pH and Acid-Base Balance lab

Flashcards on pH, acid-base balance, and related concepts from lecture notes.

Normal pH of blood plasma

7.38 - 7.42

Normal pH of ECF

7.35-7.42

Normal pH of ICF

Range 6.0 - 7.4, average 7.0

The Halden effect describes the difference in pH between…

Aortic blood (pH 7.4) and venous blood (pH 7.35)

Acidic

pH < 7

Neutral

pH = 7

Basic

pH > 7

Bicarbonate

HCO3-

Buffers

Substances that minimize changes in pH by binding or releasing H+ ions.

Primary buffers in extracellular fluid

Carbonic acid and proteins

Primary buffers in renal tubular filtrate

Phosphate and ammonia

Primary buffers in intracellular tissues

Proteins, bicarbonate and phosphate

Buffers of the organism - Erythrocytes

Hemoglobin, carbonic acid, phosphate

What buffers are contained in CSF?

Carbonic acid

What buffers are contained in bone?

Hydroxyapatite/calcite

ICF buffers of the organism

Proteins, hemoglobin (RBC), phosphate, bicarbonate (RBC)

ECF buffers of the organism

Bicarbonate, phosphate (urine), NH4+ (urine), proteins (blood plasma), hydroxyapatite/calcite (bones/eggshell)

What is the role of cerebrospinal fluid?

Maintain stability, remove CO2

What is the role of the kidneys?

Proton removal, bicarbonate retrieval, bicarbonate renewal, ammoniogenesis and phosphoric acid

Direct proton removal

proton pump, K-H exchanger, Na-H exchanger

Acidosis

pH below 7.35

Alkalosis

pH above 7.45

Respiratory acidosis

Caused by hypoventilation and accumulation of CO2

Metabolic acidosis

Caused by overproduction/overconsumption of acids, or removal of bases.

Respiratory alkalosis

Caused by hyperventilation and excessive ejection of CO2.

Metabolic alkalosis

Caused by overconsumption of bases or removal of protons.

How can the body compensate for acidosis/alkalosis?

Respiratory (fast) and renal (slow) compensation

Respiratory compensation for acidosis

Increase hyperventilation to remove CO2, binding of H+ in H2O

Respiratory compensation for alkalosis

Hypoventilation, accumulation of CO2, carbonic anhydrase-mediated creation of H + HCO3-, kidney elimination of bicarbonates

Renal compensation for acidosis

Excretion of protons (direct, phosphate buffer, ammoniogenesis), bicarbonate retrieval, bicarbonate renewal

Renal compensation for alkalosis

Excretion of bicarbonates

Acid excess vs base excess

Acid excess: excretion of NH4. Base excess: excretion of new HCO3

Uncompensated acidosis symptoms

Nausea, vomiting, and malaise

Uncompensated alkalosis symptoms

Nausea, numbness, muscle spasms, twitching, and malaise

Liver in acid-base balance

Synthesis of plasma proteins (buffer), metabolism of acids (gluconeogenesis, ketogenesis, citrate circle), deamination and ureagenesis

What are Rumen Acidosis and Alkalosis?

Rumen acidosis is pH