The movement of which two ions is responsible for maintaining the plateau phase of the action potential of contractile cardiac muscle cells? Select one: a. Ca2+ and Na+ b. Ca2+ and K+ c. Na+ and Cl- d. Na+ and K+ e. K+ and Cl-

Q: A patient has tachycardia. Would you recommend a drug that prolongsor shortens the plateau of…

A: Tachycardia is a condition that makes our heart beat more than 100 times per minute. There are three…

Q: Action potentials pass from one cardiac muscle cell to anothera. through gap junctions.b. by a…

A: The structures which provide adhesion and communication between cells are called intercellular…

Q: Which of the following lists the events of the cardiac cycle in thecorrect order?a. both atria…

A: Answer- Cardiac cycle is the process by which one total heartbeat is completed. It comprises of…

Q: Consider the equation cardiac output (CO) = stroke volume (SV) X heart rate Which of the following…

A: Afterload is the pressure the heart must work against to eject blood during systole. When…

Q: Which neurotransmitter/target receptor combinations would you expect to find in these areas of the…

A: Neurotransmitter and target receptor combinations in the areas of the heart are as follows: SA…

Q: Leaky Na+ channels in the cells of the SA Node do which of the following?   a-allow a slow…

A: d-allow a slow depolarization that eventually reaches the threshold for voltage-gated Ca2+ channels.

Q: The conductance of which ion results in phase 2 characteristics in a ventricular myocyte action…

A: The non-pacemaker cardiac action potentials include the atrial and ventricular myocytes and Purkinje…

Q: If leaky Na+ channels in the cells of the SA Node became more leaky (allowed Na+ through at a faster…

A: Generation of the action potential is a significant characteristic of the cells of the sinoatrial…

Q: Based on the concentration gradient of sodium, potassium, and calcium in cardiac myocytes, which of…

A: In a cell, the plasma membrane separates the internal environment (cytoplasm) from the external…

Q: Which of the following events occurs due to a reduced sympathetic stimulation of the heart? Question…

A: The objective of the question is to understand the effects of reduced sympathetic stimulation on the…

Q: Briefly describe the events of excitation-contraction coupling in cardiac muscle cells.

A: Cardiac muscles are also called myocardium, which is a type of muscle in the body that is…

Q: What event(s) occur during the QRS complex of an electrocardiogram? Select one: a. Repolarization…

A: The objective of the question is to identify the correct events that occur during the QRS complex of…

Q: Using the new cardiovascular drug Entresto, relate how the Cardiac action potential arriving at the…

A: Entresto is a brand-name prescription drug for treating specific forms of heart failure. Heart…

Q: Explain differences between action potentials of cardiac muscle cells and those in nodal cells of…

A: On the surface of the heart, muscle fibers are arranged to form a fused interconnected mass termed a…

Q: Which of these conditions occurs in the repolarization phase of an action potential in pacemaker…

A: When the change in the membrane potential occurs due to voltage decrease, then it is called…

Q: Why is the rate of cardiac muscle relaxation faster when a positive inotropic agent is present?

A: Inotropic agents refer to those substances that either increase or decrease the force of contraction…

Q: A heartbeat starts when autorhythmic cells in the 1 [ Select ] (located in the right atrium) create…

A: When blood is circulated through heart to the body, action potentials propagate through the heart,…

Q: You are supervising a student who is carrying out several experiments on an animal species that has…

A: Based on the description of the graph, the student has recorded the action potential and contraction…

Q: List the steps of a cardiac muscle cell CONTRACTION. Compare this to a skeletal muscle cell…

A: Muscle cell contraction is a complex physiological process that enables muscles to generate force…

Q: Explain why Purkinje fibers conduct action potentials morerapidly than other cardiac muscle cells

A: Purkinje fibers are components of the heart's advanced conduction system, which guarantees that an…

Q: What is the role of Ca2+ in the shape and duration of an action potential. (Cardiac muscle cell)

A: The duration of an action potential for cardiac muscle cell is between 200-250 milliseconds. There…

Q: raw a ventricular muscle cell action potential in the figure below. Briefly describe the changes in…

A: Similar to skeletal muscle, the resting membrane potential of ventricular cells, is around -90…

Q: We measured the stroke volume of the left ventricle. What was the average stroke volume of the rig|…

A: The term "cardiac output" (CO) is used to describe the amount of blood pumped up every minute by…

Q: Which ONE of the following statements is TRUE? OA Cardiac myocyte contraction results primarily from…

A: Given here are some statements . Following I will be discussing which among them is correct and…

Q: In which phase of the ventricular muscle action potential is the potassium permeability the highest?…

A: The phase of the ventricular muscle action potential in which the potassium permeability is the…

Q: People with paroxysmal atrial tachycardia (commonly called "palpitations") are sometimes given drugs…

A: Voltage gated calcium  channels allow the entry calcium into plasma membrane. Inside the calcium…

Q: Unlike skeletal muscle, cardiac muscle doesn’t undergo tetany. Explain how this is achieved and why…

A: Cardiac muscle or myocardium is the muscle that forms the heart tissue. These are striated and…

Q: Acetylcholine reacting with a muscarinic receptor on a cardiac myocyte causes chloride to flow, or…

A: In human anatomy, the pumping organ of the human body is known as the heart which is made up of…

Q: The carotid artery of an animal is partially constructed proximal to the carotid sinus during a…

A: Introduction:- The carotid arteries are a component of systemic circulation that transport blood to…

Q: A B 0 0 3 2 3 5 Time (msec) 5 Time (msec) 7 7 TO 10

A: Oscilloscope tracing in A and B showed a major difference in the rate of contractile activity.

Q: A drug is found to partially inactivate fast sodium channels. Mow would this drug change the action…

A: Given: To find a drug that partially inactivate fast sodium channels. How it change the action…

Q: Which is not true about early after depolarizations in ventricular cardiac muscle?     A.…

A: Action potential is generated in muscles due to the inward flow of positive ions. This depolarizes…

Q: The entry of calcium into a ventricular muscle cell helps to maintain depolarization of the membrane…

A: A well-working conduction system generates a depolarization wave, which causes the atria and…

Q: Describe the movement in ions in action potentials of these cells - pacemaker cell - cardiac…

A: Series of changes in various ion concentration such as calcium, sodium and potassium ions that…

Q: Keeps the cell tight together and prevent stretching of tight junction during contraction? Select…

A: Intercellular junction provide structural and functional link between the individual cell.…

Q: A. Calculate the output your pump should provide to the aortic arch. (in units of L/min) B. In…

A: To calculate the output the heart should provide to the aortic arch, we need to determine the stroke…

Q: Epinephrine is the chief neurotransmitter of the sympathetic nervous system. What effect would you…

A: A neurotransmitter is a chemical substance produced and released by neurons (nerve cells) to…

Q: An action potential reaches a cardiac contractile cell, which fires, but then does not propagate the…

A: The heart muscle (also called the heart muscle or myocardium) is one of three types of spinal muscle…

Q: blocked the pore/channel in the L-type calcium channel in cardiac muscle cells. The drug had no…

A: L type calcium channels causes simultaneous excitation contraction cycling  of cardiac muscles.…