Measurement of fluid volumes in the different body fluid compartmentsthe indicator dilution principle. Extracellular fluid volume measurement is difficult to measure because the limits of this space are difficult to define and because few substances mix rapidly in all parts of the space while remaining extracellular.
Cancer Biomarkers In Body Fluids Biomarkers In Proximal
Measurement of body fluids. Not interfere with body fluid distribution if the tracer is excreted in the urine then the loss can be determined and corrections made in the calculation. Determination of cardiac output ficks principle dye dilution method to assess. Another method of flow measurement involves placing a bluff body called a shedder bar in the path of the fluid. Physiology open 1205 views. If plasma is x and its volume in body is y then plasmahematocrit100 the volume in body is v. Body fluid compartments and measurement general physiology duration.
Marker that diffuses freely not only in the water outside the cells but also crosses the cell membrane to reach the intracellular fluid. If the tracer is metabolised a series of measurements can be made and assuming exponential decline first order kinetics the volume of distribution can be determined by extrapolation back to zero time. Thus bromine measurements of the ecf volume frequently over estimate the ecf volume. The vortices trail behind the cylinder alternatively from each side of the bluff body. After allowing sufficient time for uniform distribution of the indicator throughout the compartment a plasma sample is collected. A known amount of a substance the indicator which should be confined to the compartment of interest is administered.
Measurement of body fluid volumes total body water is measured using dilution principle. Unfortunately some bromine 82 also distributes into the cells. As the fluid passes this bar disturbances in the flow called vortices are created. The indicator dilution method can be used to determine the size of body fluid compartments see chapter 14. If you measure too soon all you will get is the volume of the functional extracellular fluid. The volume of a fluid compartment in the body can be measured by placing an indicator substance in the compartment allowing it to disperse evenly through out the compartments fluid and then analyzing the extent to which the substance becomes diluted.
A marker is injected that will be evenly distributed in all the compartments of body fluids. Measuring the extracellular fluid volume with crystalloid tracer.
Gallery of Measurement Of Body Fluids
