Human Physiology: An Integrated Approach (8th Edition)
8th Edition
ISBN: 9780134605197
Author: Dee Unglaub Silverthorn
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 14.4, Problem 23CC
Occasionally an ectopic pacemaker {θktopos, out of place} develops in part of the heart’s conducting system. What happens to heart rate if an ectopic atrial pacemaker depolarizes at a rate of 120 times per minute?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these 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?
The rapid depolarization phase of heart pacemaker cells is caused by which of the
following?
movement of Na+ through funny channels
movement of Ca++ through L-type channels
movement of Na+ and Ca++ through funny channels
movement of K+ through funny channels
all of the above
Occasionally an ectopic pacemaker will develop in part of the conducting system of the heart. What happens to heart rate if an ectopic pacemaker depolarizes at a rate of 120 times per minute?
Chapter 14 Solutions
Human Physiology: An Integrated Approach (8th Edition)
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...
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
- In the given table, three of the anatomical and physiological terms are similar or related; one does not belong with the other three. Choose the term that does NOT belong in each of the following groups. A B C D 1 Pulmonary Trunk Vena Cava Right Side of the Heart Left Side of the Heart 2 QRS Wave T Wave P Wave Electrical Activity of the Ventricles 3 AV Valves Closed AV Valves Opened Ventricular Systole Semilunar Valves Open 4 Tricuspid Valve Mitral Valve Bicuspid Valve Left AV Valve 5 Pulmonary Valve Umbilical Artery Pulmonary Vein Superior Vena Cavaarrow_forwardDraw these five graphs on the same set of axes: atrial autorhythmic cell action potential atrial cardiac contractile cell action potential ventricular autorhythmic cell action potential ventricular cardiac contractile cell action potential ventricular myocardial muscle tensionarrow_forwardIf SA node (=natural pacemaker) firing rate is 100 potentials per minute, but resting heart rate of a person is 75bpm, what accounts for the difference? Iarrow_forward
- In the figure below on the left, label the P, QRS and T waves. Describe what is happening in the heart in the P wave: Relate the P wave to the cardiac cycle:o Is the heart in systole or diastole?o Is the pressure high or low?o Where is blood flowing? Which valves are open? closed? o Which muscle fibers are contracting, if any?arrow_forwardIf leaky Na+ channels in the cells of the SA Node became more leaky (allowed Na+ through at a faster rate), what would happen to the heart rate? a-it wouldn't change b-it would decrease c-it would increasearrow_forwardThe 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_forward
- Why is ventricular fibrillation such a serious arrhythmia?arrow_forwardBelow are drawings of three different action potentials. Two of these occur in the heart, and one occurs in skeletal muscle. Which one comes from a contractile cardiac muscle cell? A skeletal muscle cell? A cardiac pacemaker cell? For each one, state which ion is responsible for the depolarization phase and which ion is responsible for the repolarization phase.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning
Comprehensive Medical Assisting: Administrative a...NursingISBN:9781305964792Author:Wilburta Q. Lindh, Carol D. Tamparo, Barbara M. Dahl, Julie Morris, Cindy CorreaPublisher:Cengage Learning- Basic Clinical Lab Competencies for Respiratory C...NursingISBN:9781285244662Author:WhitePublisher:Cengage
Medical Terminology for Health Professions, Spira...Health & NutritionISBN:9781305634350Author:Ann Ehrlich, Carol L. Schroeder, Laura Ehrlich, Katrina A. SchroederPublisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...
Biology
ISBN:9781285866932
Author:Lauralee Sherwood
Publisher:Cengage Learning
Comprehensive Medical Assisting: Administrative a...
Nursing
ISBN:9781305964792
Author:Wilburta Q. Lindh, Carol D. Tamparo, Barbara M. Dahl, Julie Morris, Cindy Correa
Publisher:Cengage Learning
Basic Clinical Lab Competencies for Respiratory C...
Nursing
ISBN:9781285244662
Author:White
Publisher:Cengage
Medical Terminology for Health Professions, Spira...
Health & Nutrition
ISBN:9781305634350
Author:Ann Ehrlich, Carol L. Schroeder, Laura Ehrlich, Katrina A. Schroeder
Publisher:Cengage Learning
The Cardiovascular System: An Overview; Author: Strong Medicine;https://www.youtube.com/watch?v=Wu18mpI_62s;License: Standard youtube license