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

Q: Why do we need to prevent the decompensated state in patients with heart failure?

A: Decompensation is any functional decline of a system or structure which was operating earlier with…

Q: A drug that blocks the cardiac muscarinic receptor might be expected to: Increased heart rate…

A: Muscarinic acetylcholine receptors are G-protein coupled receptor that contains a…

Q: Parasympathetic stimulation decreases the heart rate by Decreasing permeability of SA node cells…

A: Parasympathetic postganglionic nerve fibers tend to be vagus nerve and are cholinergic in nature.…

Q: Describe the events leading up to contraction in a cardiac contractile cell. (Where does the…

A: Cardiac muscles are similar to skeletal muscles with a few differences:-a) Contraction is…

Q: Trace the biochemical electrical pathways that result in cardiac conduction

A: The collection of specialized cardiac myocytes located in the heart walls that send electrical…

Q: +20 A Membrane -20 potential (mV) -40 Threshold -60 -80 0.8 1.6 Time (s) AV node threshold…

A: The SA node and AV node in the heart are responsible for generating electrical impulses that are…

Q: Slow conduction in the atrioventricular node is associated with which of the following? Group of…

A: An atrioventricular nodal conduction delay can occur in a few disorders and may result in a delay in…

Q: Why is it necessary for cells of the cardiac atria and ventricles to contract in a coordinated…

A: Introduction :- Blood from the veins enters the two atria, which have thin walls. The heart's two…

Q: Discuss the regulation of cardiac output during exercise.

A: The cells are the primary unit of life. The cells form the tissues which collectively form an organ.…

Q: Explain your results using your knowledge of the cardiac cycle and of how the heart is regulated by…

A: ECG - it is graphical representation of activities of heart with help of chest leads that are placed…

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: In ECG, P and QRS waves represent what types of heart electrophysiological activity? Draw and speak.…

A: The circulatory patterns are of two types - open or closed. The open circulatory system is present…

Q: Why is it possible for acetylcholine to actually cause an increase in stroke volume, even though…

A: Acetylcholine is one of the most vital neurotransmitter in the human body, that is seen in both the…

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: ich of the following is an accurate descriptione d the subsequent (second) P wave (second cardi

A: Measuring rate and regularity of heartbeat, size, and shape by electrocardiograph, detect tiny…

Q: Compare and contrast the molecular events of the action potential in the pacemaker cells of the SA…

A: The action potential is a crucial physiological process that occurs in both pacemaker cells of the…

Q: What are the uses of cardiac troponins?

A: Troponins are a group of protein molecules that are found in skeletal and cardiac muscles. The…

Q: Cells in the body have the ability to undergo a transiet depolarization and repolarization. A. Plot…

A: The heart contracts and relaxes to pump blood throughout the body. The contraction is controlled by…

Q: 29. 30. State the significance of the longer action potential in a cardiac CONTRACTILE cell. State…

A: The myocardial contractile cells comprise the mass amount of the cells in the atria and ventricles.…

Q: Contrast action potentials in ventricular muscle cells with SA node action potentials.

A: A fast, sudden, propagating and transitory change of the muscle and nerve cell's resting membrane…

Q: If a heart lacked gap junctions, an organ-level contraction would occur.True/False

A: Cardiac muscles are the striated, involuntary, and branch muscles with a characteristic feature of…

Q: A drug that blocks the cardiac muscarinic receptor might be expected to: Increased heart rate…

A: Cardiac muscarinic antagonists are the agent that inhibits the function of the muscarinic receptors.…

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: Describe the anatomy of movement of the wave of cell depolarization throughout the heart during the…

A: The cardiac cycle:It is comprised of a whole relaxation and contraction of both the atrium and…

Q: What anatomic features slow the conduction rate of the action potential as it passes through the AV…

A: The conduction system is a collection of nodes and specialised conduction cells that initiate and…

Q: Discuss the role that vascular endothelial growth factor (VEGF) and its family of receptors play in…

A: The formation of blood vessels from the existing blood vessels is known as angiogenesis.…

Q: Find the Q10 values from 10-20°C and 20-30°C (given heart rates in bpm at 10°C = 5bpm, 20°C = 10bpm,…

A: The temperature coefficient (Q10) represents the factor by which the rate (R) of a reaction…

Q: Why is the cardiac action potential propagated more slowly in an AV node cell then in an atrial or…

A: Cardiac action potential  It refers to the short alteration in the voltage i.e. membrane potential…

Q: xamine one of the consequences of branching with a simple model shown in the figure. Assume that…

A: Assume that the resistance is R    So the resistance in the parallel 1Ro=1R+1R…

Q: Parasympathetic stimulation also increases the delay between atrial and ventricular contractions.…

A: In physiology, the parasympathetic nervous system is responsible for the stimulation of…

Q: If all plasma membrane Ca21 channels in contractile cardiac muscle cells were blocked with a drug,…

A: A heart muscle cell is similar to a large house with several doors and rooms. Ion channels are…

Q: Cardiovascular: How does the PSNS alter a pacemaker action potential? Give the mechanism.

A: The cells of the heart have a specialized function of initiating and conducting impulses for the…

Q: What mechanisms would be responsible for shortening of the ST segment TP interval T wave TP interval…

A: Introduction :- Electro-cardiogram (ECG) is a medical test that measures the electrical activity of…

Q: In a cardiac contractile cell what is the mechanism involved in the change in membrane potential?…

A: The cardiac contractile cell undergoes various changes in order to perform several activities and…

Q: Flecainide and propafenone are in Vaughan-Williams (antiarrhythmic) Class IC. What is the clinically…

A: Antiarrhythmics are drugs/medications that are prescribed to patients who are suffering from…

Q: Discuss the mechanism underlying AP generation by cardiac autorhythmic cells

A: Simply put, a cardiac arrhythmia is an abnormal heart rate and/or rhythm that is not biologically…

Q: Why is the Frank-Starling law of the heart important to the understanding of heart failure?

A: Frank starling law is a law that defines the relation between end diastolic volume and stroke…

Q: All of the following serum enzymes are elevated in myocardial infarction, except which of the…

A: MYOCARDIAL INFARTION A myocardial infarction (commonly called a heart attack) is a…

Q: Explain why part of the myocardium is nonfunctionalfollowing myocardial infarction.

A: The heart supplies blood to different parts of the body. Blood carries oxygen and nutrients to the…

Q: n the calculation of the heart rate using the number 300 method in the ECG, where did the number 300…

A: The cardiovascular system can be thought of as the transport system of the body. It consists of…