Chapter 23 - Structure and Function of the Cardiovascular and Lymphatic Systems PDF

Chapter 23 Structure and Function of the Cardiovascular and Lymphatic Systems  Circulatory System  Heart Right heart Pulmonary circulation  Pumps blood through the lungs Left heart Systemic circulation ...

Chapter 23 Structure and Function of the Cardiovascular and Lymphatic Systems  Circulatory System  Heart Right heart Pulmonary circulation  Pumps blood through the lungs Left heart Systemic circulation  Pumps blood through the body Circulatory System (Cont.) From Patton, K.T., Thibodeau, G.A., & Douglas, M.M. (2012). Essentials of anatomy & physiology. Elsevier.  Circulatory System (Cont.)  Heart Mediastinum Heart wall Three layers enclosed in the pericardium  Epicardium – Outer layer  Myocardium – Composed of cardiac muscle  Endocardium – Inner lining  Circulatory System (Cont.)  Heart (cont.) Pericardium Pericardial sac Pericardial cavity Pericardial fluid  Heart Wall From Applegate, E. (2011). The anatomy and physiology learning system (4th ed.). Saunders.  Chambers of the Heart  Right atrium  Left atrium  Right ventricle  Left ventricle Structures of the Heart  Valves of the Heart  Atrioventricular valves: Tricuspid valve Mitral valve  Semilunar valves: Pulmonic semilunar valve Aortic semilunar valve Valves of the Heart (Cont.) From Naish, J. (2015). Medical sciences (2nd ed.). Saunders.  Great Vessels  Superior and inferior venae cavae  Pulmonary artery Right and left pulmonary arteries  Pulmonary veins  Aorta  Blood Flow and Cardiac Cycle  Cardiac cycle  Diastole  Systole  Phases of the cardiac cycle  Blood Flow and Cardiac Cycle (Cont.) Adapted from Patton, K.T., & Thibodeau, G.A. (2018). The human body in health and disease (7th ed.). Elsevier.  Blood Flow and Cardiac Cycle (Cont.) Adapted from Solomon, E. (2016). Introduction to human anatomy and physiology (4th ed.). Saunders. Normal Intracardiac Pressures Mean (mm Hg) Range (mm Hg) Right atrium 4 0–8 Right ventricle Systolic 24 15–28 End-diastolic 4 0–8 Left atrium 7 4–12 Left ventricle Systolic 130 90–140 End-diastolic 7 4–12  Coronary Vessels  Right coronary artery Conus Right marginal branch Posterior descending branch  Left coronary artery Left anterior descending artery Circumflex artery  Coronary Vessels (Cont.)  Collateral arteries  Coronary capillaries  Coronary veins: Coronary sinus Great cardiac vein Posterior vein of the left ventricle  Lymphatic vessels Coronary Vessels (Cont.) From Patton, K.T., & Thibodeau, G.A. (2018). The human body in health and disease (7th ed.). Elsevier. 1. Which of the following is an accurate statement regarding blood flow through the heart? A. Flows from the left ventricle through the bicuspid valve. B. Flows from the right atrium through the aortic valve to the right ventricle. C. Flows from the right ventricle through the pulmonic semilunar valve. D. Flows from the left atrium through the tricuspid valve to the left ventricle.  Structures That Control Heart Action  Cardiac action potentials  Conduction system Sinoatrial node (SA) Atrioventricular node (AV) Bundle of His (AV bundle) Right and left bundle branches Purkinje fibres Cardiac Conduction System From Koeppen, B.M. (Ed.). (2010). Berne & Levy physiology (6th ed.). Mosby.  Structures That Control Heart Action  Propagation of cardiac action potentials Resting membrane potential Depolarization Repolarization Hyperpolarization Refractory period  Electrocardiogram  Automaticity  Rhythmicity Electrocardiogram  Structures That Control Heart Action  Cardiac innervation Sympathetic nerves Parasympathetic nerves  Adrenergic receptor function β-Adrenergic receptors Norepinephrine or epinephrine  Myocardial Cells  Nearly identical to skeletal muscle cells Differences important for cardiac function  Sarcomeres  Intercalated discs  Actin, myosin, and the troponin–tropomyosin complex A band, I bands, Z line, M line Troponin T, I, and C  Myocardial metabolism Myocardial oxygen consumption  Myocardial Contraction and Relaxation  Cross-bridge theory of muscle contraction Excitation-contraction coupling  Calcium channel L-type (calcium channel blocker medications) T-type Myocardial Contraction and Relaxation (Cont.) Myocardial Contraction and Relaxation (Cont.)  Myocardial Contraction and Relaxation (Cont.) Adapted from Thibodeau, G.A., & Patton, K.T. (1999). Anatomy & physiology (4th ed.). Mosby. 2. Which statement is TRUE with regard to cardiac and skeletal muscle fibres? A. Cardiac fibres have fewer mitochondria than skeletal muscle fibres. B. Cardiac fibres are parallel, and skeletal muscle fibres are branched. C. Cardiac fibres have a slower transmission than skeletal muscle fibres. D. Cardiac fibres have only one nucleus, and skeletal muscle fibres have many nuclei.  Cardiac Performance  Cardiac output Preload Volume/pressure inside ventricle at end of diastole Left ventricular end-diastolic volume Laplace’s law Starling’s law of the heart Afterload Resistance to ejection of blood from left ventricle Load muscle must move after it starts to contract Determined by system vascular resistance in aorta  Cardiac Performance (Cont.)  Myocardial contractility Stroke volume and preload Inotropic agents Oxygen and carbon dioxide levels  Cardiac output Volume of blood flowing through either the systemic or pulmonary circuit in litres per minute  Ejection fraction Cardiac Output  Cardiac Performance  Heart rate Cardiovascular vasomotor control centre Excitatory and inhibitory centres Neural reflexes Baroreceptor reflexes Atrial receptors Brainbridge reflex Hormones and biochemicals  Systemic Circulation  Arteries  Arterioles  Capillaries  Venules  Veins  Structure of Blood Vessels  Lumen Tunica intima Tunica media Tunica externa (adventitia) Endothelium Structure of Blood Vessels From Patton, K.T., & Thibodeau, G.A. (2016). Structure & function of the body (15th ed.). Elsevier. Structure of Blood Vessels (Cont.)  Factors Affecting Blood Flow  Pressure Force exerted on a liquid per unit area  Resistance Opposition to force Diameter and length of the blood vessels contribute to resistance  Poiseuille’s law  Factors Affecting Blood Flow (Cont.)  Neural control of total peripheral resistance Change in diameter of the vessels Baroreceptors Arterial chemoreceptors Baroreceptor and Chemoreceptors Modified from Patton, K.T. (2019). Anatomy & physiology (10th ed.). Elsevier. Baroreceptor and Chemoreceptors Modified from Patton, K.T. (2019). Anatomy & physiology (10th ed.). Elsevier.  Factors Affecting Blood Flow  Velocity  Laminar versus turbulent flow  Vascular compliance Laminar and Turbulent Flow 3. A patient is diagnosed with increased systemic vascular resistance. What will be the effect on the heart? A. Left atrium will be required to pump harder. B. Right atrium chamber will become enlarged. C. Left ventricle will be required to pump harder. D. Right ventricle will become ineffective.  Regulation of Blood Pressure  Arterial pressure Mean arterial pressure (MAP)  Effects of cardiac output  Effects of total peripheral resistance  Effects of hormones Epinephrine and norepinephrine Antidiuretic hormone, renin-angiotensin-aldosterone system, and atrial natriuretic peptides  Regulation of Blood Pressure (Cont.)  Effects of other mediators Nitric oxide Adrenomedullin  Venous pressure Regulation of Blood Pressure (Cont.) Regulation of Coronary Circulation  Coronary perfusion pressure  Autoregulation  Autonomic regulation  Lymphatic System  Special vascular system that picks up excess fluid and returns it to the bloodstream  Lymphatic fluid lymph  Lymphatic veins and venules  Right lymphatic duct  Thoracic duct  Lymph nodes Afferent and efferent lymphatic vessels Lymphatic System (Cont.) From VanMeter, K.C., & Hubert, R.J. (2010). Microbiology for the healthcare professional. Mosby.