Thu18November0303AM 7
In a normal adult woman weighing 60 kg which of the following is true about the extracellular fluid (ECF)?
(Please select 1 option)
Has a total volume of about 12 litres Correct
Contains no protein
Is isotonic throughout the body
Has a sodium concentration of 125-135 mmol/L
Forms a greater proportion of the total body weight in the obese than in the lean woman
Explanation
Total body water is about 60% of body weight (50% to 70% depending on how much fat is present). In the obese ECF is relatively contracted.
In this person total body water is approximately 36 litres (0.6 × 60), of which 1/3 is ECF (12 litres) and 2/3 (24 litres) intracellular fluid.
The simple rule is 60-40-20.
Normal sodium concentration is approximately 135-145 mmol/L.
ECF is composed of intravascular fluid and extravascular fluid. Both contain plasma proteins.
Answer Statistics
1
51%
2
1%
3
19%
4
11%
5
20%
Times answered: 249