Deck 2: Homeostasis of Body Fluids

Question 1

Three individuals,each weighing 55 kg and each having a plasma [Na⁺] of 145 mEq/L,receive infusions of different solutions.Individual A receives 1 L of isotonic NaCl (290 mOsm/kg H₂O); individual B receives 1 L of a mannitol solution (290 mOsm/kg H₂O); and individual C receives 1 L of a 5% dextrose in water (D₅W)solution (290 mOsm/kg H₂O).Assuming that there is no urine output,and after complete equilibration of the extracellular and intracellular fluid,which of these individuals will have a lower plasma [Na⁺]?

A)Individual A (NaCl infusion).
B)Individual B (mannitol infusion).
C)Individual C (D₅W infusion).
D)Individuals A,B,and C will have the same plasma [Na⁺].

Answer 1

B

Question 2

Intravenous infusion of 2 L of which of the following solutions will lead to the largest increase in intracellular fluid volume?

A)D₅W
B)Isotonic NaCl
C)Hypotonic NaCl
D)Hypertonic NaCl

Answer 2

A

Question 3

Intracellular fluid volume is normally what percentage of body weight?

A)60%
B)40%
C)20%
D)10%
E)5%

Answer 3

B

Question 4

A 100 mmol/L solution of MgCl₂ would be expected to have an osmolality of which of the following?

A)50 mOsm/kg H₂O
B)100 mOsm/kg H₂O
C)200 mOsm/kg H₂O
D)300 mOsm/kg H₂O
E)350 mOsm/kg H₂O