Physioex 6

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Danielle Rollins Cardiovascular Physiology Activity 1 1) Explain why the larger waves seen on the oscilloscope represent ventricular contraction. The ventricular contraction is when the blood is sent through the whole body as opposed to the atrial contraction that sends the blood to the heart and lungs. 2) Explain why the amplitude of the wave did not change when you increased the frequency of the stimulation. (Hint: relate your response to the refractory period of the cardiac action potential) How well did the results compare with your prediction? The threshold doesn’t change because after the voltage was simulated the cardiac muscle cells Ca channels opened. You cannot open them anymore or reopen them before depolarization.…show more content…
Also, perhaps the arms raised data 2013 may have had an immediate reading after raising the arms causing a higher difference in data to 2009. QUESTIONS: You may either use your data or the example data to answer each question below. Please remember to refer to the specific numbers involved (e.g. if you are talking about your measured BPM, please quote the BPM you recorded). 4. What does “end of T to R” represent? Why is end of T to R usually longer? (1pt) This represents the repolarization of the T wave to the depolarization of the R wave. This is usually longer because the heart has to then start another cardiac cycle from the beginning to the end of T. 5. What does the “R to R interval “represent? Why does is usually decrease when the arms are raised? (1 pt) this is the interval time measurement between the R wave of one heart beat and the R wave of the preceding heartbeat. Cardiac Output increases while adrenalin decreases as well as the heart rate decreasing. 6. Why do BPM normally decrease when arms are raised? (1 pt) Due to the change in venous return. 7. What does “R to bottom of pulse” represent? Why does this generally increase when arms are raised? (1 pt) The time frame it takes from R wave to R wave while looking at the pulse rate to see if it matches the heart rate which it should. This increases with arms raised due to the gravity pull of the blood return being easier to get
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