Physiology of the Heart
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61 terms
Terms | Definitions |
|---|---|
 The cardiovascular system is essentially a transport system. What does it transport besides blood? | substrates for energy production, immunocompetent cells, heat |
| The left ventricle is a part of the _______ circulation. | systemic |
| The fibers of the median layer of cardiac muscle run in which direction? | diagonally |
| What is true of diastole? | an increased heart rate shortens diastole more than systole |
| What causes the valves of the heart to open and close, allowing the blood to pass from chamber to chamber ? | changes in pressure between the chambers |
| What is isovolumetric contraction? | contraction of the ventricle with increased pressure, but without change in volume |
| What is enddiastolic volume | the maximum volume of the entire cycle |
| What is stroke volume? | difference between enddiastolic volume and endsystolic volume |
| What generates the initial action potential in a healthy heart? | SA node |
| The term inotropic refers to what type of effect? | change in force of contraction |
| What is the correct order of receipt of action potentials in the heart? | SA node, AV node, bundle branches, Purkinje fibers |
| If the SA node fails, the AV node takes over heart rate determination. How do the rates of these two node compare? | AV node is slower |
| What is the purpose of the AV node on depolarization? | frequency filter |
| In regards to the heart, what does the parasympathetic nervous system not innervate? | left and right ventricles |
| What is the term for a change in speed of conduction? | dromotropic |
| The SA node is also known as what? | the pacemaker of the heart |
| Increased contractility results in what / | increased stroke volume |
| An electrocardiogram is a measure of what? | electrical events in the heart |
| When a lead is placed on each arm and the left leg, what is created? | Einthoven triangle |
| What is meant by Lead II? | the area between electrodes 1 and 3 |
| What is the signal difference between the Goldberger method versus the Einthoven method? | Goldberger is stronger |
| How is the placement of electrode different in Wilson's method? | it uses electrodes on the chest |
| What does the QRS interval measure? | ventricular depolarization |
| What paper speed gives a better idea of random rhythmic events? | low speed |
| What is the major difference between a vectorcardiogram and an electrocardiogram? | vectorcardiogram shows all 3 leads, while ECG shows just one |
| What grades of heart murmurs are defined by the 'palpable thrill'? | 5 and 6 |
| How are murmurs generated? | turbulent blood flow |
| what is the main limitation of the vectorcardiogram? | cannot determine the duration of time when the heart is either completely repolarized or depolarized |
| What is a compensator pause? | time between ventricular extrasystole and supraventricular extrasystole |
| What is the major difference between fibrillation and flutter? | fibrillation is faster |
| What is a myocardial infarction? | blockage of the coronary arteries |
| What is the minimum cardia output? | minimum amount of blood the tissues need to maintain their metabolism |
| What are heart sounds? | sounds created by movement of blood and vibrations of the muscles and valves |
| What creates a machinery murmur? | combination of stenotic and insufficient valves; PDA |
| What is the largest loop in a vectorcardiogram? | R wave |
| What is a characteristic of a ventricular pacemaker? | no P waves |
| What is a nomotropic disturbance that is physiological (normal) in dogs? | sinus arrhythmia |
| What is a characteristic of 2nd degree AV block? | dropped beats |
| What can create the appearance of atrial fibrillation in a normal dog? | electrical interference |
| Moderate damage to the heart can cause what other actions by the body ? | kidneys to retain fluid |
| Maximum cardiac output is limited by what factor? | stroke volume and heart rate |
| Sinus bradycardia is an issue with what? | SA node establishing a rate that is too low |
| What can cause an interruption of signal between the AV node and the Bundle of His? | extreme vagal tone, infection, ischemia |
| A stenotic aortic valve would create a murmur during what event? | systole |
| What is a signal on an EKG of supraventricular extrasystole? | negative P wave |
| Ventricular extrasystole is characterized by what EKG event? | inverted T wave |
| What is a decrease or stoppage in the rate of conduction of the impulse through the AV node and Bundle of His? | AV block |
| How may heart failure manifest itself? | overloading the heart through increased cardiac output |
| What grade of heart murmur has a loud murmur without a palpable thrill? | 4 |
| On an ECG what event indicates the presence of a myocardial infarction? | deep Q wave |
| What event occurs during 3rd degree AV block? | atria and ventricles beat at different rates |
| What characterizes an incompetent murmur? | valvular insufficiency |
| Which is not a type of heart failure? | low pressure |
| What is a sign of a shifting pacemaker? | altered P wave or PQ segment |
| What happens after initial heart failure? | edema, overstretching of the heart muscle, ventricular dialation |
| When the right heart fails, edema or fluid buildup occurs where? | abdomen |
| Arterio-venous shunts and low resistance to blood flow cause what type of heart failure? | high output |
| How do ventricular septal defects cause heart failure? | thickening of the left ventricle |
| What type of vessels normally regulate blood flow? | arterioles |
| What is caused by a metabolic vitamin B deficiency? | loss of arteriolar tone |
| What happens in extreme cases of ventricular hypertrophy? | inability to eject enough blood |
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