Physioex 8.0 For Human Physiology

Here's what I have for activity 1 and 2.

Activity 1: Recording Baseline Frog Heart Activity (p. 75)

2. 62 bpm

Activity 2: Investigating the Refractory Period of Cardiac Muscle (pp. 75–76)

3. It is possible to induce an extrasystole in the relaxation part of the cardiac cycle.
4. The heart can not be tetanized by multiple stimuli.
Tetanization would make the heart ineffective as a pump.

Here is what i have to PhysioEx 8.0 Physiology
Activity 1: DIrect Heart Stimulation
1. Did you see any changes in the trace? NO
2. Why/ Why not? It needs more stimulation
3. DId you see any changes in the trace? Yes
Why/ Why not? There is double stimulation
4. Describe the change you see in the trace. How does it differ from the baseline trace? It increased in comparison to the baseline trace
5. What effect do the repeated stimuli have on the heartbeat trace? It stopped the heartbeat
6. What part of the trace shows the refractory period? atrial contraction
7. Does summation occur? no
8. Why is it important that summation not occur in heart muscle? Heart muscle contractions would increase leading to a heart attack.


Let me know if you need activity 2: Vagus Nerve Stimulation

do you have the answers to the review sheet?