Post-exercise Post-exercise 60 s Post-exercise 120 s Post-exercise Post Lab Ques
ID: 3513532 • Letter: P
Question
Post-exercise Post-exercise 60 s Post-exercise 120 s Post-exercise Post Lab Questions 7. How is heart rate controlled by the nervous system? 8. What happened to the R-R interval and heart rate after exercise? 9. Immediately after exercise (Exercise 2), was the amplitude of the pulse smaller or larger than during the resting period? 10. Immediately after hand exercise (Exercise 3), was the amplitude of the pulse smaller 11. What happened to the blood volume pulse amplitude during recovery from hand or larger than during the resting period? exercise? Calculate cardiac output for an athlete with HR = 40 BPM and SV = 0.125 L. How would valvular stenosis (narrowing) of the atrioventricular valves affect ejection 12. 13. of blood from the heart? 14. Based on your understanding of heart and muscle function, why would it be necessary for a patient to be as still as possible while recording the ECG?Explanation / Answer
7. The autonomic nervous system controls the heart rate. The heart is supplied by sympathetic and parasympathetic branches. Sympathetic innervation increases the heart rate. The autonomic nervous system is controlled by the hypothalamus.
8. R-R interval in ECG depicts the heart rate. As the heart increases with exercise R-R interval decreases. This change in R-R interval is called heart rate variability.
9. Pulse amplitude is smaller immediately after exercise than during recovery phase.
10. Immediately after hand exercise, pulse amplitude changes relatively little.
11. Vasodiation occurs. Pulse amplitude increases.
12. CO = stroke volume x heart rate
CO = 40x 0.125 = 5L