Bond University Anatomy: Heart & Great Vessels PDF

ANATOMY: HEART & GREAT VESSELS MEDI11-102 (YEAR 1, SEM 2) WEEK 3 Dr. Rossana Nogueira Assistant Professor in Anatomy  Acknowledgement of Country This material has been reproduced and communicated to you by or on behalf of Bond University in...

ANATOMY: HEART & GREAT VESSELS MEDI11-102 (YEAR 1, SEM 2) WEEK 3 Dr. Rossana Nogueira Assistant Professor in Anatomy  Acknowledgement of Country This material has been reproduced and communicated to you by or on behalf of Bond University in accordance with section 113P of the Copyright Act 1968 (Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. 19/09/2024 SESSION LEARNING OBJECTIVES At the end of this session, students should be able to: Identify the vascular structures within the superior mediastinum, specifically the vessels entering and leaving the heart and their functional significance. Describe and explain the position of the heart within the mediastinum. Describe the chambers of the heart and be aware of their individual structures and function. Summarize the flow of blood through the heart. Describe the structure and functions of the heart valves in-situ and via auscultation. Describe the structure and function of the coronary circulation, including (a) the basic arrangement of the main coronary arteries and areas supplied by each; and (b) the venous drainage of the heart. WEEKLY LEARNING OUTCOMES 1. Describe the major structures and functions of the cardiocardiovascular system with an emphasis on the heart. 2. List the central vessels of the coronary circulation.  THE HEART – anterior and posterior views Anterior Posterior  MEDIASTINUM 1. SUPERIOR MEDIASTINUM: (FYI) superior thoracic aperture Transverse thoracic plane (line from the sternal angle to IV disk between T4 and T5 posteriorly) The ‘space’ located between the lungs, bounded anteriorly by 1 the sternum and posteriorly by the vertebral column It is divided into 2 superior (1) and inferior (2) Inferior is then further divided into anterior, middle and posterior ANTERIOR MIDDLE POSTERIOR 2. INFERIOR MEDIASTINUM: Prevascular compartment: Visceral compartment: Posterior to pericardial sac and Potential space with Contains the heart, anterior to mid/low thoracic vertebrae. Extends from transverse thoracic plane to thymus, lymph nodes, fat pericardium and origins Contains esophagus, descending diaphragm and nerves of great vessels aorta, azygous system, thoracic duct  PERICARDIUM A fluid-filled membranous sac that encloses the heart and roots of the great vessels. It protects the heart & provides lubrication to reduce friction between heart and surroundings. LAYERS: Fibrous pericardium = fibro-serous sac continuous with the central tendon of diaphragm. Encloses heart & roots of great vessels Serous pericardium = parietal & visceral layer Pericardial cavity = space between parietal & visceral layers of serous pericardium. Contains thin film of fluid Fibrous ACUTE PERICARDITIS = inflammation of layers of the Pericardium (Anterior wall pericardium. Sharp pain localised to middle or left of Pericardial thorax; radiates to neck or shoulders Sac) CARDIAC TAMPONADE  LAYERS OF THE HEART WALL COMPOSITION: Epicardium (visceral layer of serous), Myocardium (middle) and Endocardium  ATRIA AND VENTRICLES Receivingchambers Pumpingchambers FOUR CHAMBERS: 1. Right atrium 2. Left atrium 3. Right ventricle 4. Left ventricle FOUR SURFACES: 1. Sternocostal surface (formed by right atrium & right ventricle) 2. Diaphragmatic surface (formed mainly by right and left ventricles and inferior surface of right atrium) 3 & 4. Left and Right Pulmonary Surfaces HEART BORDERS * R. heart border (right atrium) * L. heart border (left auricle & left ventricle) * Lower heart border (mainly right ventricle but also R. atrium & L. ventricle) LATERAL VIEWS OF THORACIC CAVITY  THE GREAT VESSELS 1. Superior Vena Cava 2. Inferior Vena Cava 3. Pulmonary veins 4. Pulmonary Trunk (main pulmonary artery) 5. Aorta – 3 parts (ascending, arch, descending/thoracic) 2. Left Common Carotid a. supply: left head & neck 1 5 1. Brachiocepahlic trunk 3. Left Subclavian a. supply: left upper limb 4 Supplies right head, neck, upper limb Ascending Aorta Arch of the Aorta 3 Descending Aorta supplies thorax, abdomen, 3 pelvis and lower extremities A.D.A.M Interactive Anatomy 1997 2 15 Anterior Image credit: Complete Anatomy  THE GREAT VESSELS 1 1. Superior Vena Cava 2. Inferior Vena Cava 5 3. Pulmonary veins 4. Pulmonary Trunk (main pulmonary artery) 5. Aorta – 3 parts (ascending, arch, descending/thoracic) 3 3 A.D.A.M Interactive Anatomy 1997 2 Posterior  REFERENCE IMAGES Anterior Posterior Drake at al. (2020) Gray’s Anatomy for students. CARDIAC PUMPS CARDIAC CYCLE 2 pumps operating in parallel & pumping at the same rate – low- & high-pressure pump. (Pulmonary / Systemic) Atria - receive blood from great vessels Ventricles - pump blood out of heart Image credit: Anatomy & Physiology (Marieb) 3rd Edition CARDIAC PUMPS Blood flows through the heart to reoxygenate blood from the body Gray’s Anatomy CD-ROM  Valves ensure unidirectional blood flow through the heart. They open and close in HEART VALVES: response to pressure changes. The flow of blood through the heart is controlled by four valves: Atrioventricular valves (between atrium and ventricle): o Tricuspid (Right Atrium → Ventricle) (3 cusps) o Mitral (Left Atrium → Ventricle) (2 cusps) The semilunar valves are closed because the (ventriclesrelax) (ventricles contract) ventricular pressure is lower than the aorta and the pulmonary artery After a ventricular contraction, pressure in the ventricles exceeds the pressure Semilunar – between ventricles and great vessels: in the atria, so the AV valves shut. o Pulmonary (R.Ventricle → Pulmonary trunk) o Aortic (L.Ventricle → Ascending Aorta) Image credit: Drake et al.(2020) Gray’s Anatomy for Students ATRIOVENTRICULAR & SEMILUNAR VALVES Image credit: Thieme Atlas of Anatomy 2008 ATRIOVENTRICULAR & SEMILUNAR VALVES ANTERIOR Superior view of aortic valve NOTE THE OPENINGS FOR CORONARY ARTERIES - POSTERIOR perfusion during the diastolic ventricular filling phase INTERNAL STRUCTURE: RIGHT ATRIUM STRUCTURES: ◼ fossa ovalis auricle = increases ◼ crista terminalis surface area ◼ Pectinate muscles ◼ Sino-atrial node (not seen) ◼ Atrio-ventricular node (not seen) Prosected image with gross detail INTERNAL STRUCTURE: RIGHT VENTRICLE STRUCTURES: ◼ chordae tendineae ◼ papillary muscle ◼ trabeculae carneae ◼ Moderator band (h) tricuspid valve; (g) trabeculae carneae  INTERNAL STRUCTURE: LEFT VENTRICLE STRUCTURES: ◼ chordae tendineae ◼ papillary muscle ◼ trabeculae carneae MYOCARDIUM Arterial pressure is MUCH HIGHER in the systemic than pulmonary circulation = the LV performs more work than the right = has a thicker MYOCARDIUM REFERENCE SLIDE Intercostal spaces (spacesbetweentheribs)  HEART AUSCULATION (SOUNDS) ANATOMICAL POSITION OF VALVES AUSCULTATION SITES OF HEART VALVES (aka BEST HEARD) AORTIC VALVE R. of sternum at 2nd intercostal space MNEUMONIC PULMONARY VALVE L. of sternum at 2nd intercostal space ALL PEOPLE TAKE MEDICINE TRICUSPID VALVE L. of sternum at 4th intercostal space Aortic, Pulmonary, Tricuspid, Mitral and Erb's MITRAL VALVE L. of sternum at 5th intercostal space (midclavicular line) ERB’S POINT L. of sternum at 3rd intercostal space  CORONARY CIRCULATION Cardiac muscle needs oxygen-rich blood. The ascending aorta has TWO main collateral branches = LEFT & RIGHT coronary arteries, which supply the myocardium. Right coronary artery (RCA) Origin: right aortic sinus, passes to right side of pulmonary trunk. Gives rise to: Sinoatrial nodal branch (60%) Acute Marginal branch Posterior Interventricular branch RCA supplies: diaphragmatic surface of the heart, the right atrium, most of right ventricle, diaphragmatic part of left ventricle, and posterior third of interventricular septum. Left coronary artery (LCA) Origin: left aortic sinus, passes between the left auricle and left side of pulmonary trunk: Anterior interventricular branch Circumflex artery LCA supplies: left atrium, most of left ventricle, part of right ventricle, anterior two-thirds of IVS, including the AV bundle. REFERENCE SLIDE Image credit: Drake et al.(2020) Gray’s Anatomy for Students CORONARY VEINS Image credit: Drake et al.(2020) Gray’s Anatomy for Students  PERICARDIAL SINUSES 1. TRANSVERSE PERICARDIAL SINUS Located posterior to the roots of the ascending aorta and pulmonary trunk Clinical significance: can be used to identify the arteries of the heart during coronary artery bypass grafting 2. OBLIQUE PERICARDIAL SINUS Located posterior to the left atrium; between R and L pulmonary veins. No clinical significance.  - Heart position & location - Vascular structures (great vessels) - The four chambers of the heart - Internal and external features of the heart - Normal blood flow through the heart, including the four valves - Stethoscope positioning for auscultation - Coronary circulation and its relevance - Pericardial sinuses and its relevance 19/09/2024 bond.edu.au REFERENCES UTILIZED: Clinically Orientated Anatomy by K.L. Moore and A.F. Dalley Essential Clinical Anatomy by Moore and Agur Gray’s Atlas of Anatomy by R.L. Drake and A.W. Vogl