Acid-Base Balance

Acid- releases

Base- combines

7

1-6 (1 very acidic)

8-14 (14 most basic)

Alkaline

Between 7.35 and 7.45

1. Aerobic respiration of glucose, fatty acids, and amino acids

2. Anaerobic respiration of glucose

3. Formation of ketones

4. Breakdown of nucleic acids and proteins

Mito. produces CO2; CO2 combines with water to produce carbonic acid which is converted to hydrogen ions and bicarbonate

Chemical and Physiological

To stabilize the pH of a solution

Take up H+ when body fluids are becoming acidic

Give up H+ when body fluids are becoming basic (alkaline)

1. Bicarbonate buffer system

2. Phosphate buffer system

3. Protein buffer system

Acidic- Hydrogen ions combine with bicarbonate thus reducing hydrogen ions in a solution

Basic- Carbonic acid releases H+ and bicarbonate thus increasing H+ in solution

Respiratory and Renal (kidneys)

Increase:

Increase in rate of breathing

Decrease:

Decrease in rate of breathing

Buffers pH by increasing or decreasing excretion and reabsorption of H+

Acidosis

Alkalosis

When chemical and physiological buffers return pH back to normal

Respiratory and Renal

Change in rate and depth of breathing

Change in H+ excretion and reabsorption & change in HCO3- excretion and reabsorption

Direction of the pH change and underlying problem

pH below 7.35, results from addition of acids or loss of HCO3-, causes abnormal rise in H+ in body fluids

pH value above 7.45, results from loss of acids or accumulation of HCO3-, cause abnormal decrease in H+

Respiratory disturbance and metabolic disturbance

imbalance due to change in respiratory function

imbalance is due to any other change besides respiratory function

Respiratory and metabolic acidosis

Increase in CO2

1. Brain injury resulting in a decrease in rate and depth of breathing

2. Obstruction of air ways which interferes with air movement

3. Diseases such as pneumonia or those that reduce surface area of the respiratory membrane; decrease gas exchange

Resp. comp. is usually not available since the cause is with the respiratory system

kidneys will excrete more H+ & syn. and reabsorb more HCO

Due to increase in non-respiratory acids (H+) or loss of bases (HCO3)

1. Kidney disease that causes decrease excretion of H+

2. Severe diarrhea

3. Ketoacidosis due to diabetes mellitus

Increase in depth and rate of breathing, causes decrease in CO2, and causes decrease in H+

kidneys will excrete more H+ and increase reabsorption of HCO3, cause decrease in H+, and renal compensation will not be available if the cause is the kidneys

Loss of acids or accumulation of HCO3

1. Respiratory alkalosis

2. Metabolic alkalosis

Decrease in CO2

Severe anxiety and aspirin overdose

Resp. comp. may not be available, decrease in rate and depth of breathing, causes an increase in CO2, and causes an increase in H+

Kidneys decrease excretion of H+ and decreased reabsorption with increased excretion of HCO3

Loss of non-respiratory acids or gain of HCO3

Vomiting, consuming large amounts of antacids, and increased loss of acids by kidneys due to overuse of diuretics

Decrease in rate and depth of breathing, causes increase in CO2, and causes increase in H+

Kidneys decrease excretion of H+ & increased excretion with decreased reabsorption of HCO3

1. Chemical- can buffer strong acids and strong bases almost immediately

2. Respiratory- requires several minutes to begin

3. 1 to 3 days to regulate changes in H+