Marker that diffuses freely not only in the water outside the cells but also crosses the cell membrane to reach the intracellular fluid. If you measure too soon all you will get is the volume of the functional extracellular fluid.
Neet Pg Physiology Mcqs Body Fluid Distribution And
Measurement of body fluids. 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. 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. Unfortunately some bromine 82 also distributes into the cells. A known amount of a substance the indicator which should be confined to the compartment of interest is administered. The indicator dilution method can be used to determine the size of body fluid compartments see chapter 14.
After allowing sufficient time for uniform distribution of the indicator throughout the compartment a plasma sample is collected. Body fluid compartments and measurement general physiology duration. Measurement of body fluid volumes total body water is measured using dilution principle. The vortices trail behind the cylinder alternatively from each side of the bluff body. If plasma is x and its volume in body is y then plasmahematocrit100 the volume in body is v. As the fluid passes this bar disturbances in the flow called vortices are created.
Measuring the extracellular fluid volume with crystalloid tracer. 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. Measurement of fluid volumes in the different body fluid compartmentsthe indicator dilution principle. Another method of flow measurement involves placing a bluff body called a shedder bar in the path of the fluid. Thus bromine measurements of the ecf volume frequently over estimate the ecf volume. A marker is injected that will be evenly distributed in all the compartments of body fluids.
Physiology open 1205 views. 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.
Gallery of Measurement Of Body Fluids
