512027
Description
Flashcards by ecmarchese, updated more than 1 year ago
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Created by ecmarchese
almost 11 years ago
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| Question | Answer |
| Specialized muscle cells _____ produce and transmit electrical impulses to create contraction and relaxation of the heart. | Myocytes |
| What are the components of the conduction system? | SA node, AV node, bundle of his, bundle branches, purkinje fibers |
| Known as the pacemaker of the heart. Located at the border of the SVC and RA. | SA node |
| What does the AV node do? | Delays impulses to let the ventricles fill with blood. |
| What is the normal pacing of the AV node? | 40-60 in the AV junction, 20-40 in the ventricles |
| Receives impulses from the AV node and conducts the depolarization wave to the apex. | Bundle of his |
| Stimulation of ______ fibers causes depolarization of the cells and contraction occurs. | Purkinje fibers |
| The heart contract from? | The inside to the outside |
| Where does depolarization begin? | Begins at the apex and moves to the base |
| The p wave represents? | Atrial depolarization |
| The QRS wave represents? | Ventricular depolarization |
| The T wave represents? | Ventricular repolarization |
| What 2 nervous systems affect the heart rate? | Sympathetic, parasympathetic |
| Fibers attached to the SA and AV nodes via the vagus nerves controlling heart rate | Sympathetic nervous system |
| What does the sympathetic nervous system do? | Increase HR and increase contraction |
| What is derived from the vagal cardiac nerves located in the neck? | Parasympathetic nervous system |
| What does the parasympathetic nervous system do? | Decrease HR and decrease force of contraction |
| Timing from the beginning of one heart beat to the next. | Cardiac cycle |
| This begins with the closure of the semilunar valves, on EKG it is the end of the T wave to the onset of QRS | Ventricular diastole |
| What are the 3 events of ventricular diastole? | Isovolumic relaxation, passive filling, atrial systole |
| This occurs from the closure of the semilunar valves to the opening of the atrioventricular valves. | Isovolumic relaxation |
| What 3 stages are in the passive filling stage? | Rapid filling, reduced filling, equalization |
| Blood enters the ventricles passively yet rapidly due to swift ventricular relaxation. | Rapid filling |
| Flow is reduced and pressures begin to equalize. | Reduced filling |
| Pressures equalize before mid-late diastolic pressures begin to rise. | Equalization |
| During atrial contraction, how much blood is forced into the ventricles? | 1/3 |
| Closure of the AV valves | S1 |
| Closure of the semilunar valves | S2 |
| Opening of the AV valves | S3 |
| Atrial systole | S4 |
| What are the RA pressures? | Mean- 0-8 mmhg |
| What are the RV pressures? | Peak systolic- 16-30 mmhg, end diastolic- 0-8 mmhg |
| What are the PA pressures? | Peak systolic- 16-30 mmhg, end diastole- 0-8 mmhg |
| What are the LV pressures? | Peak systolic- 100-140 mmhg, end diastolic- 3-12 mmhg |
| What are the LA pressures? | Mean- 0-12 mmhg |
| What are the aortic pressures? | Peak systolic- 100-140 mmhg, end diastolic- 60-90 mmhg |
| What is an abnormal heart sound that is caused by turbulent flow in the heart or great vessels? | Heart murmurs |
| What are the components of the pulmonary system? | Right ventricle, main pulmonary arteries, pulmonic capillaries, pulmonary veins |
| What are the components of the systemic circulation? | Left ventricle, aorta, systemic capillary network, cerebral, abdominal, and peripheral veins, and superior and inferior vena cava |
| Amount of blood ejected from the LV into the aorta | Cardiac output |
| What is the equation for cardiac output? | Stroke volume x bpm |
| The volume of blood ejected with each beat | Stroke volume |
| What is the equation for stroke volume? | EDV- ESV |
| The hearts ability to increase cardiac output is dependent on what 4 things? | Preload, after load , Inotropic force, chronotropic force |
| Filling of the heart during diastole | Preload |
| The resistance that the heart must pump against | After load |
| Contractility of the heart muscle ( force of contraction) | Inotropic force |
| Heart rate or the rate of contraction | Chronotropic force |
| What does the frank starling rule state? | The more blood that enters the ventricle, the greater amount of blood that must be pumped out during systole |
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