EBK HUMAN PHYSIOLOGY
8th Edition
ISBN: 9780134704227
Author: Silverthorn
Publisher: YUZU
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Textbook Question
Chapter 14.3, Problem 12CC
A drug that blocks all Ca2+ channels in the myocardial contractile cell membrane is placed in the solution around the cell. What happens to the force of contraction in that cell?
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OE) All of the above
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Chapter 14 Solutions
EBK HUMAN PHYSIOLOGY
Ch. 14.1 - A cardiovascular system has what three major...Ch. 14.1 - What is the difference between (a) the pulmonary...Ch. 14.2 - Which is more important for determining flow...Ch. 14.2 - The two identical tubes below have the pressures...Ch. 14.2 - All four tubes below have the same driving...Ch. 14.2 - Two canals in Amsterdam are identical in size, but...Ch. 14.3 - What prevents electrical signals from passing...Ch. 14.3 - Prob. 8CCCh. 14.3 - Prob. 9CCCh. 14.3 - Compare the receptors and channels involved in...
Ch. 14.3 - If a myocardial contractile cell is placed in...Ch. 14.3 - A drug that blocks all Ca2+ channels in the...Ch. 14.3 - Which ions moving in what directions cause the...Ch. 14.3 - At the molecular level, what is happening during...Ch. 14.3 - Lidocaine is a molecule that blocks the action of...Ch. 14.3 - What does increasing K+ permeability do to the...Ch. 14.3 - A new cardiac drug called ivabradine selectively...Ch. 14.3 - Do you think that the Ca2+ channels in...Ch. 14.3 - What happens to the action potential of a...Ch. 14.3 - In an experiment, the vagus nerve, which carries...Ch. 14.4 - Name two functions of the AV node. What is the...Ch. 14.4 - Prob. 22CCCh. 14.4 - Occasionally an ectopic pacemaker {ktopos, out of...Ch. 14.4 - Prob. 24CCCh. 14.4 - Which chamberatrium or ventriclehas higher...Ch. 14.4 - Prob. 26CCCh. 14.4 - Prob. 27CCCh. 14.4 - Prob. 28CCCh. 14.4 - Prob. 29CCCh. 14.4 - Why does ventricular pressure shoot up suddenly at...Ch. 14.4 - Prob. 31CCCh. 14.4 - Prob. 32CCCh. 14.4 - A persons aortic valve opening has become...Ch. 14 - What contributions to understanding the...Ch. 14 - List three functions of the cardiovascular system.Ch. 14 - Prob. 3RQCh. 14 - Prob. 4RQCh. 14 - Prob. 5RQCh. 14 - Prob. 6RQCh. 14 - Prob. 7RQCh. 14 - Distinguish between the two members of each of the...Ch. 14 - Prob. 9RQCh. 14 - Prob. 10RQCh. 14 - What is the proper term for each of the following?...Ch. 14 - List the events of the cardiac cycle in sequence,...Ch. 14 - Prob. 13RQCh. 14 - Compare and contrast the structure of a cardiac...Ch. 14 - Prob. 15RQCh. 14 - Correlate the waves of an ECG with mechanical...Ch. 14 - Prob. 17RQCh. 14 - List and briefly explain four types of information...Ch. 14 - Define inotropic effect. Name two drugs that have...Ch. 14 - Prob. 20RQCh. 14 - Police Captain Jeffers has suffered a myocardial...Ch. 14 - Prob. 22RQCh. 14 - Prob. 23RQCh. 14 - Police Captain Jeffers in question 21 has an...Ch. 14 - Prob. 25RQCh. 14 - Prob. 26RQCh. 14 - Prob. 27RQCh. 14 - A person has a total blood volume of 5 L. Of this...
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- The pressure in the aorta changes throughout the cardiac cycle. During systole, as the heart contracts, the outflux of blood into the aorta causes an increase in pressure, whereas during diastole the pressure decreases as the heart relaxes. A simple model for the aortic pressure waveform is given by the Windkessel effect described by the image below. In this model, the heart is considered a pressure generating pump which is directly connected to an elastic compartment (the aorta), which in turn is connected to a rigid set of peripheral vessels (the hose of the firefighter). 5 Pump Heart Air Windkessel Elastic arteries In order to find the aortic pressure waveform from the Windkessel model, a mass balance formulation around the aorta must be formulated. Coming into the aorta from the heart we have the flowrate Q(t). According to conservation of mass, this inflow rate Q(t) must be equal to the outflow rate into the peripheral vessels and the change in volume of the aorta. To find these…arrow_forwardWe analyzed the difference between the action potential of a cardiac contractile cell and an action potential in a neuron. Describe the physiological mechanisms behind the primary difference in the shape of these two action potentials. Why is this feature important to the normal workings of the heart?arrow_forwardConsider the ventricular cardiomyocyte action potential shown below: a) Which phase of the cardiac myocyte action potential would be most significantly affected by the L-type calcium channel blocker nifedipine? b) Draw the predicted effects of nifedipine on the cardiac myocyte action potential.arrow_forward
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- In a patient given a cardiac glycoside, important effects of the drug on the heart include which of the following? a) Increased force of contraction. b)Decreased atrioventricular conduction velocity c)Decreased ejection time d)Increased ectopic automaticityAll of the abovearrow_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_forward1) A drug was applied to a person that blocked the pore/channel in the L-type calcium channel in cardiac muscle cells. The drug had no other effects. True/false: Cross-bridge cycling and tension production would occur normally in drug-treated fibers. 2) The plateau phase of a cardiac action potential is an absolute refractory period.True/false 3) If a heart lacked gap junctions, an organ-level contraction would occur.True/false 4) During a pacemaker potential, what is caused in neighboring muscle fibers when threshold potential is reached. Group of answer choices a)cross-bridge cycling b)Receptor potential c)An action potential d)A graded potentialarrow_forward
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