Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 31

Which of the following would contribute the most to a urine osmolality?

A. One osmole of glucose

B. One osmole of urea

C. One osmole of sodium chloride

D. All contribute equally

Step 1 of 2

Osmolarity:

The concentration of the solution uttered as total number of solute particles per liter.

Urine osmolarity:

• This detects the water balance of body and urine concentration.

Osmole:

Mole in solution which contributes to the osmotic pressure of a solution.

• Potassium, chloride, sodium, bicarbonate, urea, glucose are solutes of body fluid.

• Both sodium and chloride contributes to the osmolarity of urine in one osmole.

• Sodium has molecular weight of 23.

• Chloride has 35.5 as molecular weight.

Therefore, “one osmole sodium chloride” contributes most to urine osmolarity. Hence, the correct answer is option .