Explan why the larger waves seen on the oscilloscope represent ventricular contraction
| the ventricle contraction is of greater force than the atrial contraction, this is due to the fact that ventricle's fxn is to send blood throughout the body.
| Explain why the amplitude of the wave did not change when you increased the frequency of the stimulation in cardiac muscle.
| amplitude does not change because the cardiacs long refractory period prevents summation.
| Why is it only possible to induce an extrasystole during relaxation?
| the extrasystole can not occur until relaxation and so we could not achieve wave summation tetanus
| Explain why wave summation and tetanus are not possible in cardiac muscle tissue.
| Cardiac cells have longer APs and twitches than any other muscle cells,therefore they do not show temporal summation
| explain the effect that extreme vagal stimulation had on the heart.
| the HR decreases and stopped the heart temporarily
| Explain two ways that the heart can overcome excessive vagal stimulation.
| 1: Sympathetic reflexes 2: initiation of a rhythm by the Purkinje Fibers
Describe how the sympathetic and parasympathetic nervous system work together to regulate heart rate
| Sympathetic increases HR Parasympathetic decreases HR
What do you think would happen to the HR if the vagus nerve was cut?
| It would increase and go back to the 100bpm
| Explain the effect that decreasing temperature had on the frog heart.
| It slows the HR
| Describe why Ringer's solution is required to maintain heart contractions.
| it contains all the ions, pH, glucose, ATP need to keep the heart beating.
| Explain the effect that increasing the temperature had on the frog heart.
| it increase the HR
| describe the effect that pilocarpine had on the heart and why it had this effect
| -It decreases the HR -it stimulates the parasympathetic nerves
Atropine is an acetylcholine antagonist. Does atropine inhibit or enhance the...
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