Heart Anatomy PDF

Pericardium and External Features of the Heart Learning Outcomes -Describe the layers and function of the pericardium and its Cli...

Pericardium and External Features of the Heart Learning Outcomes -Describe the layers and function of the pericardium and its Clinical correlations -Describe and locate the pericardial cavity and its sinuses. -Describe the anatomical position of the heart and the points of auscultation. -Describe the surfaces and borders of the heart including its vascularization. -Locate the sulci of the heart and mention its contents. Dr. Rana Aly Elbeshbeishy Professor, Anatomy Department, RAKCOMS, RAKMHSU MBBS, MSc, PhD (Anatomy), Faculty of Medicine, ASU, Egypt MHPE Ottawa U, Canada [email protected] Office- 209, First Floor, Ext. 262 Overview of the The Heart Mediastinum Cone-shaped; hollow muscular organ. Thorax comprised of two lateral pulmonary cavities and one central space (Mediastinum). Pumps blood to various parts of the body. Position and surface marking Sup. Boundary: Superior Thoracic Aperture (1st rib/costal cartilage, manubrium, T1 body) Lies in the Mediastinum (space between the lungs). Formed of 4 chambers: 2 atria & 2 ventricles, Sternal Transverse T4/T5 Angle thoracic plane5 IV Disc separated by atrioventricular (coronary) groove. 6 Interatrial septum: between right & left atria. 7 Interventricular septum: between right & left 8 ventricles. Inferior Note: Relative position of heart has degree Surrounded by the pericardium. Boundary: of variability (size of heart, mobility of Diaphragm diaphragm, gravity)  The Heart in situ Pericardium 2 contains fluid (lubricant) Serous Fibrous 6 pericardium pericardium Note: -Heart located in middle mediastinum, posterior to sternum; valves in viscinity of intercostal spaces -Phrenic nerves (C3-C5; traveling with pericardiacophrenic arteries/veins) travel in lateral margin of pericardium on the way to the diaphragm; supplies pericardium Parietal Visceral -Fibrous pericardium (tough, outer layer of pericardium in which the heart is located) is anchored to diaphragm layer layer Fibrous pericardium Serous pericardium Inner layer; closed serous sac inside fibrous pericardium - Outer layer; - Thick strong fibrous sheath - forms a sac to prevent Parietal Visceral overdistension of heart. layer layer - Its base is adherent to central outer layer of serous (epicardium): inner layer, tendon of diaphragm below pericardium; lines of serous pericardium; - attached to back of sternum by Superior & fibrous pericardium adherent to heart. Inferior sterno-pericardial ligaments Sterno- - Nerve supply: phrenic nerve pericardial Nerve supply: phrenic nerve ligaments Nerve supply: autonomic nerves - What is its Blood supply? - What are its contents? Between the 2 layers: is the pericardial cavity; contains fluid (lubricant). - Mention its relations for Lubrication to facilitate heart contraction  1 The Pericardium: 3 layers 1) Fibrous pericardium (Tough) 2) Parietal layer of serous pericardium: lines internal aspect of fibrous pericardium 3 3) Visceral layer of serous pericardium: coating heart itself 2 Pericardial cavity: Thin potential space between layers 2 and 3; normally contains thin lubricating layer of serous fluid 2 1 3 Bare area of Pericardium In general: pericardial layers serve to anchor, protect, support the heart Pericardial Sinuses (2) Clinical Anatomy Cardiac Tamponade: Effusion in pericardial cavity i.e. filling of pericardial sac with excessive amount of fluid (serous or blood) → can compress atria & prevents their filling; due to unyielding fibrous pericardium → results in tachycardia Pericardiocentesis: The drainage of pericardial effusion (typical sites: 5th or 6th left Transverse Sinus: behind the great vessels (Ascending Aorta, Pulmonary Trunk) and in front of the intercostal space near sternum or through infrasternal angle); note that SVC & 2 atria; surgically relevant (clamping/ligating point of access) emergency situations may require thoracotomy and incision of pericardial sac Oblique sinus: behind base of heart formed by left atrium (posterior aspect of heart); bordered by entry Pericarditis: inflammation of the serous pericardium. points of the four pulmonary arteries into left atrium  External Features of Heart 2 Pericardial Sinuses Transverse Sinus Oblique sinus External Features of Heart: Apex/Base Heart Orientation: Surfaces (4) Inferior View, Transverse Plane Anterior View Posterior View Four surfaces: Left pulmonary: LV mainly + L auricle LA RA Right pulmonary: RA Anterior (Sternocostal): RV mainly + Apex of Heart: Formed by Left Ventricle only; directed downward, RA + LV forward & to the left -surface anatomy: 5th Left intercostal space; 3.5 inches (9 cm) from the Diaphragmatic (inferior) (obscured in midline; near the midclavicular line, approximately where mitral valve can this image since heart is sitting on be heard this surface): Mostly LV + RV Base of Heart (posterior surface): Formed mainly of Left Atrium (LA) + a small part of right atrium (RA); Directed upward, backward and to the right.; Separated from inferior surface by coronary (atrio-ventricular) sulcus (groove).  Sterno-costal Surface Diaphragmatic Surface – Anterior surface. – Formed of: Inferior surface right atrium (RA). Formed mainly of left ventricle (2/3) and partly by right ventricle (1/3). right ventricle (RV) & left RA ventricle (LV). Separated from the base of heart by coronary sulcus (atrio-ventricular LV RV Shows atrio-ventricular LV groove). groove (coronary) and RV Shows posterior interventricular anterior interventricular sulcus. groove. Heart Orientation: Borders (4) External Anatomy: Sulci/Grooves (4) Anterior Posterior View View Four borders (three are easily imaged clinically): Anterior interventricular groove (sulcus): between RT & LT ventricles on anterior (sternocostal) surface; anterior interventricular artery and great cardiac vein run in this groove Left: LV + Left auricle Posterior interventricular sulcus (groove): between RT & LT ventricles on diaphragmatic surface, Right: RA posterior interventricular artery and middle cardiac vein run in this groove Atrioventricular (Coronary) sulcus: between atria &ventricles; right coronary artery (RCA) runs in this Superior: RA + LA (poorly defined during imaging; groove anteriorly. Coronary sinus, circumflex artery & continuation of RCA run in this groove posteriorly hidden by the aorta and pulmonary trunk ) Sulcus terminalis: groove between right auricle (rough pectinate muscle internally) and right atrium Inferior: Mostly RV + apex of LV proper (smooth internally); corresponds internally with crista terminalis that divides smooth and rough  External Anatomy: Great Vessels Entering/Exiting Heart SVC Aorta (Arch) leaving left ventricle Pulmonary Trunk (divides into R+L Pulmonary arteries) Leaving right ventricle Pulmonary SVC Veins IVC entering left atrium IVC Note: Ligamentum Arteriosum is the fibrotic remnant of ductus arteriosus The atria have associated auricles (anterior, ear-like extensions) that are derived from primordial atria (auricles are rough internally, lined with pectinate muscle) Surface Anatomy of the Heart Test Yourself Test Yourself