH measure?

Larger number of H ions (acidosis) or smaller number of H ions (alkalosis)

What what does increased pH (>7.35) or decreased pH (<7.45) mean?

Compound that allows hydrogen ions to break free (decreased pH)

What is an acid?

Compound that binds with hydrogen ions (increased pH)

What is a base?

Through chemical buffer systems which keeps pH relatively constant

How does the body regulate pH?

1. CARBONIC ACID (BICARBONATE BUFFER SYSTEM)

2. Phosphate buffer system

3. Protein buffer system

What are the chemical buffer systems in the body?

• Carbonic acid (acid) = H2CO3 (CO2 and H2O)

• Bicarbonate (base) = HCO3

What are the acids and bases involved in carbonic acid (bicarbonic buffer system)?

1. RESPIRATORY CONTROL (CO2 CHANGES)

2. RENAL REGULATION (METABOLIC HCO3 CHANGES)

What two systems are involved in the carbonic acid (bicarbonate buffer system)?

• Respiratory: seconds to minutes

• Renal: several hours to days

How long do changes take in the respiratory vs. renal system for carbonic acid (bicarbonate buffer system) regulation?

• Acidic: increase resp. rate and depth

• Alkaline: decrease resp rate and depth

How does the body regulate acid and alkaline pH in the respiratory system?

• Acidic: H+ excreted in urine

• Alkaline: HCO3 excreted in urine

How does the body regulate acid and alkaline pH in the renal system?

• Respiratory acidosis/alkalosis

  • ROOT CAUSE in ventilation and/or alveoli gas exchange

• Metabolic acidosis/alkalosis

  • ROOT CAUSE in metabolism (not respiratory)

What are the types of acid-base disturbances?

Abnormal increase in hydrogen ion concentration

• Accumulation of EXCESS acid

OR

• LOSS of bicarbonate

What is acidosis?