The Cardiovascular System Chapter 13 Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Introduction Cardiovascular system distributes blood Pump (heart) Distribution areas (capillaries) Heart has 4 compartments 2 receive blood (atria) 2 pump blood out (ventricles) Vessels Veins return blood to the heart Arteries take blood away from the heart Human Anatomy, 3rd edition Prentice Hall, © 2001

Superficial Anatomy of the Heart Atria = “entrance ways” Thin-walled Upper chambers Ventricles = “hollow spaces” Thick, muscular Apex points down & tips slightly to the left Base is superior Great vessels attach Human Anatomy, 3rd edition Prentice Hall, © 2001

The Coverings of the Heart Pericardium = “around the heart” Visceral pericardium = epicardium Parietal pericardium Pericardial space contains pericardial fluid Human Anatomy, 3rd edition Prentice Hall, © 2001

Internal Anatomy of the Heart Chambers of the heart Right & left atrium Separated by the interatrial septum Right & left ventricle Separated by the interventricular septum Human Anatomy, 3rd edition Prentice Hall, © 2001

Structure of the Heart Wall Epicardium = “upon the heart” = visceral pericardium Dense fibrous connective tissue Myocardium is the middle layer Cardiac muscle Endocardium = “inside the heart” Simple squamous epithelium Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Great Vessels Superior & inferior vena cava Return blood from body to right atrium Coronary Sinus Returns blood from heart wall to right atrium Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Great Vessels Pulmonary veins Return blood (oxygenated) from lungs to left atrium Aorta Takes blood from left ventricle to body Pulmonary artery Takes blood (deoxygenated) from right ventricle to lungs Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Valves of the Heart Atrioventricular (AV) valves separate the atria from the ventricles Tricuspid valve – right Bicuspid valve (mitral) – left Semilunar valves separate the ventricles from the great vessels Pulmonary semilunar valve Aortic semilunar valve Heart sounds Human Anatomy, 3rd edition Prentice Hall, © 2001

Valves of the Heart (Ventricular Diastole) FG21_07A.JPG Title: Valves of the Heart Notes: (a)Valve position during ventricular diastole; AV valves open, semilunar valves closed. (b)Cardiac valves during ventricular systole; AV valves closed, semilunar valves open. Note how chordae tendineae and papillary muscles affect movement of AV valve. Keywords: heart, valves, ventricular systole, tricuspid, fibrous skeleton, mitral valve, aortic semilunar, pulmonary semilunar, chordae tendineae, ventricle, papillary muscles Human Anatomy, 3rd edition Prentice Hall, © 2001

Valves of the Heart (Ventricular Systole) FG21_07B.JPG Title: Valves of the Heart Notes: (c)Superior view of heart valves. (d)Proper placement of a stethoscope varies depending on which heart sounds and valves are of interest. Keywords: heart, valves, pulmonary valve, aortic valve, mitral, atrium, vena cava, aorta, pulmonary trunk, heart sounds, stethoscope, aortic semilunar, pulmonary semilunar, mitral, tricuspid Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Coronary Circulation Vessels that supply the myocardium itself Right coronary artery Left coronary artery Cardiac veins Human Anatomy, 3rd edition Prentice Hall, © 2001

Cast of Coronary Vessels FG21_09C.JPG Title: Coronary Circulation Notes: (a)Vessels supplying anterior surface of heart. (b)Coronary vessels supplying posterior surface of heart. (c)Cast of coronary vessels. (d)Coronary angiogram, left lateral projection. Keywords: coronary, circulation, anterior, artery, vein, circumflex branch, anterior interventricular branch, great cardiac vein, marginal branch, posterior interventricular branch, middle cardiac vein, right coronary artery, small cardiac vein, coronary sinus Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Cardiac Cycle Contraction pattern of the myocardium Determined by the conduction system Systole = contraction Diastole = relaxation Both atria contract Both ventricles contract Atria alternate with ventricles Human Anatomy, 3rd edition Prentice Hall, © 2001

Conduction System of the Heart The average heart rate is 72 beats/min. Depolarization stimulates contraction Human Anatomy, 3rd edition Prentice Hall, © 2001

Conducting System of the Heart Depolarization begins in the sinoatrial (SA) node Pacemaker FG21_12B.JPG Title: The Conducting System of the Heart Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction. Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers Human Anatomy, 3rd edition Prentice Hall, © 2001

Conduction System of the Heart Depolarization spreads through atria, atria contract FG21_12C.JPG Title: The Conducting System of the Heart Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction. Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers

Conducting System of the Heart Atrioventricular (AV node) depolarizes Depolarization travels down the AV bundle (bundle of His) FG21_12E.JPG Title: The Conducting System of the Heart Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction. Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers Human Anatomy, 3rd edition Prentice Hall, © 2001

Conducting System of the Heart Depolarization spreads up the ventricular walls via Purkinje fibers. Ventricles contract FG21_12F.JPG Title: The Conducting System of the Heart Notes: (a)The stimulus for contraction is generated by pacemaker cells at the SA node.(b)Movement of the contractile stimulus: SA node, AV node, atrial contraction, AV bundle and bundle branches, Purkinjie fibers, ventricular myocardium, ventricular contraction. Keywords: heart, conducting system, sinoatrial node, SA, atrioventricular, AV, AV bundle, bundle branch, Purkinje fibers Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Electrocardiogram ECG = a recording of electrical events in the heart P wave = atrial depolarization QRS wave = ventricular depolarization T wave = ventricular repolarization Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Electrocardiogram FG21_13A.JPG Title: An Electrocardiogram Notes: An ECG printout is a strip of graph paper containing a record of the electrical events monitored by electrodes attached to the body surface. The enlarged section indicates the major components of the ECG. Keywords: electrocardiogram, ECG, electrical events, electrodes, P wave, T wave, QRS complex, atria, ventricles, contract Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Electrocardiogram FG21_13B.JPG Title: An Electrocardiogram Notes: An ECG printout is a strip of graph paper containing a record of the electrical events monitored by electrodes attached to the body surface. The enlarged section indicates the major components of the ECG. Keywords: electrocardiogram, ECG, electrical events, electrodes, P wave, T wave, QRS complex, atria, ventricles, contract Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Disorders Abnormal heart rates Bradycardia Tachycardia Fibrillation Angina pectoris Myocardial infarction Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Blood Vessels Human Anatomy, 3rd edition Prentice Hall, © 2001

Functions of Blood Vessels Carry blood away from the heart - arteries Transport blood to tissues - capillaries Return blood to the heart – veins Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Walls of Blood Vessels 3 layers Inner layer is endothelium = tunica intima Simple squamous epithelium Middle layer = tunica media Smooth muscle Outer layer = tunica externa Dense fibrous connective tissue Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Atherosclerosis Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Arteries Elastic arteries Large Muscular arteries Medium-sized Arterioles Very small Capable of vasoconstriction and vasodilation Human Anatomy, 3rd edition Prentice Hall, © 2001

Systemic Arterial System FG22_10.JPG Title: An Overview of the Systemic Arterial System Notes: Figure 22-10 is an overview of the arterial system. This figure indicates the relative locations of major systemic arteries. Keywords: arterial system, systemic, carotid, aorta, subclavian, axillary, renal, mesenteric, iliac, femoral, genicular, popliteal, brachial, celiac, brachiocephalic, vertebral, palmar, plantar Human Anatomy, 3rd edition Prentice Hall, © 2001

Major Arteries of the Trunk FG22_16.JPG Title: Major Arteries of the Trunk Notes: Diagrammatic view of the major arteries of the trunk. Keywords: arteries, trunk, abdominal aorta, gonadal, mesenteric, splenic, gastric, celiac, phrenic, hepatic, suprarenal, renal, lumbar, iliac, thoracic aorta, pericardials, esophageals, bronchials, mediastinals, intercostals, subclavian, vertebral thyrocervical Human Anatomy, 3rd edition Prentice Hall, © 2001

Arteries of the Chest and Upper Extremity FG22_12A.JPG Title: Arteries of the Chest and Upper Extremity Notes: (a) Arteries originating along the aortic arch shown branching into the chest and upper arm. (b)Anterior view of forearm. (c)Anterior view of axillary region. (d)Flow chart showing arterial distribution from the aortic arch. Keywords: arteries, chest, upper extremity, aortic arch, carotid, brachiocephalic, ascending, descending, thoracic, abdominal, ulnar, brachial, subscapular, brachial, humeral, thyrocervical, vertebral, suprascapular, axillary, intercostals, radial, palmar Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Capillaries All blood-tissue exchange occurs here Tissue = tunica intima only Human Anatomy, 3rd edition Prentice Hall, © 2001

Capillary Bed with Precapillary Sphincters Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Veins Venules Very small Contain only tunica intima and tunica externa Medium-sized veins and large veins Contain same 3 layers as arteries Tunica media thinner Tuna externa - thickest layer Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Veins with Valves Some veins contain valves – prevent blood from flowing backwards Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Varicose Veins www.sirweb.org/patPub/varicoseVeinMain.shtml www.veinhelp.com/varicoseVeins.htm Human Anatomy, 3rd edition Prentice Hall, © 2001

Systemic Venous System FG22_21.JPG Title: An Overview of the Systemic Venous System Notes: All of the systemic veins (except the cardiac veins) drain into either the superior vena cava or the inferior vena cava. The superior vena cava (SVC) receives blood from the tissues and organs of the head, neck, chest, shoulders, and upper extremities. Keywords: systemic venous system, overview, jugular, vertebral, subclavian, axillary, cephalic, brachial, basilic, hepatic, cubital, radial, antebrachial, ulnar, palmar, digital, saphenous, popliteal, peroneal, tibial, plantar, femoral, iliac, lumbar, gonadal Human Anatomy, 3rd edition Prentice Hall, © 2001

Venous System of the Trunk and Upper Limb FG22_23.JPG Title: The Venous Drainage of the Trunk and Upper Limb Notes: A diagrammatic view of the venous drainage of the trunk and upper limb. Keywords: venous drainage, upper extremities, chest, abdomen, vertebral, jugular, subclavian, brachiocephalic, vena cava, axillary, cephalic, hemiazygos, brachial, basilic, phrenics, suprarenals, radial, iliac, lumbars, gonadals, renals, hepatics, mediastinals Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Blood Flow Blood flows because of different pressures in the system Mean pressure in aorta = 100 mmHg Pressure decreases continuously through arterial and venous system Arteries = 100 – 40 mmHg Arterioles = 40 – 25 mmHg Capillaries = 25 – 12 mmHg Venules = 12 – 8 mmHg Veins = 8 – 5 mmHg Vena cava = 2 mmHg Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Blood Pressure Definition – force exerted by blood on the wall of any blood vessel Clinical use – refers to pressure in the arteries Ventricles contract (systole) Arterial pressure rises Systolic pressure Ventricles relax (diastole) Arterial pressure drops Diastolic pressure Average blood pressure 120/80 (young male) 110/70 (young female) Hypertension Human Anatomy, 3rd edition Prentice Hall, © 2001