L1 Anatomy Pericardium & External features of the heart (CVS) PDF

Level ….. Semester 3 Module (CVS)  Pericardium & External features of the heart INSTRUCTOR INFORMATION Name: Prof. Mona Hassan Mohammed Department: Anatomy Office hours: Day Sunday  ‫‪Mission and Vision of Faculty‬‬...

Level ….. Semester 3 Module (CVS)  Pericardium & External features of the heart INSTRUCTOR INFORMATION Name: Prof. Mona Hassan Mohammed Department: Anatomy Office hours: Day Sunday  ‫‪Mission and Vision of Faculty‬‬ ‫رسالت الكلٍت‪:‬‬ ‫تلتزم كلٍت الطب البشري – جاهعت الذلتا للعلوم والتكنولوجٍا بتقذٌن برناهج تعلٍوً تكاهلً هتوٍز ٌقوم‬ ‫على الوھـارة والوعرفـت وٌھـذف الى تخرٌج أطبـاء قـادرٌن على الوفـاء بواجبـاتھن الوھنٍـت واألخالقٍـت‪،‬‬ ‫والتعلٍن الطبً الوستور والوشاركت الفعالت فً البحث العلوً وخذهت الوجتوع‪.‬‬ ‫رؤٌت الكلٍت‪:‬‬ ‫تسعى كلٌة الطب البشري ‪ -‬جامعة الدلتا للعلوم والتكنولوجٌا من خالل تطبٌق برنامج التعلم القائم على‬ ‫اكتســاب الجدارات أن تكون فً مقدمة المؤسسات الطبٌة التعلٌمٌة المتمٌزة على المستوى المحلً‬ ‫والقومى والعالمً‪.‬‬  Learning Outcomes By the end of the lecture, the students will be able to: - Describe pericardium, site, structures and layers - Describe pericardial sinuses and its clinical applied - Describe detailed anatomy of external features of the heart  The Pericardium Definition: Is a fibro-serous sac that encloses the heart and the roots of the great vessels Site: It occupies the middle mediastinum. Composition: Is composed of :- A. Fibrous pericardium and B. Serous pericardium.  1- The fibrous pericardium Is a tough connective tissue, the outer layer lines the boundaries of the middle mediastinum. Shape: It is a cone-shaped bag with its base directed downward on the diaphragm and apex which directed upward toward the neck Pericardiacophrenic Ligament  Relations: 1- The base: It blends with the central tendon of the diaphragm forming → pericardiacophrenic ligament and to a small muscular area of the diaphragm on the left side. 2- The apex: continuous with the adventitia of the great vessels that may reach the pretracheal layer of deep cervical fascia 3- Anteriorly, it is attached to the posterior surface of the sternum by sterno-pericardial ligaments. The phrenic nerves and the pericardiacophrenic vessels passes through it and supply it. These attachments help in retain the heart in its position in the thoracic cavity & limits cardiac distention.  2-The Serous Pericardium It is composed mainly of mesothelium and has 2 layers and a cavity in between: 1- The parietal layer: lines the internal surface of the fibrous pericardium 2- The visceral layer: makes up the epicardium, the outermost of three layers of the heart wall (epicardium, myocardium and endocardium) 3- The pericardial cavity is the space between the parietal and visceral layers of serous pericardium and contains a thin film of fluid  Pericardial Reflections The parietal layer of serous pericardium is continuous with the visceral layers of serous pericardium around the roots of the great vessels. The serous pericardium then reflected in two locations: One superiorly, surrounding the aorta, and pulmonary trunk. The second is posteriorly, surrounding the superior and inferior vena cava, and the pulmonary veins.  A passage between the two sites of reflected serous pericardium called the transverse pericardial sinus. This sinus lies posteriorly to the ascending aorta and the pulmonary trunk, anteriorly to the superior vena cava, and superiorly to the left atrium. The zone of reflection surrounding the veins is J-shaped, and the cul-de-sac formed within the J, posterior to the left atrium called the oblique pericardial sinus.  When the pericardium is opened anteriorly during surgery, a finger placed in the transverse sinus separates arteries from veins. A hand placed under the apex of the heart and moved superiorly slips into the oblique sinus.  Blood of the pericardium Arterial supply: By branches from the internal thoracic, pericardiao-phrenic, musculophrenic, inferior phrenic, and from thoracic aorta.  2- Veinous drainage:- veins from the pericardium drain into azygos, internal thoracic (Pericardiacophrenic veins ) and superior phrenic veins.  Nerves supply by: 1-Visceral pericardium: the same as the heart 2- Fibrous pericardium:- Parasympathetic through vagus nerve Sympathetic through sympathetic trunk. Somatic sensation (pain) through phrenic nerves.  Lymphatic drainage 1. The lymphatics draining the lateral parts of pericardium pass to the anterior mediastinal, tracheobronchial, lateropericardial, prepericardial and posterior mediastinal (juxtaesophageal) lymph nodes. 2. The posterior part of the pericardium drains to the juxtaesophageal and tracheobronchial nodes.  The heart Description A hollow muscular organ. Site: within the pericardium in the middle mediastinum Posterior to the body of sternum and the 2nd to 5th costal cartilages. Anterior to the 5th to 8th thoracic vertebrae A third of it lies to the right of median plane and 2/3 to the left Approximately the size of your fist Wt. = 250-300 grams. It consists of four chambers (right and left atria, right and left ventricles)  External features: The heart is pyramidal in shape having: Apex Base. Two surfaces:  Sterno-costal (anterior surface)  Diaphragmatic (inferior surface) Four borders: Right, left, upper and inferior border  1- Cardiac Apex: Is formed by left ventricle Direction: downwards, forwards and to the left. Sit: deep to the left 5th intercostal space, 1-2 cm medial to the left midclavicular line (9 cm from the midline) The apex beat (point of maximum impulse (PMI)), is the furthermost point outwards (laterally) and downwards (inferiorly) from the sternum at which the cardiac impulse can be felt. Otherwise called cardiomegaly.  2- Cardiac base (posterior surface) oIt is formed by the 2 atria, mainly left atrium and the proximal parts of the great veins (superior and inferior venae cavae and the pulmonary veins). oIt is quadrilateral and directed posteriorly. oLies opposite middle thoracic vertebrae (5-7) and is separated from it by descending aorta, esophagus and oblique sinus of pericardium. oBounded inferiorly by post. part of coronary sulcus , which lodges the coronary sinus and separate it from left ventricle.  Surfaces of the heart: 1-Sternocostal Surface: Is formed mainly by the right atrium and right ventricle, and a lesser portion of left ventricle. It is directed forwards and upwards Divided by anterior part of coronary sulcus (atrio- ventricular groove) which lodge right coronary artery into: Atrial part, formed mainly by right atrium. Ventricular part , the right 2/3 is formed by right ventricle, while the left 1/3 is formed by left ventricle. The 2 ventricles are separated by anterior interventricular groove, which lodges Anterior interventricular artery (branch of left coronary) and Great cardiac vein.  2- Diaphragmatic surface (inferior): The heart in the anatomic position rests on the diaphragmatic surface. Formed by the 2-ventricles, mainly left ventricle (left 2/3). Slightly concave as rests upon the central tendon of the diaphragm. Directed inferiorly & backward. Separated from base of heart by posterior part of coronary sulcus which lodge coronary sinus. The 2-ventricles are separated by posterior interventricular groove which lodges: Posterior interventricular artery and Middle cardiac vein  Borders of the Heart Right border (or right pulmonary surface): formed by right atrium and faces right lung Left border or (left pulmonary surface): faces the left lung, and consists of the left ventricle and left auricle Lower or inferior border: defined as the sharp edge between the anterior and diaphragmatic surfaces of the heart &formed mainly by right ventricle + apical part of left ventricle Upper border: formed by the 2 atria but is masked anteriorly by large vessels of the heart The obtuse margin separates the anterior and left pulmonary surfaces  Four grooves of the heart Coronary sulcus (circular sulcus) which marks the division between atria and ventricles, contains the trunks of the coronary vessels and completely encircles the heart from anterior backward. Interatrial groove: separates the two atria and is hidden by pulmonary trunk and aorta in front. 2 Interventricular grooves: anterior and posterior, mark the division between ventricles (which separates the RV from the LV).  Surface anatomy of the Heart Superior right point at the upper border of the 3rd right costal cartilage one inch from midline. Superior left point at the lower border of the 2nd left costal 1 cartilage 3cm to the left of midline. Inferior left point at the 5th intercostal space, 9 cm from the 2 midline Inferior right point at superior border of the 6th right costal 3 cartilage, 3 cm from the midline 4 Borders of the Heart Upper border: line connecting inferior 2nd L costal 5 cartilage to the superior 3rd R costal cartilage Lower border: line from the inferior R border of the 6 sternum to the intersection of the 5th intercostal space and the midclavicular line Right border : line drawn from 3rd R costal cartilage to 6th R costal cartilage Left border: line from the L ends of the superior and inferior lines  Auscultatory Zones Aortic: RUSB (right upper sternal border) Pulmonic: LUSB (left upper sternal border) Tricuspid: 4LICS (4th left intercostal space), on the sternal border Mitral: 5 LICS (5th left intercostal space), several cm lateral to the 4LICS Apex Beat Located anywhere from the 4th to 5th intercostal space, 9 cm lateral to midline  Layers of the heart wall From outer to inner:- Epicardium : visceral pericardium Myocardium – cardiac muscle layer forming the bulk of the heart Endocardium – endothelial layer of the inner myocardial surface