front 1 Cardiac muscle contraction: What opens voltage-gated fast Na+ channels in the sarcolemma? | back 1 depolarization |
front 2 Depolarization wave in T tubules causes the SR to release what? | back 2 Ca2+ |
front 3 Depolarization also opens slow _____ channels in the sarcolemma | back 3 Ca2+ |
front 4 In cardiac muscle contraction, there is a reversal of membrane potential from _____ mV to _____ mV | back 4 -90, +30 |
front 5 Repolarization results from inactivation of _____ channels and opening of voltage-gated ____ channels | back 5 Ca2+, K+ |
front 6 A network of noncontractile cells that initiate and distribute impulses to coordinate the depolarization and contraction of the heart | back 6 intrinsic cardiac conduction system |
front 7 What has unstable resting potentials (pacemaker potentials) due to open slow Na+ channels? | back 7 autorhythmic cells |
front 8 Sequence of excitation: What is present in the right atrium and generates impulses about 75 times/minute? | back 8 sinoatrial (SA) node (pacemaker) |
front 9 Sequence of excitation: what depolarizes faster than any other part of the myocardium? | back 9 SA node |
front 10 Sequence of excitation: What has smaller diameter fibers, fewer gap junctions, and delays impulses approximately 0.1 second? | back 10 atrioventricular (AV) node |
front 11 What depolarizes 50 times per minute in the absence of SA node input? | back 11 AV node |
front 12 Sequence of excitation: What is the only electrical connection between the atria and ventricles - divides into the left and right bundle branches? | back 12 atrioventricular (AV) bundle (bundle of His) |
front 13 What are the two pathways in the inter-ventricular septum that carry the impulses toward the apex of the heart? | back 13 right and left bundle branches |
front 14 What completes the pathway into the apex and ventricular walls? | back 14 purkinje fibers |
front 15 What depolarize only 30 times per minute in the absence of AV node output? | back 15 AV bundle and Purkinje fibers |
front 16 What are irregular heart rhythms? | back 16 arrhythmias |
front 17 What are rapid, irregular contractions, useless for pumping blood? | back 17 fibrillation |
front 18 A defective SA node may result in? | back 18 ectopic focus (abnormal pacemaker takes over) or if AV node takes over, a junctional rhythm (40-60 bpm) |
front 19 A defective AV node may result in? | back 19 partial or total heart block; few or no impulses from SA node reach the ventricle |
front 20 Intrinsic innvervation of the heart involves: | back 20 SA node generating impulse, which pauses at AV node; AV bundle connects atria to ventricles; bundle branches conduct impulses through interventricular septum; Purkinje fibers depolarize contractile cells of both ventricles |
front 21 Defects in the intrinsic conduction system may result in? | back 21 arrhythmias; uncoordinate atrial and ventricular contractions; fibrillations |
front 22 Extrinsic innervation of the heart: heartbeat is modified by the? | back 22 ANS |
front 23 Extrinsic innervation of heart: what center innervates SA and AV nodes, heart muscle, and coronary arteries through sympathetic neurons? | back 23 cardio-acceleratory center |
front 24 Extrinsic innervation of the heart: What center inhibits SA and AV nodes through parasympathetic fibers in vagus nerves? | back 24 cardio-inhibitory center |
front 25 What part of the ANS increases heart rate? | back 25 sympathetic |
front 26 Which part of the ANS slows heart rate? | back 26 parasympathetic |
front 27 What is a composite of all the action potentials generated by nodal and contractile cells at a given time? | back 27 electrocardiogram (EKG/ECG) |
front 28 What are the three waves of an EKG? | back 28 P wave, QRS complex, T wave |
front 29 Which EKG wave is the depolarization of the SA node? | back 29 P wave |
front 30 Which EKG wave is ventricular depolarization (activation of muscle fibers, contraction, blood pumped out)? | back 30 QRS complex |
front 31 Which EKG wave is ventricular repolarization (coming back to the original state, heart filled with blood)? | back 31 T wave |
front 32 When atrials contract, what do ventricles do? | back 32 relax |
front 33 What is low oxygen tension in the blood called? | back 33 hypoxemia |
front 34 What is low oxygen tension called? | back 34 hypoxia |
front 35 An EKG that shows no irregularites is called? | back 35 normal sinus rhythm |
front 36 An EKG that shows the SA node is nonfunctional, P waves are absent, and the heart is paced by the AV node at 40-60bpm is called? | back 36 junctional rhythm |
front 37 An EKG that shows some P waves are not conducted through the AV node, resulting in more P waves than QRS complexes (ratio 2 to 1) is called? | back 37 second-degree heart block |
front 38 Chaotic, grossly irregular EKG deflections are seen in acute heart attack and electrical shock. They are called? | back 38 ventricular fibrillation |
front 39 Hearts sounds are caused by what? | back 39 closing heart valves |
front 40 Which heart sound occurs as AV valves close, signifying the beginning of systole/ blood pumping away from the heart? | back 40 the first sound (lub) |
front 41 Which heart sound occurs when SL valves close at the beginning of ventricular diastole/blood going back into the heart? | back 41 the second sound (dup) |
front 42 What are abnormal heart sounds most often indicative of valve problems | back 42 heart murmurs |
front 43 Which heart sound is the closing of the mitral and tricuspid valves? | back 43 the first sound |
front 44 Which heart sound is the closure of semilunar walls of aorta and pulmonary trunk? | back 44 the second sound |
front 45 All events associated with blood flow through the heart during a complete heartbeat is called? | back 45 cardiac cycle |
front 46 What are the phases of the cardiac cycle? | back 46 ventriuclar filling, ventricular systole, isovolumetric relaxation |
front 47 What is the volume of blood in each ventricle at the end of ventricular diastole? | back 47 End diastolic volume (EDV) |
front 48 What is the volume of blood remaining in each ventricle after the end of systole? | back 48 End systolic volume (ESV) |
front 49 When does isovolumetric relaxation occur? | back 49 in early diastole |
front 50 What is a brief rise in aortic pressure that leads to the closure of the semilunar valves? | back 50 dicrotic notch |
front 51 What is the volume of blood pumped by each ventricle in one minute? | back 51 cardiac output (CO) |
front 52 How do you determine cardiac output? | back 52 heart rate (HR) x stroke volume (SV) |
front 53 Heart rate is? | back 53 number of beats per minute |
front 54 Stroke volume is ? | back 54 volume of blood pumped out by a ventricle with each beat |
front 55 What is the difference between resting and maximum cardiac output? | back 55 cardiac reserve |
front 56 What are the three main factors affecting stroke volume (SV)? | back 56 preload, contractibility, after load |
front 57 What is the degree of stretch cardiac muscle cells have before they contract ? | back 57 preload |
front 58 What is the Frank-Starling law of the heart? | back 58 the shorter the fiber, the shorter the power of contractibility |
front 59 What is the contractile strength at a given muscle length, independent of muscle stretch and EDV? | back 59 contractibility |
front 60 What is the pressure that must be overcome for ventricles to eject blood? | back 60 afterload |
front 61 Hypertension increases afterload, resulting in ? | back 61 increased ESV and reduced SV |
front 62 What hormones are involved with regulation of heart rate? | back 62 epinephrine and thyroxine |
front 63 What is an abnormally fast heart rate called? | back 63 tachycardia |
front 64 What is the bpm of tachycardia? | back 64 >100 bpm |
front 65 What is a heart rate slower than 60 bpm called? | back 65 bradycardia |
front 66 What is a progressive condition where the cardiac output is so low that blood circulation is inadequate to meet tissue needs? | back 66 congestive heart failure |
front 67 What is dilated cardiomyopathy? | back 67 muscle fibers elongate and stretch - heart enlarges/bursts |
front 68 Why do you see swelling/edema in the ankles of someone with congestive heart failure? | back 68 there is no venous return, blood pools to lower extremeties |
front 69 Blood travels into the right atrium via what? | back 69 superior and inferior vena cava |
front 70 Blood travels from the right atrium to the right ventricle via? | back 70 tricuspid valve |
front 71 Blood travels from the right ventricle through _____ to the lungs | back 71 pulmonary valve |
front 72 Blood travels from the left atrium to the left ventricle through what? | back 72 mitral valve |
front 73 What is the final valve blood travels though to get to the rest of the body? | back 73 the aortic valve (through the aorta) |