Human Physiology
15th Edition
ISBN: 9781259864629
Author: Fox, Stuart Ira
Publisher: Mcgraw-hill Education,
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 13, Problem 35RA
Summary Introduction
Â
To review:
Â
The mechanism of drugs which blocks the voltage gated Ca2+ (calcium ions) channels.
Introduction:
Paroxysmal arterial tachycardia is the period of irregular heartbeat that starts in the atria and the heart beats at a faster pace. Tachycardia is described when the cardiac rate is faster than 100 beats per minute.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Describe why a doctor would give a patient that is diagnosed with acute myocardial infarction the treatment of tissue plasminogen activator(tPA)? What will it do?
I need to calculate the approximate heart rate based on the given ECG results, but I can't get how to determine the length of time between two consecutive R waves. What I see, it's one second between the two highest waves (I suppose they are R waves). But it means the heart rate should be 60 beats per minute, but there is no option for this answer. Teach me how to determine correctly the length of time between two consecutive R waves.
Why is the cardiac action potential propagated more slowly in an AV node cell then in an atrial or ventricular myocyte? How can be AV conduction affected by hypokalemia? Briefly explain the mechanism by which the most popular beta-blocker metoprolol would affect cardiac muscle contractility and blood flow. How it affects heart rate and conduction?
Chapter 13 Solutions
Human Physiology
Ch. 13 - State the components of the circulatory system...Ch. 13 - Prob. 1bCPCh. 13 - Prob. 2CPCh. 13 - Prob. 3CPCh. 13 - Describe how the rate of erythropoiesis is...Ch. 13 - Prob. 5aCPCh. 13 - Prob. 5bCPCh. 13 - Using a flow diagram (arrows), describe the...Ch. 13 - Use a flow diagram to describe the systemic...Ch. 13 - List the AV valves and the valves of the pulmonary...
Ch. 13 - Discuss how defective valves affect blood flow...Ch. 13 - Prob. 7bCPCh. 13 - Prob. 8aCPCh. 13 - Prob. 8bCPCh. 13 - Draw a figure to illustrate the pressure...Ch. 13 - Prob. 10aCPCh. 13 - Using a line diagram, illustrate a myocardial...Ch. 13 - Draw an ECG and label the waves. Indicate the...Ch. 13 - Draw a figure that shows the relationship between...Ch. 13 - Prob. 11cCPCh. 13 - Prob. 12aCPCh. 13 - Prob. 12bCPCh. 13 - Explain the functions of capillaries and describe...Ch. 13 - Prob. 14CPCh. 13 - Prob. 15CPCh. 13 - Identify normal and pathological causes of...Ch. 13 - Prob. 16bCPCh. 13 - Prob. 17aCPCh. 13 - Explain how the lymphatic system and the...Ch. 13 - Prob. 18CPCh. 13 - Prob. 1RACh. 13 - All arteries in the body contain oxygen-rich blood...Ch. 13 - The "lub," or first heart sound, is produced by...Ch. 13 - The first heart sound is produced at
Ch. 13 - Changes in the cardiac rate primarily reflect...Ch. 13 - Prob. 6RACh. 13 - Prob. 7RACh. 13 - The cells that normally have the fastest rate of...Ch. 13 - Which of these statements is true? a. The heart...Ch. 13 - Prob. 10RACh. 13 - Prob. 11RACh. 13 - Prob. 12RACh. 13 - Prob. 13RACh. 13 - Prob. 14RACh. 13 - Prob. 15RACh. 13 - During the phase of isovolumetric relaxation of...Ch. 13 - Peristaltic waves of contraction move fluid within...Ch. 13 - Describe how the pacemaker cells produce a...Ch. 13 - What characteristic of the SA node distinguishes...Ch. 13 - Compare the duration of the heart's contraction...Ch. 13 - Step by step, describe the pressure changes that...Ch. 13 - Can a detective valve be detected by an ECG? Can a...Ch. 13 - Describe the causes of the P, QRS, and T waves of...Ch. 13 - The lungs are the only organs that receive the...Ch. 13 - Prob. 25RACh. 13 - Prob. 26RACh. 13 - Prob. 27RACh. 13 - Prob. 28RACh. 13 - Prob. 29RACh. 13 - Prob. 30RACh. 13 - Prob. 31RACh. 13 - Prob. 32RACh. 13 - Prob. 33RACh. 13 - Prob. 34RACh. 13 - Prob. 35RACh. 13 - Prob. 36RACh. 13 - Prob. 37RACh. 13 - Prob. 38RACh. 13 - Prob. 39RACh. 13 - Prob. 40RACh. 13 - Prob. 41RACh. 13 - Prob. 42RA
Knowledge Booster
Learn more about
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
- We 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_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_forwardPeople with paroxysmal atrial tachycardia (commonly called "palpitations") are sometimes given drugs that block voltage-gated Ca++ channels in the plasma membrane of myocardial cells. in order to slow the heartbeat. By what mechanism could these drugs help?arrow_forward
- Explain the association between atherosclerosis and ischemic heart disease. Imagine that you were the Surgeon General of the United States. What types of programs would you advocate to decrease heart disease? Do you think that as a society we should invest resources into the development of stemcell therapies for more effective treatment of myocardial infarction?arrow_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_forwardDescribe the mechanical events of the cardiac cycle. (use terms like atrial systole, atrial diastole, ventricular diastole, ventricular systole, isovolumic ventricular contraction, isovolumic ventricular relaxation, ventricular ejection, period of rapid filling)arrow_forward
- Consider 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_forwardIf all plasma membrane Ca21 channels in contractile cardiac muscle cells were blocked with a drug, what would happen to the muscle’s action potentials and contraction?arrow_forwardSelect TRUE or FALSE to best describe the statements below, relating the events of the cardiac cycle. Keep in mind that these events may be chemical, electrical and mechanical. atrial pressure is greater than ventricular pressure while semilunar valves are оpen ventricular pressure is greater than atrial pressure when the atrioventricular valves are closed atrioventricular valves are open during ventricular emptying the end diastolic volume of the ventricles is reached before ventricles contract 1 ventricular filling occurs before depolarization of the atria 1 atrioventricular valves and 1. TRUE 1 semilunar valves are closed at the beginning of ventricular systole 2. FALSE end systolic volume increases when more blood empties from the ventricles the greatest pressure is reached in the ventricles while they are emptying the right atrium depolarizes before the left atrium ventricular depolarization occurs during the T-wave semilunar valves are open during ventricular filling ventricular…arrow_forward
- What are the difference between contractile cells of the heart and electrical cells responsible for generation and conduction of impulses. Why is the cardiac action potential propagated more slowly in an AV node cell than in an atrial or ventricular myocyte? How are the channels and ions that are responsible for depolarization and repolarization work? How can be AV conduction affected by hypokalemia?arrow_forwardThe events of the cardiac cycle cause cyclical changes in left ventricular pressure and volume over time. Another way to represent these events is with a pressure-volume loop, as shown below. Drag the labels from the left into the appropriate boxes on the pressure- volume loop to demonstrate your understanding of the cardiac cycle. Aortic valve closure AV valve opening Systolic pressure Isovolumetric relaxation Isovolumetric contraction 120 Diastolic pressure Ventricular filling 80 End-diastolic volume Ventricular ejection 40 AV valve closure End-systolic volume Aortic valve opening 60 120 LV volume (mL) O McGraw-Hill Education Reset LV pressure (mm Hg)arrow_forward1)An increase in total peripheral resistance, all else remaining the same, will cause an increase in mean arterial pressure.True/False 2) We care about mean arterial pressure specifically because we care about having an appropriate rate of blood flow through capillaries. True/False 3) A person's L-type channels are mutated so that they do not inactivate. How would this affect the time duration of a cardiac action potential? Group of answer choices a)Increase b)No change c)Decrease 4) A person' L-type channels are mutated so that they do not inactivate. How would this affect the time duration of a cardiac muscle cell contraction? Group of answer choices a)Increase b)No change c)Decreasearrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...
Biology
ISBN:9781285866932
Author:Lauralee Sherwood
Publisher:Cengage Learning
12 Organ Systems | Roles & functions | Easy science lesson; Author: Learn Easy Science;https://www.youtube.com/watch?v=cQIU0yJ8RBg;License: Standard youtube license