Body Fluid Compartments

These flashcards cover key vocabulary and concepts related to body fluid compartments, their composition, measurement methods, and regulatory mechanisms.

Intracellular Fluid (ICF)

Fluid contained within cells, making up approximately 66.67% of total body water.

Extracellular Fluid (ECF)

Fluid outside cells, making up approximately 33.33% of total body water, includes plasma and interstitial fluid.

Plasma Volume

The liquid component of blood, making up about 4-5% of body weight.

Interstitial Fluid

Fluid that exists in the space between cells, part of the extracellular fluid.

Hydrostatic Pressure

The pressure exerted by a fluid at rest; important in fluid exchange at capillaries.

Colloid Osmotic Pressure (Oncotic Pressure)

The pressure exerted by plasma proteins in the blood that tends to pull water into the circulatory system.

Starling Forces

Forces that determine the movement of fluid across capillary membranes based on hydrostatic and oncotic pressures.

Volume Measurement Principle

Dilution principle used to measure the volume of body fluid compartments by knowing the concentration of a substance.

Dye Dilution Method

A method for measuring plasma volume involving the injection of a dye that binds to plasma proteins.

Electrolytes in Body Fluids

Charged ions such as Na+, K+, and Cl- that play crucial roles in cellular function and fluid balance.

Tritiated Water (D2O)

A tracer used to measure total body water because it freely crosses cell membranes.

Fluid Compartments

Different areas in the body where fluids are distributed, including intracellular and extracellular spaces.

Barrier Between Fluid Compartments

Plasma membrane that controls the movement of substances between intracellular and extracellular fluids.

Passive Transport

Movement of substances across a cell membrane without the use of energy, often down a concentration gradient.

Active Transport

Energy-requiring process of transporting substances across a membrane against a concentration gradient.