The sinoatrial node sets the pace for the heart as a whole because sinoatrial node cells _____.   A are the only heart cells with an unstable resting membrane potential.   B are the only heart cells capable of initiating an action potential without the influx of positive ions through gap junction   C are located at the top of the heart in the interatrial septum   D have a faster rate of spontaneous depolarization than other pacemaker cells

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: Reductions in heart rate are normally caused by _____.   A sympathetic stimulation of the…

A: Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The…

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: Nodal (conductile) cells in the heart differ from other myocardiocytes (contractile cells) in that…

A: There are two major types of cardiac muscle cells present: myocardial contractile cells and…

Q: When the ventricles are no longer acting as a syncytium and can't pump blood, they are in ____.…

A: The conditions where the heart of a normal person is unable to function properly is called as heart…

Q: Parasympathetic stimulation of the sinoatrial node ______.   A is necessary; without it the heart…

A: Parasympathetic system of the body is responsible for the body's rest and digestion response when…

Q: Put these autorhythmic cells into the correct order for conveying electrical signals through a…

A: The sinoatrial node (SA node) acts as the pacemaker of the heart. By continuously creating new…

Q: Drugs that increase the heart rate have __________a effect.a. myogenicb. negative inotropicc.…

A: Answer is e.) positive chronotropic.

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: In pacemaker cells the movement of __________ into the cell through voltage-gated channels is…

A: The opening of channels that let positive ions flow into the cell can cause depolarization. Flow of…

Q: 1. The sympathetic nervous increases the heart rate by binding to F-type Na channels and increasing…

A: Introduction: The brief sequence of events in the membrane potential following excitation is…

Q: . ECG depicts the depolarization and repolarization processes of a cardiac cycle. In the ECG of a…

A: The electrocardiogram (ECG) is the total amount of the action potentials of millions of…

Q: Which statement about activation of heart muscle cells is TRUE?   A when a person is resting only a…

A: The electrical conduction system of the heart transmits signals generated usually by the sinoatrial…

Q: Between the second sound of one beat and the first sound of the next beat the _____.   A semilunar…

A: Heart sounds are generated by blood flowing in and out of the heart’s chambers through the valves as…

Q: The patient's ECG indicates that _____.     action potentials are passing from his atria into his…

A: Electrocardiogram or ECG is the record or graphical registration of electrical activities of the…

Q: During the depolarization phase of the pacemaker potential O a. Ca+2 permeability increases O b. Na+…

A:

Q: Which of these is an example of autoregulation? O The increased force response of the heart…

A: Autoregulation is a process that is well equipped in various biological systems within the body. It…

Q: Autorhythmic cells in the SA node intrinsically fire at a rate of - 90 action potentials per minute.…

A: While performing exercise, the cardiovascular apparatus performs two major tasks:- 1. Provides…

Q: ulmonary circulation differs from systemic circulation in that the______.   A blood pressure in…

A: Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood…

Q: a) Match the regions (Red, Green, Blue) with the functiontions. A. Contraction of the atria B.…

A: An ECG, which stands for electrocardiogram, is a diagnostic tool that records the electrical…

Q: Put the progression of the electrical excitation of the heart muscle in the right order Atrial…

A: Circulatory system is a part of body system which is involved in circulation of body fluids like…

Q: Ventricular relaxation immediately follows ________.a. atrial depolarizationb. ventricular…

A: The cardiac cycle is the duration of time that starts with atrial contraction and ends with…

Q: The patient's ECG indicates that _____.   A action potentials are passing from his atria into his…

A: Electrocardiography -- The process by which electrocardiogram is done defined as electrocardiography…

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: At the time point indicated on the ECG ____.   A blood would be flowing from the ventricles into…

A: An electrocardiogram can be defined as the type of test in which the heart's electrical activity is…

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: The atrioventricular valves open because ______.   A relaxation of the ventricles causes the…

A: Atrioventricular valves These are the valves which connect the atrium to the ventricles. There are…

Q: he blood pressure in the left ventricle during systole is ______ the blood pressure in the right…

A: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the…

Q: Cardiac action potentials have _________ duration than neuronal action potentials. A. a shorter…

A: Introduction Unlike the action potential in skeletal muscle cells, the cardiac nerve impulse isn't…

Q: The first heart sound is heard as the ECG records the end of the ______.   A P wave   B T-P…

A: An electrocardiogram (ECG or EKG) records the electrical signal from your heart to examine for…

Q: The cardiac plateau is mediated by ________ and it________ ventricular repolarization. Group of…

A: The cardiac plateau is a phase in the cardiac action potential. This phase is characterized by a…

Q: When the SA node doesn’t function properly, the AV node takes over pacing the heart and produces…

A: In the ecg of the individuals with junctional rhythm , P waves is not seen . This is because the…

Q: Isovolumetric contraction" is a phase in the cardiac cycle in which the volume of a particular heart…

A: Isovolumetric contraction" is a phase in the cardiac cycle in which the volume of a particular heart…

Q: The heart’s pacemaker is called the (complete term)_________. The pacemaker is composed of…

A: The cardiovascular system consists of the heart, the blood vessels, and most importantly, the blood.…

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: Let's review the electrical events that occur during a heartbeat. Match each phase of the ECG in the…

A: A. The atria depolarize ( P wave)B. The ventricles repolarize (T wave)C. (Diastolic interval; 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: What are funny channels in the heart? Pacemaker Na channels that open upon membrane depolarization O…

A: Pacemakers- Electrical impulses generated by the heart muscle that causes the heart to beat…

Q: What is occurring during isovolumetric relaxation during the cardiac cycle? O The ventricles are…

A: Cardiac cycle is defined as the sequence of coordinated events taking place in the heart during each…

Q: Once you have studied the wiggers diagram   Create your own outline of the steps with a brief…

A: Cardiac cycle:The cardiac cycle describes the human heart's activity from the start of one heartbeat…

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: The function of the right and left bundle branches is to _____.   A rapidly transmit action…

A: The atrioventricular bundle (bundle of His) is a continuation of the specialized tissue of the AV…