Term
| Stage 1. Ventricular Filling |
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Definition
atria and ventricles relaxed
mitral and tricuspid valves wide open
*aortic and semilunar valves closed
*blood rushes passively from venae cavae to atria to ventricles
*70 percent of filling here |
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Term
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Definition
atria contract; topping amount of blood filled in ventricles by another 30 percent which will fill them completely.
-atria then relax which is a stage known as atrial diastole |
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Term
| Stage 3: Isovolumic Ventricular Contraction |
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Definition
S1 SOUND
-First phase of ventricular systole
-ventricles contract, pressure rises in their interiors and exceeds pressure in the atria which cause AV valves to close. |
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Term
| Stage 4: Ejection into Aorta |
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Definition
Pressure in ventricles>Pressure in Pulmonary Artery/Aorta
Which Causes: semilunar valves to passively open and blood is ejected out from ventricles into pulmonary systemic circuits |
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Term
| Stage 5: Isovolumic ventircular Relaxation |
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Definition
S2 SOUND
-Pressure in ventricles starts to fall below pressure in pulmonary arteries and aorta.
CAUSES: semilunar valves close passively and pressure in ventricles starts to fall. ALL 4 VALVES CLOSED |
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Term
| Stage 6: Ventricular Filling Again |
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Definition
Pressure in ventricles falls below pressure in atria.
CAUSES: A-V valves to open, causing blood to enter into relaxed ventricles. |
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Term
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Definition
onset of ventricular systole; closure of A-V valves and tensing of chordae tendinae
(mitral valve closes ahead of tricuspid valve) |
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Term
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Definition
| occurs when semilunar valves close and marks the end of the ventricular systole. (aortic valve closes ahead of pulmonic valve) |
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Term
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Definition
| mitral valve defect; blood regurgitates into corresponding atrium during ventricular systole. LV pressure > LA pressure |
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Term
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Definition
| Aortic or Pulmonic Valves do not close properly. Blood regurgitates into ventricles during ventricular diastole. Pulmonic and aortic valves should be closed. |
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Term
| 4 Factors that Affect Cardiac Output |
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Definition
1. Preload
2. Afterload
3. Heartrate
4. Myocardial Contractility |
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Term
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Definition
| amount of blood returning to heart (EDV) |
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Term
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Definition
| resistance to ejection of blood from ventricles |
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Term
| 3 Factors afterload is affected by Afterload |
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Definition
1. Pressure in the aorta
2. TPR determined by arteriole diameters and by vasoconstriction
3. Pathological Changes |
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Term
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Definition
| Force of contraction of cardiac muscle at given fiber length. |
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Term
| 3 factors affecting myocardial contractility |
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Definition
1. Norepinephrine and Epinephrine
2. Increased extracellular calcium
3. Digitalis: Causes increased intracellular calcium |
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Term
| 4 Factors that Determine Blood Pressure |
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Definition
1. Cardiac Output
2. TPR
3. Capacity of Venous System
4. Volume of Fluid in Circulatory System |
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Term
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Definition
| stretch receptors in walls of arteries |
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Term
| Contraction of Myocardium |
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Definition
1.Triggered by rhythmic depolarization of the cells in the SA node
2. Spreads to ventricles via specialized myocardial cells that make up the conduction system of the heart
3. Myocardium depolarized, process of repolarization begins. Apical surface myocardium repolarizes little earlier than basal region. |
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Term
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Definition
| depolarization of the atria, indicates SA node function |
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Term
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Definition
time it takes impulse to pass through the
A-V node into the ventricles |
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Term
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Definition
| time when ventricular depolarization begins |
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Term
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Definition
| between QRS complex and T wave. Used for diagnostic purposes. Elevation or depression with respect to baseline can be important in detecting myocardial infarction. |
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Term
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Definition
Re-polarization of the ventricles and are ready to be stimulated again.
INVERSION= myocardial infarction |
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Term
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Definition
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Term
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Definition
| Systolic Aortic Pressure - Diastolic Aortic Pressure |
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Term
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Definition
| Diastolic Aortic Pressure + 1/3 Pulse Pressure |
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Term
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Definition
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Term
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Definition
| Mean Blood Pressure/Cardiac Output |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Cause Cardiac Output to increase more. |
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