The Cardiovascular SystemThe Heart

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FUNCTIONS OF THE HEARTGenerating blood pressureRouting blood

• Heart separates pulmonary and systemic circulations

Ensuring one-way blood flow• Heart valves ensure one-way flow

Regulating blood supply• Changes in contraction rate and force match blood

delivery to changing metabolic needs

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SIZE, SHAPE, LOCATION OF THE HEART

Size of a closed fistShape

• Apex: Blunt rounded point of cone

• Base: Flat part at opposite of end of cone

Located in thoracic cavity

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HEART CROSS SECTION

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HEART WALLThree layers of tissue

• Epicardium: This serous membrane of smooth outer surface of heart

• Myocardium: Middle layer composed of cardiac muscle cell and responsibility for heart contracting

• Endocardium: Smooth inner surface of heart chambers

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HEART WALL LAYERS

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HEART WALL LAYERS

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EXTERNAL ANATOMYFour chambers

• 2 atria• 2 ventricles

Auricles• a small, muscular pouch

at the upper corner of the atrium

Major veins• Superior vena cava• Pulmonary veins

Major arteries• Aorta• Pulmonary trunk

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EXTERNAL ANATOMY

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HEART VALVES

Atrioventricular• Tricuspid• Bicuspid or mitral

Semilunar• Aortic• Pulmonary

Prevent blood from flowing back

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HEART VALVES

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FUNCTION OF THE HEART VALVES

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BLOOD FLOW THROUGH HEART

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INTERACTIVE HEARTGo to:http://www.innerbody.com/image_card02/card51-new.html And use the inteactive explorer to practice your knowledge of the heart.