Cardiovascular System Structure & Circulation

Heart

System Includes Heart Blood Vessels Arteries – away from Veins – toward Capillaries

Heart

Cardiovascular Functions Transportation Carries: O2, CO2, nutrients, waste, enzymes Regulation pH Temperature Water balance Protection Blood loss - clotting Immune system

Cardiovascular Functions Ensures unidirectional flow of blood Pumps blood to lungs and body Develops blood pressure for nutrient and waste exchange

Heart-Anatomical Location and Orientation

Heart Anatomical Orientation and Location

Heart Structure

Heart Structure 4 Chambers: Right Atrium Receives blood from body: Low in oxygen Superior vena cava Arms and upper body Inferior vena cava Lower extremities

Heart Structure 4 Chambers: Right Ventricle Lower right chamber Low oxygen blood Send blood to lung for oxygenation

Heart Structure 4 Chambers: Left Atrium Receives blood from: Lungs Oxygenated blood Pumps to left ventricle

Heart Structure 4 Chambers: Left Ventricle Receives blood from left atrium – high oxygen Pumps to body circulation (systemic)

Blood Flow Through the Heart

Blood Flow Through the Heart Animation https://www.youtube.com/watch?v=Rj_qD0SEGG k

Heart Structure Pericardium “Sac” around heart Made of serous membrane Facts Room to move Reduces friction Confines heart Problems Pericarditis Pericardial Effusion

Pericardium

Layers of the Heart

Layers of the Heart Epicardium Myocardium Endocardium Figure 18.3

Cardiac Muscle Cells

Cardiac Muscle Cells

Heart Structure

Heart Structure Endocardium Inner membrane - lines heart Endocarditis – endocardium inflammation

Heart Structure Myocardium Heart Muscle Surrounds chambers Thickness varies L. ventricle > R. ventricle > R. atrium > L. atrium

Heart Structure Epicardium Membrane on outside of the heart

Valves of the Heart

Heart Valves

Heart Valves Flow in one direction Prevents backflow Made of collagen connective tissue

Heart Valves 2 Atrioventricular valves – (AV) Bicuspid (2 flaps) Tricuspid (3 flaps) Bicuspid (2 flaps) AKA Mitral Valve Attachment: Papillary muscles, prevent blood reflux

Atrioventricular Valves (Open)

Atrioventricular Valves (Closed) Figure 18.9b

Heart Valves 2 Semilunar valves Composition: connective tissue flaps with crescent-shapes Pulmonary: stop reflux in right ventricle Aortic: stop reflux in left ventricle

Semilunar Valves (Open vs Closed)

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

Conduction System

Conduction System

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