ANATOMY & PHYSIOLOGY 4/E PAC 1 SEMESTER
4th Edition
ISBN: 9781265061173
Author: McKinley
Publisher: MCG CUSTOM
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Textbook Question
Chapter 19, Problem 5CAL
During surgery, the right vagus nerve was accidently cut. Explain the effect to the heart rate.
- a. There is no change to the heart rate because the vagus nerve does not innervate the heart.
- b. The heart rate increases to the inherent rhythm of SA nodal cells.
- c. The heart stops beating, and heart rate becomes zero.
- d. The heart rate decreases to the inherent rhythm of SA nodal cells.
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Students have asked these similar questions
SA node is the main pacemaker of the heart. Why is the normal heart rate lower than the intrinsic firing rate of the SA node?
A. sympathetic inputs from the hypothalamus are slowing it down
B. parasympathetic inputs from medulla oblongata are slowing it down
C. there is inertia in heart muscle as it takes time for impulse to spread through all the cells
D. centrifugal inputs from the AV node are slowing it down
Which of the following is true of propagation of longitudinal electrical flow in cardiac muscle.
A.
Current flows longitudinally from a region of depolarization through ryanodine receptors.
B.
Longitudinal current flows through inward rectifier potassium channels.
C.
This current can be detected at the body surface, if the source is large enough.
D.
A and B.
E.
All are true.
Which of the following is not true for conduction of the cardiac impulse?
A. Action potentials propagate by current flow through gap junctions.
B. Slow propagation occurs as a result of low intercellular conductance.
C. Slow propagation requires a slower (sustained) current source (1.e. Ca).
D. Fast propagation occurs as a result of high intercellular conductance.
E. All are true.
Chapter 19 Solutions
ANATOMY & PHYSIOLOGY 4/E PAC 1 SEMESTER
Ch. 19.1 - Prob. 1WDYLCh. 19.1 - Prob. 2WDYLCh. 19.1 - Prob. 3WDYLCh. 19.1 - Prob. 4WDYLCh. 19.1 - Prob. 5WDYLCh. 19.2 - What is the bony structure that protects both the...Ch. 19.2 - Prob. 7WDYLCh. 19.2 - Prob. 8WDYLCh. 19.3 - Prob. 9WDYLCh. 19.3 - Prob. 10WDYL
Ch. 19.3 - Prob. 11WDYLCh. 19.3 - Prob. 12WDYLCh. 19.3 - Prob. 13WDYLCh. 19.3 - Prob. 14WDYLCh. 19.3 - Prob. 15WDYLCh. 19.3 - Prob. 16WDYLCh. 19.3 - What areas of the heart are deprived of blood when...Ch. 19.3 - Prob. 18WDYLCh. 19.4 - Prob. 19WDYLCh. 19.5 - Prob. 20WDYLCh. 19.5 - Which autonomic division is associated with the...Ch. 19.6 - Prob. 22WDYLCh. 19.6 - What is autorhythmicity? Describe how nodal cells...Ch. 19.6 - What is the path of an action potential through...Ch. 19.6 - What anatomic features slow the conduction rate of...Ch. 19.7 - In which direction does Ca2+ move in response to...Ch. 19.7 - What three electrical events occur at the...Ch. 19.7 - What is the significance of the extended...Ch. 19.7 - What events in the heart are indicated by each of...Ch. 19.8 - Pressure changes that occur during the cardiac...Ch. 19.8 - What is occurring during ventricular ejection?Ch. 19.8 - Prob. 32WDYLCh. 19.8 - Define end-diastolic volume, end-systolic volume,...Ch. 19.9 - What are the two factors that determine cardiac...Ch. 19.9 - What is the cardiac output at rest and during...Ch. 19.9 - Prob. 36WDYLCh. 19.9 - Describe the atrial reflex, which involves...Ch. 19.9 - Prob. 38WDYLCh. 19.9 - Prob. 39WDYLCh. 19.10 - What would be the path of blood flow through the...Ch. 19 - Which of the following is the correct circulatory...Ch. 19 - The pericardial cavity is located between the a....Ch. 19 - How is blood prevented from backflowing from the...Ch. 19 - ____ 4. Venous blood draining from the heart wall...Ch. 19 - _____ 5. Calcium channels in the nodal cells...Ch. 19 - ____6. Action potentials are spread rapidly...Ch. 19 - Why is it necessary to stimulate papillary muscles...Ch. 19 - ____ 8. Preload is a measure of a. stretch of...Ch. 19 - ____ 9. All of the following occur when the...Ch. 19 - ____10. What occurs during the atrial reflex? a....Ch. 19 - Prob. 11DYKBCh. 19 - Compare the structure, location, and function of...Ch. 19 - Prob. 13DYKBCh. 19 - Explain why the walls of the atria are thinner...Ch. 19 - Describe the structure and function of...Ch. 19 - Explain the general location and function of...Ch. 19 - Describe the functional differences in the effects...Ch. 19 - Prob. 18DYKBCh. 19 - List the five events of the cardiac cycle, and...Ch. 19 - Define cardiac output, and explain how it is...Ch. 19 - A young man was doing some vigorous exercise when...Ch. 19 - A young man was doing some vigorous exercise when...Ch. 19 - Prob. 3CALCh. 19 - Prob. 4CALCh. 19 - During surgery, the right vagus nerve was...Ch. 19 - Prob. 1CSLCh. 19 - Prob. 2CSLCh. 19 - Your grandfather was told that his SA node...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Contractions in the heart are controlled via a well-regulated electrical signaling cascade that originates in pacemaker cells in the _______ node and is passed via internodal atrial pathways to the ________, the __________, the___, and to all parts of the _________. A. sinoatrial node B. ventricle C. Purkinje system D. Bundle of His E. atrioventricular nodearrow_forwardCells in the body have the ability to undergo a transiet depolarization and repolarization. A. Plot the action potential of non-pacemaker cardiac myocyte and indicate what kinds of ion channels involved in each phase and compare ion movement during a myocardial cell's action potential to ion movement of a neuron's action potential. B.Explain why contractions in the cardiac muscle cells are different to skeletal muscle cells.arrow_forwardWhich of the following is true about the pacemaker potential in the heart? a. Decreased K+ efflux causes the resting membrane potential to increase b. Action potential occurs when T-type Ca2+ channels open c. Only the SA node in the heart has a pacemaker potential d. The atrioventricular node is needed to pace the sinoatrial node e. None of the options are truearrow_forward
- Which cell types are associated with spontaneous action potential generation in the absence of an external stimulus from other tissues. A. Sino-Atrial node cells (SA node). B. Atrial cells C. Ventricular cells. D. Endothelial cells. E. A and D.arrow_forwardThe pacemaker cardiac muscle cells rely on ______________ for their action potentials. a. Na+ leak channels and fast voltage-gated Na+ channels b. Ca+2 leak channels and slow voltage-gated Ca+2 channels c. Na+ leak channels and fast voltage-gated Ca+2 channels d. Ca+2 leak channels and fast voltage-gated Ca+2 channelsarrow_forwardVentricular cardiomyocytes under sympathetic drive during a bout of exercise... a. Would collectively make more force than at rest due to recruitment of more cardiomyocytes b. Would relax faster due to phosphorylation of the cardiac ryanodine receptors c. Would pump out more SV despite a decrease in EDV d. Would show an increased rate of myosin ATPase activity due to phosphorylation of the calcium ATPase pumps e. Would have elevated levels of cAMP and kinase activityarrow_forward
- Which of the following is not true for conduction of the cardiac impulse? A. Action potentials propagate by current flow through gap junctions. B. Slow propagation occurs due to high longitudinal resistance. C. Slow propagation requires a slower (sustained) current source (i.e. Ca). D. Fast propagation occurs as a result of high intercellular conductance. E. All are true.arrow_forwardDuring the ventricular ejection phase of the normal human cardiac cycle, one option is correct: a. ejection takes less time than filling, in a resting human. b. the left ventricle diameter increases and the ventricle elongates from base to apex. c. papillary muscles close the atrioventricular valves. d. the chordae tendineae are relaxed. e. the apex beat is best felt in the anterior axillary line, fifth intercostal space.arrow_forwardA stroke results froma. hemorrhage in the brain.b. a blockage of a blood vessel in the brain.c. a deficiency of tissue plasminogen activator.d. Both a and b are correct.arrow_forward
- The effects of the sympathetic and parasympathetic neurons on the heart can best be described as a. antagonistic b. identical c. cooperative d. adrenergicarrow_forwardThe heart’s internal pacemaker beats by: a. an internal implant that sends an electrical impulse through the heart b. the excitation of cardiac muscle cells at the sinoatrial node followed by the atrioventricular node c. the excitation of cardiac muscle cells at the atrioventricular node followed by the sinoatrial node d. the action of the sinusarrow_forwardAt point A, note that mean arterial blood pressure (MABP) is slightly lowered despite the large fall in cardiac output (CO). a. Why is CO decreased in response to hemorrhage? b. How is blood pressure maintained so well despite the fall in CO? c. What are the afferent receptors (sensors) responsible for this relatively well-maintained blood pressure at point A? d. What changes in stimuli for these receptors may be contributing to the response at point A? e. What efferent mechanisms mediate the increase in total peripheral resistance (TPR)?arrow_forward
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