EP HUMAN BIOLOGY-MODIFIED MASTERING
8th Edition
ISBN: 9780134326436
Author: Johnson
Publisher: PEARSON CO
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 8, Problem 6AWK
Ventricular fibrillation is a potentially fatal condition where the cells of the heart are no longer coordinated in their contractions. Why is it important that contraction of the heart muscle occurs nearly all at once?
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 entry of calcium into a ventricular muscle cell helps to maintain depolarization of the membrane during the plateau phase of the action potential, but this calcium also performs what other function?
In a sheet of ventricular cardiac muscle tissue, we should be able to observe electricity spreading between adjacent muscle cells (TRUE or FALSE) and from Purkinje fibers to muscle cells (TRUE or FALSE) via electrical synapses that form between the cell membranes.
Chapter 8 Solutions
EP HUMAN BIOLOGY-MODIFIED MASTERING
Ch. 8 -
1. Who do you want to help you decide which...Ch. 8 - Do you think cost-effectiveness should be a part...Ch. 8 -
1. Why is it so important that the heart always...Ch. 8 - Compare and contrast the structures and functions...Ch. 8 - Prob. 3CRCh. 8 - Describe the function of the heart valves.Ch. 8 - Compare the functions of the pulmonary circuit and...Ch. 8 -
6. Describe the cardiac cycle of relaxation and...Ch. 8 - Describe the function of the SA and AV nodes as...Ch. 8 - Prob. 8CR
Ch. 8 - Prob. 9CRCh. 8 - Prob. 10CRCh. 8 -
1. _______ carry blood away from the heart and...Ch. 8 - Prob. 2TYCh. 8 - Which of the choices represents the order of...Ch. 8 - Prob. 4TYCh. 8 - Prob. 5TYCh. 8 - Prob. 6TYCh. 8 - Prob. 7TYCh. 8 - A pacemaker is used to correct: a. coronary artery...Ch. 8 - Prob. 9TYCh. 8 - Prob. 10TYCh. 8 - Prob. 11TYCh. 8 - Prob. 12TYCh. 8 - Prob. 13TYCh. 8 - Prob. 14TYCh. 8 - Prob. 15TYCh. 8 - Prob. 1AWKCh. 8 - When a coronary artery bypass graft (CABG) is...Ch. 8 - Soldiers have to stand in formation at full...Ch. 8 - Prob. 4AWKCh. 8 - Prob. 5AWKCh. 8 - Ventricular fibrillation is a potentially fatal...Ch. 8 - Prob. 7AWKCh. 8 - Last night, you and your roommate were sound...
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
- The ventricular walls of the human heart are more muscular as compared to the atrial walls. Why do cardiac muscles have a slow onset of contraction and prolonged contraction?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_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
- Roberto is a 78-year-old male who has recently been diagnosed with Class III Congestive Heart Failure (CHF). His physician told him that his left ventricle has become stiff and cannot relax. Although there is no current treatment that can “fix” Roberto’s condition, he is prescribed two medications: an ACE inhibitor and beta blockers. Briefly describe how beta-blockers will influence Roberto’s heart function, specifically the physiology of the ventricles.arrow_forwardRoberto is a 78-year-old male who has recently been diagnosed with Class III Congestive Heart Failure (CHF). His physician told him that his left ventricle has become stiff and cannot relax. Although there is no current treatment that can “fix” Roberto’s condition, he is prescribed two medications: an ACE inhibitor and beta blockers.Briefly describe how beta-blockers will influence Roberto’s heart function, specifically the physiology of the ventricles.arrow_forwardWhich of the following channels is responsible for generating the long plateau found in the action potentials of ventricular myocytes? a-slow Na+ channels b-slow Ca2+ channels c-leaky Ca2+ channels d-leaky Na+ channelsarrow_forward
- 1) 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_forwardWhat action potential of specialized heart cells know the function of each channel and the process?arrow_forwardThe 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 abovearrow_forward
- If 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_forwardIncreased contractility of the heart results in all of the following EXCEPT (A) increased stroke volume (B) increased force of contraction (C) increased end-systolic volume (D) increased venous returnarrow_forwardDiagram electrical conduction of the heart and discuss each component (SA node, AV node, etc). How does this dictate the fluidity of heart contraction? Why does the SA always start the conduction? What is the inherent rate of depolarization of the SA node (this means that if the nervous system was shut off what would resting bpm be)? If it is damaged what happens to the electrical conduction system?arrow_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
The Cardiovascular System: An Overview; Author: Strong Medicine;https://www.youtube.com/watch?v=Wu18mpI_62s;License: Standard youtube license