Lecture 2- Internal Environment of the Body

Front

What are the two main compartments of body fluids?

Back

Intracellular fluid (ICF) and Extracellular fluid (ECF).

Front

What is homeostasis?

Back

The relative constancy of the internal environment despite changes in the external environment.

Front

What percentage of body weight do body fluids constitute in a lean adult?

Back

Approximately 55%–60%.

Front

What is the average total body water (TBW) for a lean adult male?

Back

TBW = Body weight – [protein + mineral + lipid].

Front

What is the composition of Extracellular Fluid (ECF) in terms of sodium (Na+) concentration?

Back

150 mM.

Front

What is the average plasma volume for a 70-kg male?

Back

Approximately 3500 mL.

Front

How is blood volume calculated?

Back

Total blood volume = 100 x Plasma volume / (100 - hematocrit).

Front

What is the proportion of blood consisting of packed red blood cells (RBC) for males?

Back

45%.

Front

What is the volume of distribution formula?

Back

Volume of distribution = The amount of injected substance - The amount removed by the body / Concentration of substance in sample.

Front

What is the ECF volume in a 70-kg male?

Back

Approximately 14L, which is 20% of total body weight.