8. Fluids And Electrolytes Flashcards
What is an electrolyte?
A compound that dissociates in water to form ions; includes acids, bases, and salts.
What types of compounds are electrolytes?
Inorganic acids, inorganic bases, and salts.
Why do electrolyte solutions conduct electricity?
Because they contain ions.
What are non-electrolytes?
Organic compounds with covalent bonds that do not dissociate in water.
What are the four main functions of electrolytes?
Maintain fluid balance, acid-base balance, generate electrical currents, act as enzyme cofactors.
What are the two major fluid compartments of the body?
Intracellular fluid (2/3) and extracellular fluid (1/3).
What are the two components of extracellular fluid?
Plasma (20%) and interstitial fluid (80%).
What are the major extracellular electrolytes?
Na+ (major cation), Cl- (major anion), bicarbonate, and plasma protein anions.
What are the major intracellular electrolytes?
K+ (major cation), phosphate (major anion), Mg2+, and protein anions.
What maintains the sodium and potassium gradients across membranes?
Na+/K+ ATPase pump.
What causes resting membrane potential?
Na+/K+ pump, trapped protein anions, and greater K+ membrane permeability.
What is an acid?
A substance that dissociates in water to release H+.
What is a base?
A substance that accepts H+, removing it from solution.
What is the pH scale?
A logarithmic scale from 0–14 that measures H+ concentration.
What is a salt in terms of electrolytes?
An ionic compound that dissociates in water but does not release H+ or OH-.
What is a buffer?
A solution that resists changes in pH by reacting with added acids or bases.
What are the three mechanisms of pH balance?
Chemical buffers (immediate), respiratory system (1–3 min), renal system (hours to days).
How does the carbonic acid-bicarbonate buffer system work?
H2CO3 reacts with bases, HCO3– reacts with acids to resist pH changes.
What does the respiratory system regulate to control pH?
The level of CO2 in the blood via ventilation rate.
How do the kidneys regulate blood pH during acidosis?
Secrete H+ and reabsorb bicarbonate.
What is respiratory acidosis?
pH < 7.35 due to impaired CO2 removal (e.g. asthma, brainstem damage).
What is metabolic acidosis?
pH < 7.35 due to increased H+ or loss of bicarbonate (e.g. ketoacidosis, diarrhea).
What is respiratory alkalosis?
pH > 7.45 caused by hyperventilation (e.g. anxiety, high altitudes).
What is metabolic alkalosis?
pH > 7.45 due to increased bicarbonate (e.g. vomiting, excess antacids).
