2/6/08 The Heart Chapter 18

2/6/08 The Heart  Heart function = key factor in body function  Health 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 cell  As A Pump ♦Pumps 1835 gallons of blood a day ♦Through 60,000 miles of blood vessels  What’s your heart doing right now?

2/6/08 Heart - Location  Remember those body cavities….?  Mediastinum = the cavity between the lungs ♦Holds Trachea Thymus Pericardial cavity  Inside the pericardial cavity… ♦Heart + Pericardium

2/6/08 Fig. 18-1

2/6/08 Fig. 18-1

2/6/08 Heart - Anatomy  Chambers ♦Atria ♦Ventricles  Arteries ♦Pulmonary ♦Aorta ♦Coronary  Veins ♦Pulmonary ♦Vena Cava ♦Coronary  Valves ♦Atrioventricular ♦Semilunar  Conduction Nodes (electrical) & Fibers Fig. 18.3

2/6/08 Heart - Anatomy  Chambers ♦Atria ♦Ventricles  Arteries ♦Pulmonary ♦Aorta ♦Coronary  Veins ♦Pulmonary ♦Vena Cava ♦Coronary  Valves ♦Atrioventricular ♦Semilunar  Conduction Nodes (electrical) & Fibers Fig. 18.3

2/6/08 Heart - Anatomy  Chambers ♦Atria ♦Ventricles  Arteries ♦Pulmonary ♦Aorta ♦Coronary  Veins ♦Pulmonary ♦Vena Cava ♦Coronary  Valves ♦Atrioventricular ♦Semilunar  Conduction Nodes (electrical) & Fibers Fig. 18.6

2/6/08 Heart – Anatomy: Chambers  There are 3 layers of tissue ♦Epicardium = visceral layer ♦Myocardium = cardiac muscle ♦Endocardium (innermost) = squamus epithelium (thin layer) Fig. 18.4

2/6/08 Heart – Anatomy: Chambers  There 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

2/6/08 Heart – Anatomy: Cardiac muscle Fig. 18.5

2/6/08 Heart – Anatomy: Chambers Fig. 18.6

2/6/08 Heart – Anatomy Fig. 18.7

2/6/08 Heart – Anatomy: Chambers Fig. 18.7

2/6/08 Heart – Anatomy Fig. 18.8a

2/6/08 Heart – Anatomy: Chambers Fig. 18.8b

2/6/08 Heart – Anatomy: Chambers Fig. 18.9

2/6/08 Heart – Anatomy: Chambers Fig. 18.9

2/6/08 Heart – Anatomy Fig. 18.6

2/6/08 Heart – Anatomy Fig. 18.6

2/6/08 Heart – Anatomy Fig. 18.6

2/6/08 Fig