Pericardium 2023 PDF

PERICARDIUM 1 2 Clinical Relevance: Cardiac Tamponade • The relatively inextensible fibrous pericardium can cause problems when there is an accumulation of fluid, known as pericardial effusion, within the pericardial cavity. • This rigidity means that the heart is subject to the resulting incre...

PERICARDIUM 1 2 Clinical Relevance: Cardiac Tamponade • The relatively inextensible fibrous pericardium can cause problems when there is an accumulation of fluid, known as pericardial effusion, within the pericardial cavity. • This rigidity means that the heart is subject to the resulting increased pressure. • The chambers can become compressed, thus compromising cardiac output. • The causes of tamponade are many and varied, and include haemopericardium (blood in the pericardium) and pericarditis. 3 Pericardial effusion 25 cc 4 Chest x-ray- Pericarditis 5 Pericarditis • Pericarditis, or inflammation of the pericardium, has myriad of causes, including bacterial infection and myocardial infarction. • The main symptom is chest pain, but it can also cause acute cardiac tamponade due to an accumulation of fluid in the pericardial cavity. 6 7 8 THE PERICARDIUM In scientific terms, the pericardium is a fibro-serous, fluid filled sack that surrounds the muscular body of the heart and the roots of the great vessels (the aorta, pulmonary artery, pulmonary vein and the superior and inferior vena cava). 9 Pericardium 10 11 Functions • Fixes the heart • Prevents overfilling of the heart • Lubricates • Protects from infection 12 Functions • Fixes the heart in the mediastinum and limits its motion – this is due to its attachment to the diaphragm, the sternum and the tunica adventitia (outer layer) of the great vessels • Prevents overfilling of the heart – The relatively inextensible fibrous layer of the pericardium prevents the heart from increasing in size too rapidly, thus placing a physical limit on the potential size of the organ • Lubrication – A thin film of fluid between the two layers of the serous pericardium reduces the friction generated by the heart as it moves within the thoracic cavity • Protection from infection – The fibrous pericardium serves as a physical barrier between the muscular body of the heart and adjacent organs prone to infection, such as the lungs. 13 Component Parts Inner Serous layer Pericardium Outer Fibrous layer Inner visceral Outer Parietal Single Layer 14 15 16 17 18 19 20 21 Situation of Pericardium 5/8 2/6 22 Anatomical Structure The pericardium is made up of two main layers – a tough external layer known as the fibrous pericardium, and a thin, internal layer known as the serous pericardium. 23 Fibrous Pericardium • Continuous with the central tendon of the diaphragm, the fibrous pericardium is made of tough connective tissue and is relatively non-distensible. • This rigidity prevents rapid overfilling of the heart, but can have several serious clinical consequences (cardiac tamponade). 24 Serous Pericardium • Enclosed within the fibrous pericardium, the serous pericardium is itself divided into two layers – the outer parietal layer which lines the internal surface of the fibrous pericardium and the internal visceral layer which forms the outer layer of the heart (also known as the epicardium). • Each layer is made up of a single sheet of epithelial cells, known as mesothelium. • Found between the outer and inner serous layers, is the pericardial cavity, which contains a small amount of lubricating serous fluid. • This fluid serves to minimize the friction generated by the heart as it contracts and moves about within the thoracic cavity. 25 Vascular supply Arterial Supply• Fibrous and Parietal Pericardium - internal thoracic Artery, Descending thoracic aorta • Visceral Pericardium- coronary arteries Venous Drainage• Fibrous and Parietal Pericardium- Azygous & internal thoracic vein • Visceral Pericardium- drain into coronary sinus 26 Innervation • The phrenic nerve (C3-C5) is responsible for the innervation of the pericardium, as well as providing motor and sensory innervation to the diaphragm. • Fibrous and Parietal Pericardium- Phrenic nerve • Visceral Pericardium – Vagus and sympathetic nerves 27 • Originating in the neck and travelling down through the thoracic cavity, the phrenic nerve is a common source of referred pain, with a key example being shoulder pain experienced as a result of pericarditis. 28 30