Transcript CH12

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THE CARDIOVASCULAR SYSTEM
• THE HEART PUMPS BLOOD THROUGH A
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CLOSED SYSTEM OF BLOOD VESSELS.
ARTERIES CARRY BLOOD AWAY FROM HEART
INTO BODY TISSUE CAPILLARIES.
VEINS CARRY BLOOD FROM BODY TISSUE
CAPILLARIES BACK TO HEART.
RED VESSELS CARRY OXYGENATED BLOOD.
BLUE VESSELS CARRT DEOXYGENATED BLOOD.
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THE CARDIOVASCULAR SYSTEM
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THE HEART
• IS A MUSCULAR PUMP LOCATED WITHIN
THE THORACIC CAVITY BETWEEN THE
LUNGS AND THE DIAPHRAGM.
• IT IS COVERED BY A TOUGH FIBROUS
SAC CALLED THE PERICARDIUM.
• THE HEART WALL IS MADE OF A THICK
MUSCLE BETWEEN TWO MEMBRANES:• ENDOCARDIUM – MYOCARDIUM - EPICARDIUM
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THE HEART LOCATION
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THE HEART WALL STRUCTURE
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THE HEART CHAMBERS
THE HEART HAS FOUR CHAMBERS:• LEFT & RIGHT ATRIUM:- THE TWO UPPER
CHAMBERS THAT RECEIVE THE BLOOD
RETURNED TO THE HEART BY VEINS.
• LEFT & RIGHT VENTRICLE:- THE TWO LOWER
CHAMBERS THAT PUMP BLOOD INTO ARTERIES
• ATRIAL SEPTUM SEPARATE THE ATRIA.
• VENTRICULAR SEPTUM SEPARATE VENTRICLES.
• FIBROUS RING SEPARATE ATRIA & VENTRICLES
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THE HEART CHAMBERS
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THE HEART BLOOD VESSELS
• CORONARY VESSELS:- SUPPLY BLOOD TO THE
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HEART STRUCTURES.
AORTA:- CARRY BLOOD FROM THE LEFT
VENTRICLE INTO THE SYSTEMIC CIRCULATION.
PULMONARY ARTERY:- CARRY BLOOD FROM
THE RIGHT VENTRICLE INTO THE LUNGS.
PULMONARY VEINS:- BRING BLOOD FROM THE
LUNGS INTO THE LEFT ATRIUM.
THE VENA CAVA:- BRING BLOOD FROM THE
VEINS INTO THE RIGHT ATRIUM.
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THE HEART BLOOD VESSELS
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THE HEART VALVES
• ALLOW BLOOD TO FLOW ONLY IN ONE
DIRECTION FROM OR INTO THE HEART.
ATRIOVENTRICULAR VALVES {A-V VALVES}
• MITRAL {BICUSPID} VALVE:- LOCATED
BETWEEN LEFT ATRIUM & L. VENTRICLE.
• TRICUSPID VALVE:- LOCATED BETWEEN
RIGHT ATRIUM & RIGHT VENTRICLE.
• ALLOW BLOOD TO FLOW ONLY FROM
EACH ATRIUM INTO EACH VENTRICLE.
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THE HEART VALVES
SEMILUNAR VALVES:• AORTIC SEMILUNAR VALVE:- LOCATED AT
THE ENTERANCE OF THE AORTA. IT
ALLOW BLOOD FLOW ONLY FROM THE
LEFT VENTRICLE INTO THE AORTA.
• PULMONARY SEMILUNAR VALVE:LOCATED AT THE ENTRANCE OF THE
PULMONARY ARTERY. IT ALLOW BLOOD
FLOW ONLY FROM RIGHT VENTRICLE
INTO PULMONARY ARTERY.
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THE HEART VALVES
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THE HEART VALVES
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HEART CONDUCTION SYSTEM
• IT IS SPECIALIZED MUSCLE TISSUE THAT
FUNCTION LIKE NERVES BY GENERATING
SPONTANOUS IMPULSES & TRANSMITING
THEM TO THE HEART MUSCLE TO CAUSE
CONTRACTION. CONSIST OF:• SINOATRIAL {SA} NODE
• ATRIOVENTRICULAR {AV} NODE
• ATRIOVENTRICULAR {AV} BUNDLE
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• PURKINJE FIBERS
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ELECTROCARDIOGRAM
• THE ORIGINATION & TRANSMISSION OF
IMPULSES THROUGH THE CONDUCTION
SYSTEM OF THE HEART WILL GENERATE
ELECTRICAL CURRENTS THAT CAN BE
DETECTED BY ELECTRODES PLACED ON
THE BODY SURFACE.
• AN ELECTROCARDIOGRAPH MACHINE IS
USED TO TRANSFORM THE ELECTRICAL
CURRENTS INTO A DRAWING CALLED
ELECROCARDIOGRAM {ECG} OR {EKG}
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ELECTROCARDIOGRAM
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ELECTROCARDIOGRAM
• THE IMPULSES ORIGINATE FROM THE
SINOATRIAL {SA} NODE AND AS THEY
ARE TRANSMITTED THROUGH THE
HEART THEY GENERATE:• P-WAVE:- DEPOLARIZATION OF ATRIA.
• QRS WAVE:- DEPOLARIZATION OF THE
VENTRICLES.
• T-WAVE:- REPOLARIZATION OF THE
VENTRICLES.
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THE CARDIAC CYCLE
• RIGHT ATRIUM FILLED WITH VENOUS
DEOXYGENATED BLOOD BY VENA CAVA.
• LEFT ATRIUM FILLED WITH OXYGENATED
BLOOD FROM BOTH LUNGS BY THE
PULMONARY VEINS.
• ATRIOVENTRICULAR VALVES OPEN AND
BLOOD FLOW FROM RIGHT ATRIUM INTO
RIGHT VENTRICLE & FROM LEFT ATRIUM
INTO LEFT VENTRICLE.
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THE CARDIAC CYCLE
• LEFT VENTRICLE CONTRACTION CLOSE
THE MITRAL VALVE, OPEN THE AORTIC
SEMILUNAR VALVE AND EJECT BLOOD
THROUGH THE AORTA INTO THE
SYSTEMIC CIRCULATION.
• RIGHT VENTRICLE CONTRACTION CLOSE
TRICUSPID VALVE, OPEN PULMONARY
SEMILUNAR VALVE AND EJECT BLOOD
THROUGH PULMONARY ARTERY INTO
PULMONARY CIRCULATION.
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THE CARDIAC CYCLE
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THE CARDIAC CYCLE
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THE CARDIAC CYCLE
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ARTERIAL BLOOD PRESSURE
• SYSTOLIC BLOOD PRESSURE:- HIGHEST
BLOOD PRESSURE REACHED WHEN THE
VENTRICLE ARE CONTRACTING.
• DIASTOLIC BLOOD PRESSURE:- LOWEST
BLOOD PRESSURE REACHED WHEN THE
VENTRICLES ARE RELAXING.
• PULSE PRESSURE:- THE DIFFERENCE
BETWEEN SYSTOLIC AND DIASTOLIC
PRESSURES.
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ARTERIAL BLOOD PRESSURE
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PULSE PRESSURE
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REGULATION OF THE HEART
• DONE BY THE CARDIAC CENTER IN THE
MEDULLA OBLONGATA OF THE BRAIN.
• SYMPATHETIC IMPULSES INCREASE THE
HEART RATE & CONTRACTION FORCE BY
SECRETING NOREPINEPHRINE.
• PARASYMPATHETIC IMPULSES DECREASE
ONLY THE HEART RATE BY SECRETING
ACETYLCHOLINE.
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REGULATION OF THE HEART
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THE BLOOD VESSELS
• AORTA > LARGE ARTERIES > SMALL
ARTERIES > ARTERIOLES > CAPILLARIES
• CAPILLARIES > VENULES > SMALL VEINS
> LARGE VEINS > VENA CAVA.
• ARTERIAL & VENOUS CAPILLARIES FORM
CAPILLARY BEDS WHERE EXCHANGE OF
NUTRIENTS & WASTE PRODUCTS OCCUR
BETWEEN BLOOD AND BODY TISSUES.
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A CAPILLARY BED
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SYSTEMIC ARTERIES
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SYSTEMIC VEINS
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ARTERIES SUPPLYING THE HEAD
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VEINS DRAINING THE HEAD
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