Ventricular Contractility increases in response to circulating Epinephrine.  What factor is responsible for this increase in the force of the contraction?

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: 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: Explain the electrical events that generate each portion of the electrocardiogram.  How do they…

A: Heart conduction is necessary for blood regulation. As these conduction activities are related to…

Q: What initiates action potentials in cardiac muscle?

A: Generation of action potential activates the neuron during the generation of stimuli. It is studied…

Q: What would be the drawback of cardiac contractions being the same duration as skeletal muscle…

A: Cardiac muscles are specialized in the way that long action potentials are generated in the cardiac…

Q: You are testing a compound as cardioactive drug. You know the compound is an agonist of…

A: The sinoatrial (SA) node is known as the natural pacemaker of the heart, responsible for generating…

Q: Explain the term isovolumetric ventricular contraction?

A: The cardiac cycle in animals is the result of the atrial and ventricular contraction and relaxation…

Q: If a myocardial infarction damaged the left bundle branch, how would this affect the spread of the…

A: Myocardial infarction is a condition when blood flow is abrupt to the heart. It either decreases or…

Q: Describe the electrical event in the heart that occurs during each of the following: (a) the QRS…

A: Heart is a muscular organ which is responsible for pumping the fluid connective tissue called blood…

Q: the difference between the action potential of a cardiac contractile cell and an action potential in…

A: Cardiac action potentials in the heart differ considerably from action potentials found in neural…

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: Draw a ventricular muscle cell action potential.

A: The heart is a four chambered structure that is responsible for pumping the blood into the arteries…

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: Why is ventricular fibrillation such a serious arrhythmia?

A: The term ‘arrhythmia refers to an abnormal condition of the heart in which the rate and frequency at…

Q: Why do the coronary arteries carry a greater blood flow during ventricular relaxation than they do…

A: The cardiovascular system is one of the organ systems of the body and its function is to circulate…

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: During which two periods of the cardiac cycle do the heart muscle fibers exhibit isometric…

A: The cardiac cycle explains the cardiac event that occurs during the contraction and relaxation of…

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: What are the two functional importances of the intercalated discs of cardiac muscle?

A: The intercalated discs are a specific feature of cardiac muscle fiber where it supports synchronized…

Q: Why is the plateau phase so critical to cardiac musclefunction?

A: The heart is a hollow muscular organ. It pumps the blood through the blood vessels of the…

Q: What effect would stimulating the acetylcholine receptors of the heart have on cardiac output?

A: The heart is the primary muscular organ of the cardiovascular system that is responsible for pumping…

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: Using information provided in the text, calculate the power generatec by the right ventricle during…

A: It has been given that the blood flow at rest is 5 liter/min. It implies that the flow of the blood…

Q: How does the cardiac contractile refractory period differ from a typical skeletal muscle refractory…

A: The muscle fibers are multi-nucleated (exclusively in the case of skeletal muscle fibers),…

Q: Which part of the intrinsic conduction system directly excites ventricular myocardial cells? In…

A: The intrinsic conduction system sets the basic rhythm of the heart beat by either spontaneously…

Q: Which of the following channels is responsible for generating the long plateau found in the action…

A: Answer :- Option (B) is correct.   - slow Ca2+ channels.

Q: By what mechanism does the autonomic nervous system impact the contractions of cardiac muscle?

A: A complex network of specialised cells called neurons make up the nervous system, which transmits…

Q: Does the right ventricular stroke work index (RVSWI) measure the amount of work required by the…

A: Right ventricle is one of the four chambers of the heart which receives deoxygenated blood from the…

Q: What is the consequence of the prolonged plateau of depolarization in ventricular myocytes?   a-it…

A: the consequence of the prolonged plateau of depolarization in ventricular myocytes.