 A closed system of the heart and blood vessels › The heart pumps blood › Blood vessels allow blood to circulate to all parts of the body  The functions of the cardiovascular system › To deliver oxygen and nutrients to cells and tissues › To remove carbon dioxide and other waste products from cells and tissues

© 2012 Pearson Education, Inc. Figure 11.1c Superior vena cava Pulmonary trunk Diaphragm (c) Aorta Left lung Pericardium (cut) Apex of heart Parietal pleura (cut)

Figure 11.3a Left common carotid artery Left subclavian artery Aortic arch Ligamentum arteriosum Left pulmonary artery Left pulmonary veins Left atrium Auricle of left atrium Circumflex artery Left coronary artery in coronary sulcus (left atrioventricular groove) Left ventricle Great cardiac vein Anterior interventricular artery (in anterior interventricular sulcus) Apex Brachiocephalic trunk Superior vena cava Right pulmonary artery Ascending aorta Pulmonary trunk Right pulmonary veins Right atrium Right coronary artery in coronary sulcus (right atrioventricular groove) Anterior cardiac vein Right ventricle Marginal artery Small cardiac vein Inferior vena cava (a)

 Arthropods have open system  Humans have closed system

 Left atria to Aorta to arteries to arterioles to capillaries for gas/nutrient exchange  De-oxygenated blood travels through venules to veins to superior/inferior vena cava to right atrium of heart.  Superior and inferior vena cava feed the rt. Atrium.

 Blood moves from rt. Atrium to rt. Ventricle through the tricuspid valve.  Blood is pumped from the rt. Ventricle through the pulmonary semilunar valve to the pulmonary (trunk) artery to the lungs  Gas exchange occurs in alveoli

© 2012 Pearson Education, Inc. Figure 11.3b Superior vena cava Right atrium Right pulmonary veins Fossa ovalis Right atrioventricular valve (tricuspid valve) Right ventricle Chordae tendineae Inferior vena cava (b) Frontal section showing interior chambers and valves. Aorta Left pulmonary artery Left atrium Left pulmonary veins Pulmonary semilunar valve Left atrioventricular valve (bicuspid valve) Aortic semilunar valve Left ventricle Interventricular septum Myocardium Visceral pericardium Right pulmonary artery

Figure 11.4 Capillary beds of lungs where gas exchange occurs Pulmonary veins Aorta and branches Left atrium Left ventricle Heart Systemic Circuit Right atrium Right ventricle Venae cavae Pulmonary arteries Pulmonary Circuit Capillary beds of all body tissues where gas exchange occurs KEY: Oxygen-rich, CO 2 -poor blood Oxygen-poor, CO 2 -rich blood

 Characterizes human homeostasis  Endothermic animals regulate body temperature  Arteries carry warm blood from core to body, veins carry cold blood from body.  The vessels run next to each other – counter-current exchange

 72 beats per min.  Beat begins in the right atrium at the sinoatrial node (“pacemaker”)  Then to the atrioventricular node  Then to the bundle of His and Purkinje Fibers in the ventricles causing contractions  Systole – during contraction  Diastole - relaxation

© 2012 Pearson Education, Inc. Figure 11.7 Superior vena cava Sinoatrial (SA) node (pacemaker) Atrioventricular (AV) node Right atrium Bundle branches Purkinje fibers Left atrium Atrioventricular (AV) bundle (bundle of His) Purkinje fibers Interventricular septum

 Plasma and cells  3 types of cells 1. Red blood cells – erythrocytes – carry oxygen 2. White blood cells – leukocytes – fight infection 3. Platelets – clotting cells

 When a blood vessel is damaged, the platelets stick to the vessel wall and send signals  Platlets release protein clotting factors that signal a series of reactions  Prothrobin activator converts prothrombin to thrombin  Thrombin converts fibrinogen to fibrin threads – this strengthens the clot and stops bleeding

© 2012 Pearson Education, Inc. Figure 10.6, step 1 Step Vascular spasms occur. 1 Smooth muscle contracts, causing vasoconstriction.

© 2012 Pearson Education, Inc. Figure 10.6, step 2 Step Platelet plug forms. Injury to lining of vessel exposes collagen fibers; platelets adhere. Platelets release chemicals that make nearby platelets sticky; platelet plug forms. Collagen fibers Platelets 2

© 2012 Pearson Education, Inc. Figure 10.6, step 3 Fibrin Step Coagulation events occur. 3 Fibrin forms a mesh that traps red blood cells and platelets, forming the clot. Clotting factors present in plasma and released by injured tissue cells interact with Ca 2+ to form thrombin, the enzyme that catalyzes joining of fibrinogen molecules in plasma to fibrin.

 This is where the blood is made  Located in the center of bone