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The Heart

Chapter 18

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The HeartHeart function = key factor in body functionHealth Issues – Heart problems are one of the leading

causes of death in the US

Primary function♦Blood circulation♦There must be enough force generated to send blood to

every single cellAs A Pump

♦Pumps 1835 gallons of blood a day♦Through 60,000 miles of blood vessels

What’s your heart doing right now?

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Heart - LocationRemember those body cavities….?Mediastinum = the cavity between the lungs

♦Holds•Trachea•Thymus•Pericardial cavity

Inside the pericardial cavity…♦Heart + Pericardium

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Fig. 18-1

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Fig. 18-1

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Heart - Anatomy Chambers

♦Atria♦Ventricles

Arteries♦Pulmonary♦Aorta♦Coronary

Veins♦Pulmonary♦Vena Cava♦Coronary

Valves♦Atrioventricular♦Semilunar

Conduction Nodes (electrical) & Fibers Fig. 18.3

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Heart - Anatomy Chambers

♦Atria♦Ventricles

Arteries♦Pulmonary♦Aorta♦Coronary

Veins♦Pulmonary♦Vena Cava♦Coronary

Valves♦Atrioventricular♦Semilunar

Conduction Nodes (electrical) & Fibers Fig. 18.3

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Heart - Anatomy Chambers

♦Atria♦Ventricles

Arteries♦Pulmonary♦Aorta♦Coronary

Veins♦Pulmonary♦Vena Cava♦Coronary

Valves♦Atrioventricular♦Semilunar

Conduction Nodes (electrical) & Fibers Fig. 18.6

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Heart – Anatomy: ChambersThere are 3 layers of tissue

♦Epicardium = visceral layer♦Myocardium = cardiac muscle♦Endocardium (innermost) = squamus epithelium (thin layer)

Fig. 18.4

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Heart – Anatomy: ChambersThere are 3 layers of tissue

♦Epicardium = visceral layer♦Myocardium = cardiac muscle♦Endocardium (innermost) = squamus epithelium (thin layer)

♦Thickness of the myocardium is variable♦It’s made of cardiac muscle – do you recall any special

features of cardiac muscle?

♦Intercalated discs…♦How does that relate to cell function?♦Coordinated action potential for contraction

Fig. 18.6

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Heart – Anatomy: Cardiac muscle

Fig. 18.5

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Heart – Anatomy: Chambers

Fig. 18.6

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Heart – Anatomy

Fig. 18.7

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Heart – Anatomy: Chambers

Fig. 18.7

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Heart – Anatomy

Fig. 18.8a

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Heart – Anatomy: Chambers

Fig. 18.8b

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Heart – Anatomy: Chambers

Fig. 18.9

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Heart – Anatomy: Chambers

Fig. 18.9

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Heart – Anatomy

Fig. 18.6

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Heart – Anatomy

Fig. 18.6

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Heart – Anatomy

Fig. 18.6

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Fig. 17-10