FLUID AND ELECTROLYTES EXAM REVIEW
GUIDE 2026 COMPLETE PRACTICE
QUESTIONS AND ANSWERS
●● What does extracellular fluid include? Answer: Interstitial fluid +
Plasma (and small amount transcellular)
●● What is the fluid that surrounds the cells called? Answer: Interstitial
fluid
●● What is the chief mechanism for maintaining fluid balance? Answer:
Regulate intake and output (mainly via kidneys)
●● Which organ has the greatest effect on fluid output? Answer:
Kidneys
●● What hormone reduces the amount of water in the body? Answer:
Atrial natriuretic peptide (ANP)
●● What hormone increases the amount of water in the body? Answer:
Antidiuretic hormone (ADH)
, ●● What happens when dehydration begins to occur? Answer: Thirst
mechanism is stimulated
●● What are electrolytes? Answer: Substances that dissociate into ions
in water and conduct electricity
●● What is the most abundant positive ion in blood plasma? Answer:
Sodium (Na⁺)
●● What is the most abundant negative ion in blood plasma? Answer:
Chloride (Cl⁻)
●● Which electrolyte is important in hemoglobin production? Answer:
Iron (Fe)
●● Which electrolyte is important in the formation of thyroid hormones?
Answer: Iodine (I)
●● What is the main protein in blood plasma? Answer: Albumin
●● What is the most important regulator of sodium in the body? Answer:
Aldosterone
GUIDE 2026 COMPLETE PRACTICE
QUESTIONS AND ANSWERS
●● What does extracellular fluid include? Answer: Interstitial fluid +
Plasma (and small amount transcellular)
●● What is the fluid that surrounds the cells called? Answer: Interstitial
fluid
●● What is the chief mechanism for maintaining fluid balance? Answer:
Regulate intake and output (mainly via kidneys)
●● Which organ has the greatest effect on fluid output? Answer:
Kidneys
●● What hormone reduces the amount of water in the body? Answer:
Atrial natriuretic peptide (ANP)
●● What hormone increases the amount of water in the body? Answer:
Antidiuretic hormone (ADH)
, ●● What happens when dehydration begins to occur? Answer: Thirst
mechanism is stimulated
●● What are electrolytes? Answer: Substances that dissociate into ions
in water and conduct electricity
●● What is the most abundant positive ion in blood plasma? Answer:
Sodium (Na⁺)
●● What is the most abundant negative ion in blood plasma? Answer:
Chloride (Cl⁻)
●● Which electrolyte is important in hemoglobin production? Answer:
Iron (Fe)
●● Which electrolyte is important in the formation of thyroid hormones?
Answer: Iodine (I)
●● What is the main protein in blood plasma? Answer: Albumin
●● What is the most important regulator of sodium in the body? Answer:
Aldosterone
