THE HEART
FUNCTION• TO PUMP BLOOD THROUGH THE BODY
VIA THE ARTERIES, CAPILLARIES, AND VEINS
DID YOU KNOW…THE HEART BEAT BEGINS AT 4 WEEKS
ENUTERO
LOCATION• IN THE THORACIC CAVITY IN THE
MEDIASTINUM• THE BASE IS AT THE TOP AND THE APEX IS AT THE BOTTOM JUST LEFT OF THE MIDLINE
CARDIAC MEMBRANES• PARIETAL PERICARDIUM – LINES THE CAVITY• VISCERAL PERICARDIUM – ON THE SURFACE OF THE HEART
LAYERS OF THE HEART• EPICARDIUM – OUTERMOST LAYER OF
THE HEART TISSUE• MYOCARDIUM – MUSCLE THAT MAKES
UP THE CHAMBERS OF THE HEART• ENDOMETRIUM – INNER LAYER THAT IS
SMOOTH TO PREVENT ABNORMAL BLOOD CLOTTING. IT MAKES UP THE VALVES.
CHAMBERS OF THE HEART• UPPER CHAMBERS – LEFT AND RIGHT
ATRIA SEPARATED BY THE INTERATRIAL SEPTUM
• LOWER CHAMBERS – LEFT AND RIGHT VENTRICLES SEPARATED BY THE INTERVENTRICULAR SEPTUM
FLOW OF BLOOD• BLOOD ENTERS THE HEART FROM THE BODY VIA THE
SUPERIOR AND INFERIOR VENA CAVA• TRAVELS TO THE RIGHT ATRIUM• PASSES THROUGH THE RIGHT AV VALVE (TRICUSPID
VALVE)• TRAVELS TO THE RIGHT VENTRICLE• PASSES THROUGH THE PULMONARY SEMILUNAR VALVE• TRAVELS THROUGH THE PULMONARY ARTERY TO THE
LUNGS• BLOOD HAS BEEN DEOXYGENATED AND NEEDS TO GO
TO THE LUNGS TO PICK UP OXYGEN (BECOMES OXYGENATED BLOOD)
FLOW OF BLOOD• BLOOD LEAVES LUNGS AND REENTERS HEART
THROUGH 4 PULMONARY VEINS• TRAVELS TO THE LEFT ATRIUM• PASSES THROUGH THE LEFT AV VALVE
(BICUSPID AKA MITRAL VALVE)• TRAVELS TO THE LEFT VENTRICLE• PASSES THROUGH THE AORTIC SEMILUNAR
VALVE• EXITS THE HEART THROUGH THE AORTA
FLOW OF BLOOD• BLUE –• DEOXYGENATED
• RED –• OXYGENATED
PARTS OF THE AORTA
• ASCENDING• AORTIC ARCH• DESCENDING• THORACIC• ABDOMINAL
VALVES• PREVENT THE BACKFLOW OF BLOOD
CARDIAC CYCLE• PULSE – “LUB DUB”• FIRST SOUND IS THE CONTRACTION OF THE
VENTRICLES CLOSING THE AV VALVES (LUB)• SECOND SOUND IS THE CLOSURE OF THE
AORTIC AND PULMONARY SEMILUNAR VALVES (DUB)
• MURMUR – VALVE DOESN’T CLOSE PROPERLY
PULSE RATES• NORMAL – RESTING PULSE IS 60 - 90• BRADYCARDIA – RESTING PULSE LESS
THAN 60 • TACHYCARDIA – RESTING PULSE
GREATER THAN 100
BLOOD PRESSURE• SYSTOLIC/DIASTOLIC• SYSTOLE – CONTRACTION OF THE
CHAMBERS OF THE HEART• DIASTOLE – RELAXATION OF THE
CHAMBER OF THE HEART• HYPERTENSION – BP GREATER THAN
140/90
CARDIAC CONDUCTION• CARDIAC MUSCLE HAS THE ABILITY TO
CONTRACT SPONTANEOUSLY• SA NODE – NATURAL PACEMAKER OF
THE HEART LOCATED IN WALLS OF RIGHT ATRIUM
• IMPULSE TRAVELS TO THE AV NODE AND CONTINUES THROUGHOUT HEART
CORONARY ARTERIES• SUPPLY BLOOD AND OXYGEN TO THE
HEART• FIRST BRANCHES OFF THE ASCENDING
AORTA
REGULATION OF THE HEART• MEDULLA OBLONGATA