Question

The intracellular fluid volume including those of the blood cells is approximately

• A. 15 litres
• B. 20 litres
• C. 27 litres
• D. 35 litres

Answer 1

The Correct Option is C

The question asks about the approximate volume of intracellular fluid (ICF) in the human body, inclusive of the fluids within blood cells. To determine the correct answer, we need to understand the distribution of total body fluid.

• Total Body Water (TBW): This is about 60% of body weight in adults. For a 70 kg adult, this would be around 42 litres.
• Intracellular Fluid (ICF): This constitutes about two-thirds of the TBW. It represents the fluid contained within all the body's cells.
• Extracellular Fluid (ECF): This makes up the remaining one-third of TBW and includes interstitial fluid and plasma.

Now, calculating the ICF volume: 

• ICF Volume = 2/3 × TBW
• Using TBW = 42 litres (for a standard 70 kg adult), we have:
• \(\text{ICF Volume} = \frac{2}{3} \times 42 \text{ litres} = 28 \text{ litres}\)

However, when considering approximations given in the options, the closest choice to the standard estimation is 27 litres. It reflects a generalized value considering most adult variations.

Thus, the correct answer is: 27 litres.

This understanding can help in exam scenarios by knowing the key breakdown of body water distribution, which is a fundamental concept in pathophysiology.