Q1 Body Fluid Compartments

What is the total volume of body water?

40L

What is the volume of intercellular fluid (ICF)

25L

What is the volume of extracellular fluid (ECF)?

15L

What is the volume of interstitial fluid (ISF)?

12L

What is the volume of blood (plasma)?

3L

Which compartment makes up 40% of the total body weight?

ICF

What makes up 20% of the total body weight?

ECF

What makes up 80% of the ECF?

ISF

What makes up 20% of the ECF?

Plasma

Determining Volume of Body Fluid Compartments

Volume of Compartment = Amount of Tracer Added/Concentration of Tracer

Determining Volume of Body Fluid Compartments (Accounting for Excretion)

Volume of Compartment = (Amt. Added - Amt. Excreted) / Concentration of Sample

Total Body Water Indicator

Antipyrine and tritiated water

Intracellular Fluid Indicator

No indicator

Extracellular Fluid Indicator

Mannitol and inulin

Total Blood Volume Indicator

Radioactive RBCs

Plasma Volume Indicator

Evan’s blue and radioactive albumin

Hematocrit Equation

Volume of RBCs / Volume of blood

Volume of Blood Equation

Volume of Plasma / (1 - Hct)

Intracellular Calcium Ion Concentration

3mM

Intracellular Potassium Ion Concentration

150mM

Intracellular Sodium Ion Concentration

10mM

Intracellular Chloride Ion Concentration

2mM

Extracellular Calcium Ion Concentration

5mM

Extracellular Potassium Ion Concentration

4mM

Extracellular Sodium Ion Concentration

140mM

Extracellular Chloride Ion Concentration

105mM