EXERCISE 6: CARDIOVASCULAR PHYSIOLOGY
|ACTIVITY 1: Investigating the Refractory Period of |Answers | |Cardiac Muscle | | |Which of the following types of muscle tissue can depolarize spontaneously in the |C- Cardiac Muscle | |absence of any external stimulation: | | |Skeletal muscle | | |Smooth muscle | | |Cardiac muscle | | |All of the above | | |Look at Figure 6.1, the cardiac action potential. The period of time between the |Absolute refractory period of cardiac muscle | |beginning of the cardiac action potential and the approximate middle of phase 3 is | | |the __________________ refractory period of cardiac muscle. | | |In this simulation, when you delivered several single stimuli very rapidly, you saw a|Extrasystole | |double peak. The second peak is called an ______________. | | |True or False: In order for the heart to function the most effectively in pumping |TRUE | |blood, the ventricles must contract and then relax fully with each beat. | | |Explain why the larger waves seen on the oscilloscope represent ventricular |The ventricles are larger chambers therefore, when they contract they generate more | |contractions. |force thus producing a larger wave. | |Explain why the amplitude of the wave did not change when you increased the frequency|The amplitude did not change because of the long absolute refractory period of | |of the stimulation. |cardiac muscle tissue which insures that the extrasystole doesn’t occur during | | |contraction. | |Why is it only possible to induce an extra systole during relaxation. (HINT: Relate |The stimulus applied during relaxation should cause an extra systole because it was | |your response to the refractory period of the cardiac action potential.) |applied when the cells were re-polarizing. | |Explain why wave summation and tetanus are not possible in cardiac muscle tissue. |Wave summation and tetanus are not...
Please join StudyMode to read the full document