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