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• Lesly Castellano

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Exercise 5: Cardiovascular Dynamics: Activity 6: Studying the Effect of Stroke Volume on Pump Activity Lab Report Pre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly. 1. Which of the following variables directly contributes to preload? You correctly answered: b. venous return 2. Which of the following would not increase end diastolic volume? You correctly answered: c. dehydration 3. Increased contractility of the heart results in all but which of the following? You correctly answered: d. increased end systolic volume 4. Which of the following does not affect stroke volume? You correctly answered: d. All of these affect stroke volume. 5. Which of the following is not equivalent to the others? You correctly answered: c. end diastolic volume

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Experiment Results Predict Question: Predict Question: If the pump rate is analogous to the heart rate, what do you think will happen to the rate when you increase the stroke volume? Your answer : a. The pump rate will decrease to maintain cardiac output. Stop & Think Questions: Why did changing the ending pump volume (ESV) automatically change the stroke volume? You correctly answered: d. The heart intrinsically alters stroke volume to accommodate changes in preload. The flow has stayed constant with each trial because You correctly answered: a. cardiac output is equivalent to blood flow. How does the heart provide for an increase in stroke volume? You correctly answered: b. by increasing contractility Experiment Data: Flow (ml/min) 5086.8 5086.8 5086.8 5086.8 5086.8 5086.8 5086.8 5086.8

Rad. L (mm) 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0

Rad. R (mm) 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0

Str. V (ml) 10 20 30 40 50 60 80 100

Rate (strokes/min) 508.7 254.3 169.6 127.2 101.7 84.8 63.6 50.8

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Press. L (mm Hg) 40 40 40 40 40 40 40 40

Press. Dif. R (mm Hg) 40 40 40 40 40 40 40 40

Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. What do you think would happen when stroke volume is decreased? You correctly answered: b. Pump rate would increase. 2. Why might an athlete's resting heart rate be lower than that of the average person? You correctly answered: e. Stroke volume and contractility have increased. 3. In this activity, which of the following stayed constant? You correctly answered: c. flow rate 4. Which of the following is true? You correctly answered: d. ESV = EDV - SV

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Review Sheet Results 1. Describe the Frank-Starling law in the heart. Your answer: Cuando el sistema venoso devuelve al corazón un volumen de sangre superior al normal, el músculo cardíaco se estira, lo que da por resultado una contracción más fuerte de los ventrículos. 2. Explain what happened to the pump rate when you increased the stroke volume? Why do you think this occurred? How well did the results compare with your prediction? Your answer: La velocidad de bombeo se redujo a mantener el gasto cardíaco como predicción. El volumen sistólico y la frecuencia de la bomba son el factor de cardiaco de salida. 3. Describe how the heart alters stroke volume. Your answer: Al cambiar la contractilidad del corazón puede alterar el volumen sistólico. 4. Describe the intrinsic factors that control stroke volume. Your answer: La contractilidad puede controlar el volumen sistólico y la precarga puede controlar el volumen sistólico también. La contractilidad es la fuerza que la muscular crear en la longitud dada. La precarga da el volumen de sangre que el ventrículo tiene disponible para bombear.

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