The Cardiovascular System 11 The Cardiovascular System

c) When valves are open and closed: Heart Valves … c) When valves are open and closed: i) Heart is filling with blood when: AV valves: Semilunar valves: ii) Heart Pumping = Ventricles contract: iii) Valves operate opposite of one another Bicuspid Pulmonary S Aortic S Tricuspid Anterior View

7. Blood Vessels Attached To Heart Pulmonary Trunk a) Arteries i) *Aorta *Blood enters Aorta from: *Takes blood to: ii) Pulmonary Trunk and Pulmonary Arteries (2) *Blood enters P Trunk from: Pulmonary Trunk  L and R Pulmonary A. *Pulmonary Arteries take blood to: Aorta

Associated Great Vessels … b) Veins i) Superior Vena Cava Blood returns from: and goes to: ii) Inferior Venae Cava And goes to: iii) Pulmonary veins (4)

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

8. Blood Vessels that serve the Cardiac Muscle a. Arteries i) *Coronary arteries: *Branch from: *Oxygen content: b. Veins i) Cardiac veins: Empty blood to: Oxygen content: ii) Coronary sinus: Coronary Sinus empties blood to:

8. Blood Flow Through the Heart Superior & Inferior Vena Cava  RA RA  tricuspid valve  RV RV  pulmonary semilunar valve  Pulmonary Trunk Pulmonary Trunk  Right and Left Pulmonary Arteries  Lungs AORTA LPA RPA SV PV LA RA RV LV IV

Lungs  Pulmonary veins  LA AORTA Lungs  Pulmonary veins  LA LA  Bicuspid Valve  LV LV  Aortic Semilunar Valve  Aorta Aorta  body cells SV PA LPV LA RPV RA LV RV IV

Figure 11.4 Capillary beds of lungs where gas exchange occurs Pulmonary Circuit Pulmonary arteries Pulmonary veins Venae cavae Aorta and branches Left atrium Left ventricle Right atrium Heart Right ventricle Systemic Circuit Capillary beds of all body tissues where gas exchange occurs KEY: Oxygen-rich, CO2-poor blood Oxygen-poor, CO2-rich blood Figure 11.4

AORTA SV PA PV LA RA LV RV IV

C. Heart Physiology 1. The Conduction System of the Heart = autorhythmic cardiac cells + special conductive tissue a) Autorhythmic cells

The Heart: Conduction System … b) Special tissue Sinoatrial node = SA node (“pacemaker) Function Atrioventricular node = AV node,

Atrioventricular bundle = AV bundle Function Bundle branches Conduction System … Atrioventricular bundle = AV bundle Function Bundle branches Purkinje fibers

Superior vena cava Sinoatrial (SA) node (pacemaker) Left atrium Atrioventricular (AV) node Right atrium Atrioventricular (AV) bundle (bundle of His) Bundle branches Purkinje fibers Purkinje fibers Interventricular septum Figure 11.7

c) EKG & Heart Contraction Disorders Normal EKG P QRS T MilliVolts P QRS T Time Electrocardiogram

Abnormal Rhythums Heart Block SA node dysfunction Fibrillation Cardiac Arrest Tachycardia— Bradycardia—

2. The Heart: Cardiac Cycle & Heart Sounds Cardiac cycle = events of one complete heart beat BASICS Atria contract simultaneously Atria relax, then ventricles contract Systole = contraction Diastole = relaxation

3. The Heart: Cardiac Output Heart rate (HR) = beats per minute: 75 Stroke volume (SV) = Volume of blood pumped by a ventricle in one contraction = 70 mL Cardiac output (CO) Amount of blood pumped by each ventricle per minute = 5,250 ml/min = 5.250 Liters/minute

4. The Heart: Regulation of Heart Rate Nervous System & Endocrine System Raise HR when: and if blood volume or pressure is low Hormones Epinephrine Thyroxine Lower HR when:

II. Blood Vessels (Vascular System) Introduction: General Functions and Anatomy: 1. General Function Arteries Arterioles Veins Venules Capillaries