Heart

Figure 22.02b

Heart

Functions of the Heart

Ensures unidirectional flow of blood

Pumps blood to lungs and body

Develops blood pressure for nutrient and waste exchange

Figure 22.01

Heart-Anatomical Location and Orientation

Heart Anatomical Orientation and Location

Chambers of the Heart

• Atria • (Left and

Right)

• Ventricles (Left and Right)

Heart Valves

• Atrioventricular (AV) valves – between atria and ventricles

• Semilumar Valves– between ventricles and great arteries

Valves of the Heart

Heart Valves

Figure 18.8a

Atrioventricular Valves (Open)

Atrioventricular Valves (Closed)

Figure 18.9b

Semilunar Valves (Open vs Closed)

Figure 18.10a, b

Pericardium

Layers of the Heart

Layers of the Heart

Figure 18.3

EpicardiumMyocardiumEndocardium

Cardiac Muscle Cells

Cardiac Muscle Cells

Blood Flow Through the Heart

Figure 22.06ab

Conduction System

• Cardiac muscle tissue has intrinsic ability to:

• Generate and conduct impulses

• Signal these cells to contract rhythmically

• Conducting system

• A series of specialized cardiac muscle cells

• Sinoatrial (SA) node sets the inherent rate of contraction

Conducting System

Figure 18.12

Conduction System

Conduction System and ECGs

Conduction System of Heart

Disorders of the Heart

• Coronary artery disease

• Atherosclerosis – fatty deposits

• Angina pectoris – chest pain

• Myocardial infarction – blocked coronary artery

• Silent ischemia – no pain or warning

Disorders of the Heart

• Heart failure• Progressive weakening of the heart• Cannot meet the body’s demands for

oxygenated blood

• Congestive heart failure – heart enlarges• Pumping efficiency declines

• Cor pulmonale • Enlargement and potential failure of the right

ventricle

Disorders of Conduction

• Ventricular fibrillation

• Rapid, random firing of electrical impulses in the ventricles

• Atrial fibrillation

• Multiple waves of impulses randomly signal the AV node

• Signals ventricles to contract quickly and irregularly