Biology: The Dynamic Science (MindTap Course List)
4th Edition
ISBN: 9781305389892
Author: Peter J. Russell, Paul E. Hertz, Beverly McMillan
Publisher: Cengage Learning
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Chapter 44, Problem 6TYK
Keeping the mammalian cardiac cycle balanced is/are:
a. an AV node between the right atria atrium and right ventricle, which induces a wave of contraction.
b. pacemaker cells, which compose the AV node and signal theSA node.
c. an insulating layer that isolates the SA node from the rightatrium.
d. ion channels in pacemaker cells, which close to depolarizetheir plasma membranes.
e. neurogenic stimuli from the nervous system.
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Chapter 44 Solutions
Biology: The Dynamic Science (MindTap Course List)
Ch. 44.1 - What are the three basic features of animal...Ch. 44.1 - Prob. 2SBCh. 44.1 - Prob. 3SBCh. 44.1 - Prob. 4SBCh. 44.2 - Outline the life cycle of an erythrocyte.Ch. 44.2 - Prob. 2SBCh. 44.2 - Prob. 3SBCh. 44.3 - Prob. 1SBCh. 44.3 - Prob. 2SBCh. 44.3 - How do neurogenic and myogenic hearts differ?
Ch. 44.3 - Describe the electrical events that occur during...Ch. 44.4 - Prob. 1SBCh. 44.4 - Prob. 2SBCh. 44.4 - Prob. 3SBCh. 44.5 - Prob. 1SBCh. 44.5 - Prob. 2SBCh. 44.5 - Prob. 3SBCh. 44.6 - Prob. 1SBCh. 44 - Prob. 1TYKCh. 44 - Prob. 2TYKCh. 44 - Prob. 3TYKCh. 44 - A characteristic of blood circulation through or...Ch. 44 - The heartbeat includes: a. the systole when the...Ch. 44 - Keeping the mammalian cardiac cycle balanced...Ch. 44 - Prob. 7TYKCh. 44 - Characteristics of veins and venules are: a. thick...Ch. 44 - Prob. 9TYKCh. 44 - Prob. 10TYKCh. 44 - Prob. 11TYKCh. 44 - Prob. 12TYKCh. 44 - Prob. 13TYKCh. 44 - Prob. 15TYKCh. 44 - Nifedipine is an antihypertension medication that...Ch. 44 - Prob. 2ITDCh. 44 - Nifedipine is an antihypertension medication that...
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- Which 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_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_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
- 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 downarrow_forwardWhich of the following has a correct sequence in cardiac cycle? A. Atrial depolarization → Ventricular diastole → T-wave B. Atrial diastole → Closing of tricuspid valve → Early ventricular diastole C. Ventricular repolarization → Ventricular contraction → P-wave D. Ventricular diastole → Opening of the pulmonic valve → Atrial systolearrow_forwardWhat is the consequence of the prolonged plateau of depolarization in ventricular myocytes? a-it causes ventricular myocytes to contract for a longer time, allowing the ventricles time to empty b-it gives additional time for the atria to contract, filling the ventricles more completely c-it causes repolarization to be delayed which slows heart rate d-it allows the ventricles a moment to rest before completing contractionarrow_forward
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