Cardiovascular Physiology Ex 6 Act. 1, 2, 3, 4 and 5

3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Due: 11:59pm on Tuesday, March 2, 2021 PhysioEx Exercise 6 > Activity 1: Overview and Pre-lab Quiz for Investigating the Refractory Period of Cardiac Muscle Read the introduction and then answer the Pre-lab Quiz questions to the right. Exercise 6 > Activity 1: Investigating the Refractory Period of Cardiac Muscle Part A The autorhythmicity of cardiac pacemaker cells is made possible by the reduced permeability of _______. ANSWER: potassium sodium calcium magnesium Correct Part B The repolarization of cardiac muscle is due to _______. ANSWER: 1/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 sodium exiting the cell sodium entering the cell potassium exiting the cell potassium entering the cell Correct Part C The total refractory period of cardiac muscle _______. ANSWER: is longer than the total refractory period for skeletal muscle is longer than the contraction of cardiac muscle is shorter than the total refractory period for skeletal muscle is about the same as the total refractory period for skeletal muscle Correct Part D Skeletal muscle is capable of which of the following? ANSWER: fused tetanus wave summation, fused tetanus and autorhythmicity wave summation and fused tetanus autorhythmicity wave summation Correct PhysioEx Exercise 6 > Activity 1: Activity and Post-lab Quiz for Investigating the Refractory Period of Cardiac Muscle 2/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Click on the link or the image below to launch Exercise 6 > Activity 1: Investigating the Refractory Period of Cardiac Muscle. Complete the Experiment and then answer the Post-lab Quiz questions to the right. Exercise 6 > Activity 1: Investigating the Refractory Period of Cardiac Muscle Part A Delivering single shocks in succession to stimulate the frog heart _______. ANSWER: did not increase the height of the ventricular systole wave resulted in wave summation resulted in fused tetanus increased the height of the ventricular systole wave Correct Part B The doublet that results with more frequent stimulation of the frog heart represents _______. ANSWER: 3/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 an extrasystole and an extra contraction of the ventricles an extrasystole and an extra contraction of the atria an extra contraction of the ventricles an extra contraction of the atria an extrasystole Correct Part C When the ventricles beat rapidly in succession, _______. ANSWER: wave summation occurred a compensatory pause followed a doublet representing two atrial contractions followed the second peak was higher than the first Correct Part D When multiple stimuli were applied at 20 stimuli/sec, _______. ANSWER: atrial contractions completely disappeared extrasystoles were produced fused tetanus occurred triplets representing three ventricular contractions occurred Correct PhysioEx Exercise 6 > Activity 2: Overview and Pre-lab Quiz for Examining the Effect of Vagus Nerve Stimulation Read the introduction and then answer the Pre-lab Quiz questions to the right. 4/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Exercise 6 > Activity 2: Examining the Effect of Vagus Nerve Stimulation Part A The effect of the sympathetic nervous system on the heart is to _______. ANSWER: decrease the heart rate increase the heart rate and increase the force of contraction increase the heart rate decrease the heart rate and decrease the force of contraction Correct Part B Which branch of the autonomic nervous system dominates after a large meal? ANSWER: the sympathetic branch Both parasympathetic and sympathetic branches dominate after a large meal. neither the parasympathetic nor the sympathetic branch the parasympathetic branch Correct 5/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Part C The sinoatrial node is located _______. ANSWER: outside the human heart in the right atrial wall of the human heart in the interventricular septum of the human heart in the left atrial wall of the human heart Correct Part D Excessive vagal stimulation of the heart will result in _______. ANSWER: a decrease in heart rate and, eventually, a temporary cessation of the heartbeat an increase in heart rate an increase in the force of contraction a decrease in the force of contraction Correct PhysioEx Exercise 6 > Activity 2: Activity and Post-lab Quiz for Examining the Effect of Vagus Nerve Stimulation Click on the link or the image below to launch Exercise 6 > Activity 2: Examining the Effect of Vagus Nerve Stimulation. Complete the Experiment and then answer the Post-lab Quiz questions to the right. Exercise 6 > Activity 2: Examining the Effect of Vagus Nerve Stimulation 6/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Part A When vagus nerve stimulation was applied to the frog heart, _______. ANSWER: the heart rate slowed and eventually stopped the force of contraction increased and the heart rate slowed and eventually stopped the force of contraction decreased the force of contraction increased the force of contraction decreased and the heart rate slowed and eventually stopped Correct Part B What part of your tracing illustrates vagal escape? ANSWER: the part where the heart rate slowed down the part where the heart stopped the part where the heart resumed beating the part where the force of contraction decreased Correct 7/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Part C Research shows that in the absence of neural and hormonal influences, the SA node generates action potentials at a frequency of about 100 times per minute. However, the resting heart rate is about 70 beats per minute. What would the approximate heartrate be if the vagus nerve were severed? ANSWER: about 100 beats per minute slower than 70 beats per minute faster than 100 beats per minute about 70 beats per minute Correct Part D Which of the following has the fastest rate of spontaneous depolarization? ANSWER: Purkinje fibers AV bundle branches the SA node the AV node Correct PhysioEx Exercise 6 > Activity 3: Overview and Pre-lab Quiz for Examining the Effect of Temperature on Heart Rate Read the introduction and then answer the Pre-lab Quiz questions to the right. Exercise 6 > Activity 3: Examining the Effect of Temperature on Heart Rate 8/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Part A Organisms that are poikilothermic _______. ANSWER: maintain their body temperature range even though the external temperature is changing have temperature fluctuations that coincide with the external temperature maintain their body temperature range even though the external temperature is changing and lack internal homeostatic temperature regulatory mechanisms have temperature fluctuations that coincide with the external temperature and lack internal homeostatic temperature regulatory mechanisms lack internal homeostatic temperature regulatory mechanisms Correct Part B Which part of the human body regulates temperature? ANSWER: the hypothalamus the anterior pituitary gland the heart the thyroid gland Correct 9/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 Part C Heat-releasing mechanisms include which of the following? ANSWER: vasoconstriction vasoconstriction and sweating vasodilation and sweating sweating vasodilation Correct PhysioEx Exercise 6 > Activity 3: Activity and Post-lab Quiz for Examining the Effect of Temperature on Heart Rate Click on the link or the image below to launch Exercise 6 > Activity 3: Examining the Effect of Temperature on Heart Rate. Complete the Experiment and then answer the Post-lab Quiz questions to the right. Exercise 6 > Activity 3: Examining the Effect of Temperature on Heart Rate Part A For the frog heart, temperature and heart rate are _______. ANSWER: 10/19 3/2/2021 Cardiovascular Physiology Ex 6: Act. 1, 2, 3, 4 and 5 directly proportional independent indirectly proportional controlled by homeostasis Correct Part B If the human heart were experiencing hyperthermia, what do you think would be the effect on the heart rate? ANSWER: The heart rate would decrease. The heart rate would increase. The heart rate would increase and then return to normal. The heart rate would not change. Correct Part C Ringer's solution contains which of the following? ANSWER: cations anions cations, anions and electrolytes electrolytes Correct PhysioEx Exercise 6 > Activity 4: Overview and Pre-lab Quiz for Examining the Effects of Chemical Modifiers on Heart Rate Read the introduction and then answer the Pre-lab Quiz questions to the right. Exercise 6 > Activity 4: Examining the Effects of Chemical Modifiers on Heart Rate 11/19