Material and Methods:
Before the experiment began, Labscribe was loaded to the Cardiac Muscle Lab and the computer was connected to the iWorx unit that was set up with the iWorx Force Transducer clamped to a ring stand. A freshly euthanized frog was obtained from the instructor and was dissected to expose the beating heart of the frog. Any pericardial membrane still connected was removed and the heart was rinsed with Ringer’ solution (NaCl, KCl, MgCl2, CaCl2, a buffering agent, and deionized water). The dissection tray was moved about 15 cm under the force transducer. A metal pin hook was pierced through the ventricle of the frog and was tied and connected to the 10-gram hook on the transducer without too little or too much tension in the string, but just enough to lift the heart out of the chest cavity. Connective tissue was removed to let the heart beat independently. …show more content…
Effects of Temperature
This exercise just needed heartbeat recordings, so no parameters are needed. “Room Temperature Ringer’s” was typed into the Mark box. The heartbeat was recording for 30 seconds then ten drops of room temperature Ringer’s solution was dropped onto the heart then was marked. The heart rate was recorded for 20 more seconds. Then, chilled Ringer’s was obtained and “Cold Ringer’s” typed into the Mark box. After the 20 seconds of room temperature Ringer’s, 5 drops of the chilled Ringer’s was added and marked. The heart rate was recorded until the heart recovered from the effects of the chilled solution.
Next, the effects of warm Ringer’s solution would be determined. “Room Temperature Ringer’s” was entered into the Mark box. After 30 seconds of recording the heart rate, 10 drops of room temperature Ringer’s was added. Microwaved Ringer’s solution was obtained and 5 drops were dropped on the heart and was marked “Warm Ringer’s,” The heartbeat was recorded until the effects of the Ringer’s solution wore off. The chest cavity was then flushed with room temperature