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TLL CH18 HEART
HEART
| Question | Answer |
|---|---|
| ISOVOLUMETRIC CONTRACTION IS PHASE | ALL VALES ARE CLOSED PHASE 2 |
| EJECTION PHASE | VENT PRESSURE EXCEEDS PRESSURE IN THE LG ARTIES, FORCING THE SL VALVES OPEN |
| END SYSTOLIC VOLUME | VOLUME OF BLOOD REMAINING IN EACH VENTRICLE |
| ISOVOLUMETRIC REAXATION | OCCURS IN EARLY DIASTOLE |
| CO= | HR X SV= |
| CARDIAC OUTPUT | VOLUME OF BLOOD PUMPED BY EACH VENT IN ONE MINUTE |
| THREE MAIN FACTORS FOR SV | PRELOAD...CONTRACTILITY.....AFTERLOAD |
| PRELOAD | DEGREE OF STRENCH OF CARDIAC MUSCLE CELLS BEFORE THEY CONTRACT |
| FRANK STARLING LAW | THE AMOUNT OF STRECTCHING OF CARDIAC MUSCLE FIBERS HELPS REGULATE STOKE VOLUME AND MAINTAIN EQUAL OUTPUT FROM BOTH VENTRICLES |
| CONTRACTILITY | CONTRACTILE STRENGTH AT A GIVEN MUSCLE LENTH, INDEPENDENT OF MUSCLE STRETCH AND EVD |
| POS INOTROPIC AGENTS | INCREASE CONTRACTILILY, INCREASE CA, HORMONES THYROXINE, GLUCAGON, EPI |
| NEG INOTROPIC AGENTS | DECREASE CONTRACTILITY, ACIDOSIS, INCREASE EXTRACELLUR "K", CA CHANNEL BLOCKERS |
| AFTERLOAD | PRESSURE THAT MUST BE OVERCOME FOR VENTRICLES TO EJECT BLOOD |
| POS CHRONOTROPIC FACTORS | INCREASE HR |
| NEG CHONOTROPIC FACTERS | DECREASE HR |
| SYMPATHETIC NERVOUS SYSTEM | IS ACTIVATED BY EMOTIONAL OR PHY STRESSORS |
| NOREPINEPHRINE | CAUSE THE PACEMAKER TO FIRE MORE RAPILY(AND AT THE SAME TIME INCREASES CONTRACTILITY) |
| AT REST THE CARDIAC MUSCLES ARE | SHORTER THAN OPTIMAL LENGTH |
| WHAT INCREASES VENOUS RETURN | SLOW HEARTBEAT AND EXERCISE |
| INCREASED VENOUS RETURN...... | DISTENDS THE VENTRICLES AND INCREASES CONTRACTION FORCE |
| VENOUS RETURN | THE FLOW OF BLOOD BACK TO THE HEART |
| ATRIAL (BAINBRIDGE) REFLEX | A SYPATHETIC REFLEX INTIATED BY INCREASED VENOUS RETURN |
| EPINEPHRINE FROM ADRENAL MEDULLA | ENHANCES HEARTRATE AND CONTRACTILILY |
| THYROXINE | INCREASE HR ION CONCENTRATIONS(CA,K)MUST BE MAINTAINED FOR NORMAL HEART FUNCTION |
| SUPERFICIAL FIBROUS PERICARDIUM...FUNCTIONS | PROTECS, ANCHORS AND PREVENTS OVER FILLING |
| DEEP TWO LAYED PERICARDIUM | SEROUS PERICARDIUM |
| PARIETAL LAYER | LINES THE INTERNAL SURFACE OF THE FIBROUS PERICARDIUM |
| VISCERAL LAYER (EPICARDIUM) | ON EXTERNAL SURFACE OF THE HR |
| PERICARDIAL CAVITY | SEPARATED BY FLUID FILLED (HELPS DECREASE FRICTION) |
| MYOCARDIUM | SPIRAL BUNDLES OF CARDIAC MUSCLE CELLS |
| FIBROUS SKELETON OF THE HEART | CRISSCROSSING, INTERLACING LAYER OF CONNECTIVE TISSUE |
| MYOCARDIUM (FUNCTION) | ANCHORS CARDIAC MUSCLE FIBERS SUPPORTS GREART VESS AND VALVES LIMITS SPREAD OF ACTION POTENTIALS TO SPECIFIC PATHS |
| ENDOCARDIUM | CONTINUOUS WITH ENDOTHELIAL LINING OF BLOOD VESS |
| PULMONARY CIRCUIT | IS A SHORT LOW PRESSURE CIRCULATION |
| SYSTEMIC CIRCUIT | BLOOD ENCOUNTER MUCH RESTANCE IN THE LONG PATHWAYS |
| ARTERIA | SUPPLY VARIES CONSIDERABLY AND CONTAINS MANY ANASTOMOSES (JUNCTIONS) AMONG BRANCHES |
| ARTERIES ON THE HEART | RT & LT CORONARY, MARGINAL, CIRCUMFLEX, AND ANTERIOR INTERVENTRICLAR ARTERIES |
| VEINS | SMALL CARDIAC, ANTERIOR CARDIAC AND GREAT CARDIAC VEINS |
| CARDIAC MUSCLE CELLS | SHORT, FAT, BRANCHED, STRIATED, AND INTERCONNECTED |
| CONNECTIVE TISSUE MATRIX (ENDOMYSIUM) | CONNECTS TO THE FIBROUS SKELETON |
| INTERCALATED DISC | JUNCTIONS BETWEEN CELLS ANCHOR CARDIAC CELLS |
| DESMOSOMES (BOND) | PREVENT CELLS FROM SEPARTING DURING CONTRCTION |
| GAP JUNCTIONS | ALLOW IONS TO PASS; ELECTRICALLY COUPLE ADJACENT CELLS AND ENSURES THE HEART CONTRACTS AS A UNIT |
| HEART MUSCLE BEHAVES AS A....... | FUNCTIONAL SYNCYTIUM |
| DEPOLARIZATION OF THE HEART IS..... | RYTHMIC AND SPONTANEOUS ABOUT 1% OF CARDIAC CELLS HAVE AUTOMATICITY |
| DEPOLARIZATION OPENS..... | VILTAGE-GATED FAST NA CHANNELS IN THE SARCOLEMMA |
| DEPOLARIZATION WAVE IN T TUBLES CAUSES.... | THE SR TO RELEASE CA |
| DEPOLARIZATION WAVE ALSO...... | OPENS SLOW CA CHANNELS IN THE SARCOLEMMA |
| WHAT PROLONGS THE DEPOLARIZATION PHASE (PLATEAU) | CA SURGE |