EBK HUMAN PHYSIOLOGY
8th Edition
ISBN: 9780134704227
Author: Silverthorn
Publisher: YUZU
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Textbook Question
Chapter 14.3, Problem 17CC
A new cardiac drug called ivabradine selectively blocks If channels in the heart. What effect would it have on heart rate and for what medical condition might it be used?
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A 65-year old man with heart failure is unable to climb a flight of stairs without experiencing dyspnea. After several years of therapy with carvedilol, captopril and furosemide, the therapeutic plan probably needs to change now. You empirically add digoxin to improve cardiac muscle contractility. Within 4 week he has a marked improvement in his symptoms. Which of the following best describes the main cellular action of digoxin that accounts for its ability to improve his cardiovascular function?
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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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- Patients with a history of heart failure often get this history from chronic hypertension. Chronic hypertension leads to a condition called hypertrophic heart disease, or hypertrophic cardiomyopathy. This means that the heart muscle gets bigger, allowing less room for it to fill with blood. If these patients take beta blockers, such as metoprolol, it will benefit them because the heart will not overwork and grow in size. However, if a patient has pulmonary edema, how could the beta blocker make this patient worse?arrow_forwardWhich of the following combinations would have OPPOSITE effects in changing heart rate? atropine and norepinephrine atropine and a cholinesterase inhibitor epinephrine and norepinephrine acetylcholine and a cholinesterase inhibitorarrow_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_forward
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- 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_forwardYou are testing a compound as cardioactive drug. You know the compound is an agonist of acetylcholine (ACh) at the relevant ACh receptor (AChR) on sinoatrial (SA) node cells. Briefly describe how the action of the drug likely would affect the electrical signal produced by the SA node cells. In respect of cardiac output, what would you expect to be the effect of this drug?arrow_forwardNitroglycerine is given as a therapy to patients suffering from angina pains. It gets converted into nitric oxide that results in the relaxation of smooth muscles surrounding the blood vessels. What will be the effect of this molecule on the stroke volume of the heart?arrow_forward
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