Porth's Essentials of Pathophysiology, 4e

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Circulatory Function

T Control of Cardiovascular Function 17 C h a p t e r he main function of the cardiovascular or circulatory system, which consists of the heart and blood ves- sels, is transport. The circulatory system transports and distributes oxygen and nutrients needed for metabolic processes to the tissues, carries waste products from cellular metabolism to the kidneys and other excretory organs for elimination, and circulates fluids, electro- lytes, and hormones needed to regulate body function. This process is carried out with exquisite precision so that oxygen and nutrient delivery is exactly matched to meet tissue needs. Organization of the Circulatory System The circulatory system can be divided into two parts: the pulmonary (or central ) circulation, which moves blood through the lungs and creates a link with the gas exchange function of the respiratory system, and the systemic (or peripheral ) circulation , which moves blood throughout all the other tissues of the body (Fig. 17-1). Pulmonary and Systemic Circulations The pulmonary circulation consists of the right side of the heart, the pulmonary arteries and arterioles, the pulmonary capillaries, and the pulmonary veins. The large pulmonary vessels are unique in that the

Organization of the Circulatory System Pulmonary and Systemic Circulations Volume and Pressure Distribution Principles of Blood Flow Pressure, Resistance, and Flow Flow in Series and Parallel Vessels Velocity, Cross-Sectional Area, and Flow Laminar Versus Turbulent Flow Wall Tension, Radius, and Pressure Vascular Distensibility The Heart as a Pump Functional Anatomy of the Heart Pericardium Myocardium Endocardium Heart Valves and Fibrous Skeleton Electrical Activity of the Heart Cardiac Conduction System Action Potentials Absolute and Relative Refractory Periods Arrhythmias and Conduction Disorders Electrocardiography Cardiac Cycle Ventricular Systole and Diastole Atrial Filling and Contraction Regulation of Cardiac Performance Preload Afterload Cardiac Contractility Heart Rate The Systemic Circulation and Control of Blood Flow Blood Vessels

Arterial System Venous System Capillaries Lymphatic System The Microcirculation

Autoregulation of Blood Flow Endothelial Control of Blood Flow Humoral Control of Blood Flow Collateral Circulation Neural Control of Blood Flow

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