ORGANIZATION OF CARDIOVASCULAR SYSTEM 1 HEART 2 BLOOD

ORGANIZATION OF CARDIOVASCULAR SYSTEM 1. HEART 2. BLOOD VESSELS A. ARTERIES B. VEINS 3. CAPILLARIES

Lungs Pulmonary capillaries Pulmonary arteries Systemic veins Right side of heart Systemic circulation = O 2 -rich blood Organ systems = O 2 -poor blood Pulmonary veins Pulmonary circulation Left side of heart Systemic arteries Systemic capillaries Fig. 9 -1, p. 242

MAIN FUNCTIONS OF THE CIRCULATORY SYSTEM Transport and distribute essential substances to the tissues. Remove metabolic byproducts. Adjustment of oxygen and nutrient supply in different physiologic states. Regulation of body temperature. Humoral communication.

Distribution of Blood in the Circulatory System 67% IN THE SYST. VEINS/VENULES • 5% IN THE SYSTEMIC CAPILLARIES • 11% IN THE SYSTEMIC ARTERIES • 5% IN PULMONARY VEINS • 3% IN PULMONARY ARTERIES • 4% IN PULMONARY CAPILLARIES • 5% IN HEART ATRIA/VENTRICLES •

Superior vena cava (from head) Aorta Left pulmonary artery Right pulmonary artery Left pulmonary vein Right pulmonary vein Left atrium Pulmonary semilunar valve Left atrioventricular (AV) valve Right atrium Right atrioventricular (AV) valve Aortic semilunar valve Inferior vena cava (from body) Left ventricle Interventricular septum Right ventricle Arrows indicate direction of the blood flow. = O 2 -rich blood = O 2 -poor blood Fig. 9 -2 a, p. 243

Aorta Pulmonary artery Superior vena cava Pulmonary valve Pulmonary veins Right atrium Right AV valve Right ventricle Left atrium Left AV valve Aortic valve Chordae tendineae Papillary muscle Left ventricle Interventricular septum Inferior vena cava Fig. 9 -4 a, p. 245

Pressure Drop in the Vascular System ELASTIC TISSUE MUSCLE MEAN PRESSURE LARGE ARTERIES LARGE SMALL ARTERIES ARTERIOLES CAPILLARIES VENULES &VEINS SMALL INSIDE DIAMETER LARGE