an interactive computer simulation of experiments to study the renal function in humans

by David Dewhurst, John Atherton and Stewart Cromar

This highly interactive computer program is designed to allow students to collect urine and plasma data from groups of healthy male students who took part in the following investigations:

1. control experiment (no water loading)

2. water loading experiment

3. experiments to investigate the action of four diuretics (acetazolamide, amiloride, hydrochlorothiazide, bumetanide) in water loaded subjects

For each experiment, data are presented (mean values: n=10) graphically for:

Students observing data from water-loaded subjects may superimpose control data to give a visual comparison. Similarly, water-loading data can be superimposed for each of the diuretic experiments.

The program also describes the protocol for each experiment and, in brief, the methods used to analyse urine and plasma. Accompanying each experiment are several interactive questions and tasks to emphasise the important physiological principles. These may be questions (e.g. multiple choice or true false with feedback), data interpretation exercises, or calculations. For example, for each experiment and in addition to other questions, students are asked to calculate using data they have collected from the program: glomerular filtration rate; total and fractional (%) water re-absorption; total and fractional (%) Na⁺ re-absorption. The calculations require them to take measurements from the graphical screen displays, enter it into well-established formulae and type in their answers. Assistance with the calculations is available via an on-screen "Help" and, if they get the answer incorrect, there is also a "Tell" facility which demonstrates how the correct answer is arrived at. These questions are designed to consolidate knowledge and to allow students to self-assess their understanding of the section they have completed. A summary of all other data, which may be calculated, is also incorporated.