PHYSIOLOGY 452 552 CARDIO PHYSIOLOGY EXAMINATION VERSION 1 Thursday May 8th 2014 INSTRUCTIONS This examination consists of 32 questions 8 pages including this cover page Please check that your copy has all pages Print your name and 8 digit UB person number on the answer sheet Mark your answers carefully on the answer sheet with a 2 pencil If you erase do so completely You may keep the examination Results and answer keys will be posted as soon as possible on UBLearns WE DO NOT ANSWER QUESTIONS DURING THE EXAMINATION We need to see your UB ID card If you have forgotten your card please bring it to the Department Office 124 Sherman within 24 hours TO PREVENT CHEATING ON EXAMS Keep your answer sheet covered Please inform one of the instructors if you suspect someone is cheating your comments will be kept confidential Turn off all cell phones BE SURE TO FILL IN TEST VERSION NUMBER ON THE SCANTRON On side two of your answer sheet Scantron there is a Grade or Education box below the Identification box where you add your student person number In this box fill in the appropriate version number If you do not add your exam version you will receive a zero 0 for this exam If you fill in the WRONG number you will be scored for the number you fill in If you fill in the wrong number it cannot be changed after you turn in your exam BE ON TIME No one will be allowed to start the exam after 9 50 am 1 1 Which of the following is part of the specialized conduction system A B C D E Papillary muscle Epicardium Purkinje fiber Apex None of the above 2 Which portion of the heart contracts first A B C D E Right atrium Atrial ventricular node Ventricle Left ventricle Node of Ranvier 3 A Sarcomere is A B C D the basic secretory subunit of heart muscle a large multi nucleated array of myofibrils essentially one large fused cell equivalent to the cell membrane which covers the entire fiber a specialized form of the endoplasmic reticulum adapted for calcium uptake and release E None of the above 4 Tetanic contraction following rapid neuronal stimulation occurs in which region of cardiac muscle A B C D E Atrium Sino atrial node Bundle of His All of the above None of the above 5 In heart muscle the maximum force developed is sensitive to the initial myocardial fiber length Which is true over most of the physiological range A Increased initial myocardial fiber length results in increased maximum developed force B Decreased initial myocardial fiber length results in increased maximum developed force C Initial myocardial fiber length has an inverse square law relationship to maximum developed force D Both A and C E B and C 2 6 The muscle tissue which has the largest propagation delay in the specialized conduction system is A B C D E the bundle of His the Purkinje fiber the Atrial Ventricular node the endocardium the septum 7 In cardiac muscle which statement about the intracellular Chloride concentration is false A B C D E Cl is lower on the intracellular side than the extracellular side Cl is at its electrochemical equilibrium Cl is regulated in part by coupled transport Ecl is positive to the reversal potential for potassium None of the above are false 8 The Cardiac Sarcoplasmic Reticulum is A B C D E the basic secretory subunit in skeletal muscle equivalent to the cell membrane which covers the entire fiber a highly organized array of contractile units a specialized intracellular structure that stores calcium None of the above 9 Skeletal and cardiac muscle thick filaments contain A B C D E Actin Troponin Tropomyosin Myosin All of the above 10 Thin filaments do not contain A B C D E Actin Troponin Tropomyosin Myosin None of the above 3 11 Cardiac muscle relaxation is controlled by A B C D E Intracellular potassium Intracellular calcium Myosin kinase IP3 inositol tris phosphate channels All of the above 12 Skeletal muscle contraction is influenced by A B C D E frequency of stimulation calcium release from the Sarcoplasmic Reticulum dihydropyridine receptors ryanodine receptors All of the above 13 Smooth muscle contraction involves A B C D E T tubules Sarcomeres Myosin kinase All of the above None of the above 14 Which of the following is not true about the resting cardiac membrane potential A B C D E The membrane resting potential is equal to the Nernst potential for potassium The membrane resting potential has a low sodium conductance Balanced current flow gives rise to the resting membrane potential Pumps and exchangers maintain the background electrical gradients The Nernst potential for sodium is not equal to the resting membrane potential 15 Which of the following is not true about action potentials A B C D E Action potentials arise from current flow across membranes Current is carried by charged ions in solution Action potentials fire in an all or none fashion Rapid Potassium channel activation initiates the action potential Chloride is at lower concentrations on the intracellular side of the membrane 4 16 During the early phases of a normal action potential of fast myocardium e g ventricle which is not true of the sodium channel A B C D E It has multiple gates It is refractory The fastest gates open the channel in response to a depolarization A slower gate shuts the open channel down in response to sustained depolarization It fires transiently 17 What is not true of most potassium channel alpha subunits A B C D E They are formed from four linked domains Tetramer forms a functional channel It is selective for potassium over other cations It is selective for potassium over anions It opens and closes randomly 18 The voltage sensor of six membrane spanning segment potassium channels A B C D E is formed by positive charged amino acid side chains on S6 is formed by a gate on the intracellular side of S4 contains positively charged potassium ions is formed by negative charges on S4 None of the above 19 Which properties of the electrocardiogram are not true A B C D E The P Wave corresponds to excitation of the Sino Atrial Node The QRS complex corresponds the depolarization of the ventricle The T wave corresponds to the repolarization of the ventricle The electrocardiogram gives a measure of the timing of events in the heart All are true 20 Voltage Clamp is A B C D E a method for measuring electroneutral currents in cells a method for resuscitating victims of an arrhythmia a method for measuring the electrocardiogram a method for measuring contractility None of the above 5 21 Which is not true of the sino atrial