1. Explain why the larger waves seen on the oscilloscope represent ventricular contraction. 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 3. Why is it only possible to induce an extrasystole during relaxation? 4. Explain why wave summation and tetanus are not possible in cardiac muscle tissue. How well did the results compare your prediction?

1. Explain why the larger waves seen on the oscilloscope represent ventricular contraction. 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 3. Why is it only possible to induce an extrasystole during relaxation? 4. Explain why wave summation and tetanus are not possible in cardiac muscle tissue. How well did the results compare your prediction?

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

See similar textbooks

Similar questions

1. Age-related changes in the heart’s electrical conduction system such as fibrosis and loss of specialized cells and fibers in the SA node and fibrosis of AV node and left anterior fascicle contribute to the development of (choose all that apply): a. Normal heart rate at rest b. Increase in atrial ectopy (irregular, rapid heartbeats) c. Increase in episodes of bradycardia (slow heart rate) d. Increased incidence of heart block. 2. Describe 3 age-related changes in the lungs that have a negative impact on preventing lung infections.
1. What are some examples of arrhythmias that can be seen on a rhythm strip? 2. What additional information do we get from a 12-lead that is not available on a simple rhythm strip? 3. What are the three types of acute coronary syndrome
16. The T-wave in the electrocardiogram above is caused by: repolarization of the ventricles, caused by K+ ions leaving ventricular muscle cells depolarization of the ventricles, caused by Na+ ions leaving ventricular muscle cells repolarization of the atria, caused by K+ ions leaving atrial muscle cells depolarization of the atria, caused by Na+ ions leaving atrial muscle cells
4. A change in pulse pressure can be seen in a variety of medical conditions. What would you expect to happen to the pulse pressure in the following examples? a. In atherosclerosis there is a hardening of the arterial walls. Explain b. A damaged aortic semilunar valve does not seal properly and allows blood to flow back into the ventricle during diastole. Explain EXTENSIONS 1. Exercise for varying lengths of time and compare the blood pressure and pulse readings taken after each exercise period. You can run around the building, and attach the cuff upon returning. 2. Perform different types of exercise for the same amount of time and compare the blood pressure and pulse readings taken after each type of exercise. 3. Measure blood pressure 5, 10, and 15 minutes after stopping exercise, and compare readings as your heart returns to resting heart rate. 4. Measure blood pressure while lifting a weight with the opposite arm.
8
4. This is not and will not be graded
10. Which of the following explains how you can find the cardiac output volume? a. Subtract the number of heart beats in one minute from the stroke volume. b. Add the number of heart beats in one minute to the stroke volume. c. Multiply the number of heart beats in one minute by the stroke volume. d. Divide the number of heart beats in one minute by the stroke volume.
Using Figure 4 as a reference, explain whether there was a difference in the resting heart rates of athletes and non-athletes. Explain the physiology behind your results in terms of the relationship between heart rate and stroke volume
1. You should be able to distinguish two heart sounds. The first sound is when the ventricle begins contracting (ventricular systole) the atrioventricular valves snap shut. This closing produces a low-pitched sound, the "lub" sound. The atrioventricular valves close when the ventricles contract due to pressure coming from the blood in the: Group of answer choices veins ventricles arteries atria 2. The "lub" sound is accompanied by the pulmonary and aortic (semilunar) valves opening. This, too, happens when the ventricles contract. These valves open due to pressure of the blood coming from the: Group of answer choices atria ventricles arteries veins 3. The second sound you hear in the heartbeat is when the ventricles begin to relax (diastole). The closing of the pulmonary and aortic (semilunar) valves produces a sound, the "dub" sound. These valves close when the ventricles relax due to the pressure of the blood coming from the: Group of answer choices atria…
2. How is an action potential in a contractile cardiac cell different from action potential in a pacemaker cell? (Write the phases and the channels involved for each phase).
10. Segment representing the time heart muscle is electrically silent 18. Waveform representing total ventricular SYSTOLE 19. Repolarization of the atria is found within which wave 20. Firing of the AV node occurs at the apex of which wave 19. Repolarization of the atria is found within which wave 20. Firing of the AV node occurs at the apex of which wave
Only one is correct Contraction of cardiac muscle is initiated during which phase of the fast action potential? What ion mediates this effect? A. Phase 0 due to Ca++ entry B. Phase 1 due to Na+ entry and K+ exit C. Phase 2 due to Ca++ entry D. Phase 4 due to K+ exit Group of answer choices Phase 2 due to Ca++ entry Phase 1 due to Na+ entry and K+ exit Phase 0 due to Ca++ entry Phase 4 due to K+ exit