Acid Base Balance

Flashcards for vocabulary related to acid base balance.

Acid-Base Balance

The precise regulation of free hydrogen-ion concentration in the body fluids.

Acids

Hydrogen-containing substances that dissociate in solution to liberate free H+ and anions.

Strong Acid

An acid with a greater tendency to dissociate in solution, releasing more free H+ and anions.

Weak Acid

An acid with less tendency to dissociate in solution, releasing fewer free H+ and anions.

Base

A substance that can combine with a free H+ and thus remove it from solution.

Strong Base

A base that can bind H+ more readily than a weak base.

pH

Expresses [H+] conveniently using the logarithm of the reciprocal of the hydrogen ion concentration.

Acidosis

A condition where blood pH falls below 7.35.

Alkalosis

A condition where blood pH rises above 7.45.

H+ Balance

Maintain a constant [H+] in the body fluids by balancing input and output of hydrogen ions.

Carbonic Acid Formation

H2CO3 formation from metabolically produced CO2.

Acids from Nutrient Breakdown

Sulfuric acid and phosphoric acid produced during the breakdown of dietary proteins containing sulfur and phosphorus.

Acids from Intermediary Metabolism

Acids like lactic acid produced by muscles during heavy exercise.

Chemical Buffer System

A mixture in a solution of two chemical compounds that minimize pH changes.

Four Buffer Systems

H2CO3: HCO3- buffer system, protein buffer system, hemoglobin buffer system, and phosphate buffer system.

H2CO3: HCO3 - buffer system

The most important buffer system in the ECF for buffering pH changes brought about by causes other than fluctuations in CO2-generated H2CO3.

Protein buffer system

The most important in buffering changes in [H+] in the ICF, because of the abundance of the intracellular proteins.

Hemoglobin buffer system

Buffers the H+ generated from metabolically produced CO2 in transit between the tissues and lungs.

Phosphate buffer system

Acid phosphate salt that donates a free H+ when [H+] falls and a basic phosphate salt that accepts a free H+ when [H+] rises.

Respiratory Mechanism of pH Control

Alters pulmonary ventilation and consequently alters excretion of H+-generating CO2.

Renal Mechanism of pH Control

Adjusts H+ excretion, HCO3- excretion and Ammonia (NH3) secretion.

Type A Intercalated Cells

H+ -secreting, HCO3 - - reabsorbing, K + - reabsorbing cells, active during acidosis.

Type B Intercalated Cells

HCO3 - -secreting, H+ - reabsorbing, K+ - secreting cells, active during alkalosis.

Regulation of Plasma

The kidneys regulate plasma [HCO3 -] by variable reabsorption of filtered HCO3 -, variable addition of new HCO3 - to the plasma and variable reabsorption of HCO3 -.

Possible causes of respiratory acidosis

Lung disease, depression of the respiratory center by drugs or disease, nerve or muscle disorders that reduce respiratory muscle ability, or (transiently) even the simple act of holding one’s breath.

Possible causes of respiratory alkalosis

Fever, anxiety, and aspirin poisoning. Respiratory alkalosis also occurs as a result of physiological mechanisms at high altitude.

Metabolic acidosis most common causes

Severe diarrhea, diabetes mellitus, strenuous exercise and uremic acidosis.

Causes of metabolic alkalosis

Vomiting and Ingestion of alkaline drugs