Clinical Anatomy of the Heart PDF

Clinical Anatomy of the Heart Physician Associates Dr Huda AL-nhas [email protected]  Learning Objectives Name and identify the heart chambers, valves, and great vessels. Describe the pathway of blood flow through the heart. Name and state the position, str...

Clinical Anatomy of the Heart Physician Associates Dr Huda AL-nhas [email protected]  Learning Objectives Name and identify the heart chambers, valves, and great vessels. Describe the pathway of blood flow through the heart. Name and state the position, structure and function of each of the heart valves. Discuss the role and structure of the heart's fibrous skeleton. Describe the arrangement of the fibrous and serous pericardium and the structure of the heart wall. Provide an overview of systemic and pulmonary circulation. Name and identify the vessels of the coronary circulation. Understand the regulation of cardiac activity. Provide an overview of foetal circulation and the changes that occur at birth. Explain clinical conditions related to heart anatomy.  Heart Cone shaped, muscular organ. Bas e Pumping blood by repeated rhythmic contractions. Size of a fist, ~300 grams, 11cm long. Located in the mediastinum, protected by the ribs and sternum. Lies between ribs 2-5 to the left of the Ape x midline. Apex lies in the 5th intercostal space in the. midclavicular line. Anatomy of the Heart Chambers of the heart Left 4 atriu champers m Right (LA) Divisions: atriu The heart is divided m longitudinally into right and left (RA) Interatrial septum sides by the: atrioventricular valves Interatrial septum (between the atria) Right Left ventri ventri Interventricular septum (between cle cle the ventricles) (RV) (LV) It Interventricular septum is divided horizontally into upper and lower sections by the atrioventricular valves.  Heart valves A fold of endocardium with the connective tissue in between. One-way valves that prevent backflow of blood Located at the entrance and the exit of each 4 valves: ventricle. 2 Atrioventricular (AV) valves (entrance) Semilunar (SL) valves 2 Semilunar (SL) valves (exit) Atrioventricular (AV) valves Atrioventricular (AV) 2 AV valves located between the atria and valves ventricles: - - Tricuspid (right AV valve): 3 cusps Bicuspid/mitral (left AV valve): 2 T cusps M Opened by the blood flowing from atria to the ventricles. Closed when the ventricles contract. Held by chordae tendinae, which attached to papillary muscles. Contraction of papillary muscles prevents eversion of the valves and therefore backflow of blood into the atria. The closing – Mitral of the valve: AV at Heard valves (tricuspid the apex and mitral) (5th intercostal produces S1 ("Lub"): space, midclavicular line). – Tricuspid valve: Heard at the left lower sternal border (4th SUPERIOR VIEW intercostal space). Mitral valve Tricuspid valve Chordae tendinae Mitral valve Tricuspid valve Papillary muscle 2 cusps 3 cusps  Semilunar Valves 2 AV valves located between the ventricles and major vessels to guard the exit : - Pulmonary valve: 3 cusps - Aortic valve: 3 cusps Opened by the force of blood as the ventricles contract. Blood flows backwards in the aorta and pulmonary trunk during ventricular relaxation, this pools in the cusps and pushes them shut. Prevent backflow of blood into the ventricles. The closing of the semilunar valves produces S2 ("Dub"): – Aortic valve: Right 2nd intercostal space, near sternum. – Pulmonary valve: Left 2nd intercostal space, near sternum. Pulmonary valve Aortic valve 3 cusps 3 cusps A P  Heart Superior Valves Pulmonary & Aort vena a trunkarterie cava Pulmonary s veins RA LA Inferior vena cava Tricuspid (right AV) valv Bicuspid (mitral/left e AV) valve Pulmonary Aortic semilunar semiluna valve r valve RV LV Fibrous Skeleton of the Dense connective tissue structure that lies between the atria and Heart ventricles, corresponding to the atrioventricular groove and orifices. Components: circular fibrous rings (surround the 4 heart valves) that interconnected by fibrous tissue. Functions:  Central support: provides a stable framework for the heart's structure.  Prevents overdilation: limits the excessive dilation of valve openings.  Maintains valve competency: ensures the proper functioning of the valves.  Attachment Points:  Heart valves  Cardiac muscle fibbers of the atria and ventricles  Membranous part of the interventricular septum  Electrical Insulator: blocks the direct passage of electrical impulses from the atria to the ventricles, maintaining synchronized heart contractions. Heart wall Made up of three layers: Endocardium: inner layer – endothelium Myocardium: middle layer - cardiac muscle Pericardium: outer layer Pericardiu m Pericardium A fibro-serous sac that surrounds the heart and the roots of the great vessels, consisting of two main layers: 1. Fibrous Pericardium: Inelastic, composed of dense connective tissue. Fuses inferiorly with the diaphragm and superiorly with the great vessels. Functions: prevents overfilling of the heart and holds it in position. 2. Serous Pericardium: A double-layered structure with pericardial fluid in between. Parietal Layer: Lines the inner surface of the fibrous pericardium. Serous Layer Visceral Layer (Epicardium): Adheres closely to the surface of the heart. Function: Prevents friction during heart movement. Pericardium Heart wall Made up of three layers: Endocardium: inner layer – endothelium Myocardium: middle layer - cardiac muscle Pericardium: outer layer- visceral pericardium Visceral pericardium  Ventricular walls SUPERIOR VIEW Righ Lef t t The wall of the left ventricle is much thicker than that of the right ventricle  Great Aort Superior vena cava vessels Pulmonary es a arteri trunk & Pulmonary veins R L Inferior vena A A cava R L V V  Anterior View of the Heart Arch of aorta Superior vena Left pulmonary cava Ascending artery aorta Pulmonary trunk Auricle of left atrium Right atrium Left ventricle Right ventricle Ape x  Internal View of Heart Left Right atrium atrium Mitral valve Tricuspid Left valve ventricle Right ventricle Trabeculae Interventricular carnae septum Pectinate muscles – not  Blood flow through the Pulmonary arteries to lungs heart Aorta to systemic Pulmonary veinscirculation from IVC & SVC lungs from systemic circulation L R A A Tricuspid Bicuspid valve valve Aortic Pulmonary valve valve R L V V Circulatory System 1.Pulmonary Circulation (blue): 1. Involves the right side of the heart and the lungs. 2. Deoxygenated blood is pumped from the right heart to the lungs where it is oxygenated. 2.Systemic Circulation (red): 1. Involves the left side of the heart and the body. 2. Oxygenated blood is pumped from the left heart to the organs and tissues of the body to deliver oxygen and nutrients. Coronary Circulation Flow of blood through the coronary arteries, which supply the heart Coronary muscle with oxygen and nutrients, arteries and through the cardiac veins, which remove waste products by Cardia c veins draining into the heart. Coronary Arteries Coronary arteries arise from the cusps of the aortic valves at the root of the aorta. The heart receives approximately 250 ml/min of LCA Circumflex artery blood, delivered to the myocardium during ventricular relaxation (diastole). Main Branches: RCA 1. Right Coronary Artery (RCA): Marginal artery or acute Marginal artery Posterior interventricular Margina l artery or Posterior 2. Left Coronary Artery (LCA): artery Descending Artery (PDA) Anterior interventricular artery Posterior interventricular artery Anterior interventricular artery or Left anterior descending artery (LAD) anterior view Cardiac Veins The great, middle and small cardiac veins drain into the coronary sinus which empties into the right atrium. The anteriorAnterior cardiac veins drain directly into the right atrium view of heart Posterior view of heart Coronary sinus Great cardiac vein Anterior cardiac Middle cardiac Small cardiac veins vein  Coronary Angiography The patency of the coronary vessels can be examined by angiography (Angiogram) 00 50 0 1st 3rd NORMA RESTRICTED L Regulation of cardiac activity 1. Conduction system of the heart 2. Autonomic nervous system (ANS) Sympathetic fibres Parasympathetic fibres Visceral afferent fibres Conduction system of the heart Consists of non-contractile cells that initiate electrical -impulses Sinoatrial (SA) node - Atrioventricular (AV) node - AV bundle (bundle of His) - Right & left bundle AV node branches AV - Purkinje fibres node Fibrous Skeleton of AV the Heart: Electrical bundle Insulator: blocks the direct passage of bundle electrical impulses from branches the atria to the Purkinje ventricles, maintaining fibres synchronized heart Conduction system of the heart Autonomic nervous system (ANS) Sympathetic fibres Parasympathetic fibres Conduction system of the heart- Sympathetic Increase heart rat Sympathetic Increase force of contraction Dilate coronary vessels Cardiac Conduction system of the heart- Parasympathetic Parasympathetic Decrease heart rat Decrease force of contraction  Vagus nerve (CN X) Cardiac plexus Connection between the ANS and conduction system of the heart ANS Vagus nerve- Parasympathetic fibres Conduction system Cardiac plexus- Sympathetic Visceral sensory Afferent fibres parallel to the vagus nerve sense changes in blood oxygen, carbon dioxide, and pH levels, and regulate cardiac reflexes Afferent fibres parallel to the sympathetic fibres sense ischemia and tissue damage What happened when the heart suffers damage (e.g., ischemia) Referred pain Regulation of cardiac activity 1. Conduction system of the heart Sinoatrial (SA) node Atrioventricular (AV) node AV bundle (bundle of His) Right & left bundle branches Purkinje fibres 2.Autonomic nervous system (ANS) Sympathetic fibres Arise from lower 3 cervical and upper 4 sympathetic chain ganglia Increase heart rate & force of contraction, dilate coronary vessels Parasympathetic fibres Arise from vagus nerve Decrease heart rate Visceral afferent fibres Travel with sympathetic fibres to spinal cord at levels C6-8 &T1- 4 Referred pain is perceived in neck, upper limb and chest Cardiac plexus - located between the aortic arch (anteriorly) and Foetal Circulation Different from usual circulation because Oxygen and nutrients are received from the placenta via the umbilical vein Need to bypass non-functional lungs, intestine and liver. Foetal Circulation Ductus Foramen arteriosus Three circulatory shortcuts ovale 1. Foramen ovale connects the right to the left atria - bypassing right Ductus ventricle and pulmonary venosus system. Umbilic al vein 2. Ductus arteriosus connects the pulmonary bypassing trunk to pulmonary arch system of andaorta left –side of heart. Umbilical arteries 3. Ductus venosus connects the Placent umbilical vein to inferior vena a cava - bypasses the liver. Foetal circulation Pulmonary trunk Ductus arteriosus Aort SV C a Foram IV en oval e C L R A A R L V V  Changes at birthNewborn takes 1 st breath Lungs Umbilic expand LA al pressure cord Blood rushes into Foramen tied Umbilica ovale l vessels pulmonary closes to close circulation become O2 levels fossa rise ovalis Ductus venosus fibroses Constricts ductus arteriosus  Summary of changes Foetus Adult Ductus Ligamentu venosus m venosum Foramen Fossa ovalis ovale Ductus Ligamentu m arterios arteriosu us m  Clinical Correlations Component Associated Disease Valves Mitral valve prolapse, Tricuspid valve stenosis, Pulmonary valve stenosis, Aortic valve stenosis Myocardium Heart failure, Myocarditis, Myocardial infarction, Hypertrophic cardiomyopathy, Dilated cardiomyopathy Pericardium Pericarditis, Pericardial effusion, Cardiac tamponade, Constrictive pericarditis Conduction System Arrhythmias, Heart block, Congenital conduction defects, Atrial fibrillation, Ventricular fibrillation Coronary Arteries Coronary artery disease (CAD), Myocardial infarction (MI), Angina, Coronary artery aneurysm Aorta and Great Vessels Aortic aneurysm, Aortic dissection, Coarctation of the aorta, Atherosclerosis Pulmonary Arteries Pulmonary embolism, Pulmonary hypertension Pulmonary Veins Pulmonary venous congestion, Pulmonary venous obstruction, Pulmonary hypertension Chambers of the Heart (Atria Atrial fibrillation, Atrial septal defect, Ventricular septal defect, Congestive heart failure (CHF) and Ventricles) Ventricular Septum Ventricular septal defect (VSD), Myocardial infarction involving the septum, Hypertrophic cardiomyopathy Veins (e.g., coronary veins) Coronary sinus thrombosis, Venous insufficiency, Varicose veins, Deep vein thrombosis (DVT) Pericardial Cavity Pericardial effusion, Cardiac tamponade Coronary Circulation Coronary artery disease (CAD), Angina, Coronary vein thrombosis, Coronary artery bypass grafting (CABG) (Arteries and Veins) Fibrous Skeleton of the Valve regurgitation, Valve stenosis, Heart block (due to electrical disruption) Heart Autonomic Nervous System Tachycardia, Bradycardia, Vasovagal syncope, Autonomic dysfunction (ANS) Influence on Heart Foetal Circulation Patent ductus arteriosus (PDA), Patent foramen ovale (PFO), Congenital heart defects Reminder: You must sign the Code of Conduct by Monday, 30th September 2024.  Theme Date Time Location Topics Lecture Thursday 19.09.24 10- Uni Place_4.205 Welcome introduction to anatomy 11am 10.00am Lecture Monday 23.09.2024 10- CS Roscoe 1.010 The heart 11am Workshop Monday 30.09.2024 9-12pm Anatomy classrooms Blood vessels and circulation DR Wednesday 2.10.2024 1-3pm Groups 1-8 Cardiovascular system session Anatomy classrooms Lecture Monday 7.10.2024 10- TBC Consolidation (Lymphatic 11am system/Quiz) DR Wednesday 9.10.2024 1-3pm Groups 9-16 Cardiovascular system session Anatomy classrooms Lecture Monday 21.10.2024 10- TBC Respiratory (Anatomy of thoracic 11am wall and lung) Workshop Monday 28.10.2024 9-12pm TBC Ventilation & respiratory tract DR Wednesday 1-3pm Anatomy classrooms Respiratory system session 30.10.2024 Lecture Monday 4.11.2024 10- TBC Consolidation (Mediastinum/Quiz) 11am DR Wednesday 6.11.2024 1-3pm Anatomy classrooms Respiratory system session  Any questions? ? 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