Abstract: Action Potential Experiments is a demonstration/simulation laboratory for neurophysiology based on the 'sodium theory' as originally formulated and tested by A. L. Hodgkin and his colleagues. The application includes simulations of the original experiments of Hodgkins and his colleagues, and of the classic voltage clamp and patch clamp experiments and an animated illustration of the 'sodium theory' explanation of Nernst potentials for potassium and sodium ions. The student can perform simple ion concentration experiments to test the predictions of the theory.
Abstract: The Cardiovascular Construction Kit (CVCK) allows students to design and construct a wide range of cardiovascular systems, testing each one to see how it behaves and whether it could actually exist and survive in a real organism. CVCK provides a set of basic components, e.g., pumps, vessels, capillaries and so on, which may be pieced together to construct a cardiovascular system. Gauges and measurement techniques are provided so you can draw conclusions from your experiments. Note: CVCK is a MAC Archive Module and requires System 6.05 to System 6.07.
To construct cardiovascular systems with CVCK, select components from the menu bars, drag them onto the main screen, and connect them together by making them touch.
CVCK makes it possible to construct experiments as well as systems. Such experiments allow comparisons of the performance of systems with different configurations or characteristics.
One constructs experiments by deciding what aspects of performance need to be measured and by hooking up gauges at appropriate places.
Gauges that can measure variables like pressure and blood flow can be connected to the components, and the values that are read from these gauges can be displayed in the form of a graph.
Abstract: The CFL simulation includes two models: the original Isolated Heart Lab, which models an isolated left ventricle, and a new Closed Circulation Lab
The Closed Circulation Lab models the entire circulatory loop: left ventricle, peripheral circulation, right ventricle, and pulmonary circulation.
Both models include numerous input parameters that can be controlled by the user. Some of these parameters are shown in Figures 1 and 2. By manipulating these physiological variables, students can design experiments to investigate a variety of questions concerning how changes affect the performance of the heart.
Abstract: The simulation program is based on the Nobel Prize winning Hodgkin-Huxley model for excitation of the squid axon. The program simulates an excised squid axon by applying stimuli or clamps after setting the environment of the axon, changing its properties, and/or adding drugs or toxins.
By using the program tools, experiments can be developed that explore a variety of nerve properties, ranging from classical phenomena such as threshold, summation, refractory period, and impulse propagation to more modern concepts of channels, gates, and eventually even molecular events.
The simulation provides insight into the hypothesized mechanisms of excitation in a way that is not practical with animal preparations. These ideas can be explored at both beginning and advanced levels. You can dive into a full blown propagating action potential with 15 recording electrodes or you can begin with an unexcitable axon and gradually patch in the component parts. In every case there are animations linked to the computations which will help interpret any experiment.