REGULATION OF CARDIAC OUTPUT AND TPR Flashcards
WHAT IS CARDIAC OUTPUT?
THE AMOUNT OF BLOOD PUMPED BY EACH VENTRICLE IN ONE MIN.
FORMULA FOR CO.
CO= HR x SV
DEFINE SV.
THE AMOUNT OF BLOOD EJECTED BY EACH VENTRICLE PER BEAT/ CARDIAC CYCLE
CARDIAC OUTPUT IS THE SAME AS
VENOUS RETURN
STATE THE FACTORS AFFECTING THE HR.
- AUTONOMIC NERVOUS SYSTEM - SYMPATHETIC HAS HIGHER HR
- AGE - AS THE AGE INCREASES, THE HR DECREASES
- HORMONES - CATHECOLAMINES WILL CAUSE THE HR TO INCREASE
- FITNESS LEVEL - AS THE FITNESS LEVEL OF AN INDIVIDUAL INCREASES, THE HR DECREASES.
STATE THE FACTORS THAT AFFECTING THE STROKE VOLUME.
- PRELOAD
- AFTERLOAD
- CONTRACTILITY
DEFINE EDV
THE VOLUME OF BLOOD IN VENTRICLES AT THE END OF VENTRICULAR DIASTOLE.
DEFINE ESV.
THE VOLUME OF BLOOD LEFT IN THE VENTRICLE AT THE END OF VENTRICULAR SYSTOLE
WHAT IS MEANT BY EJECTION FRACTION
FRACTION OF END DIASTOLIC VOLUME THAT IS EJECTED (SV/EDV)
PRELOAD IS RAISED DURING:
- FILLING TIME INCREASES
- VENOUS RETURN INCREASES
WHAT HAPPEN TO THE CO WHEN THE PRELOAD INCREASE?
FILLING TIME INCREASE -> PRELOAD INCREASE -> EDV INCREASE -> CO INCREASE
WHAT HAPPEN TO THE CO WHEN THE AFTERLOAD INCREASE?
SEMILUNAR VALVE DAMAGE -> ESV INCREASE -> SV DECREASE -> AFTERLOAD INCREASE -> CO DECREASE
AFTERLOAD IS RAISED WHEN:
THERE IS DAMAGE TO THE SEMILUNAR VALVE
INCREASED IN THE VASCULAR RESISTANCE
PRELOAD IS REDUCED WHEN:
- DECREASED IN THE THYROID HORMONE
- DECREASE IN THE CA++
- HIGH OR LOW K+
- HIGH OR LOW NA++
- LOW BODY TEMP
- HYPOXIA
- ABNORMAL PH BALANCE
- DRUG SUCH AS CCB
AFTERLOAD IS REDUCED WHEN:
DECREASED THE VASCULAR RESISTANCE
