The heart is encased in two protective layers. The outer layer, the pericardial sac, covers the heart. It folds in on itself at the aortaBegins with the aortic valve, the largest main vessel that carries oxygenated blood from the ventricles to the body. Major Vessels 1. Six Second ECG Guidebook (2012), T Barill, p. 15, 190 forming the epicardial surface of the heart. Between these layers is a small amount of fluid that provides a non-stick surface between these layers.
PericarditisThe presence of ST elevation in most views of a 12 lead ECG suggests pericarditis. Pericarditis, an inflammation to the pericardial lining of the heart often attributed to infection, also produces ST elevation on a 12 lead ECG. In fact,..., an infection within the pericardial sac, can cause increased friction between the inner surfaces of these layers. Chest discomfort is common. A friction rub, a sound similar to that produced by rubbing leather together – may also result. Note also that an accumulation of relatively small amounts of fluid (200 ml) in this pericardial sac – pericardial effusions – can straight jacket the heart’s ability to contract. This condition called cardiac tamponadeExcess fluid between the parietal and pleural layers surrounding the heart restrict the contraction of the heart; early signs of cardiac tamponade may be a narrowing range between systolic and diastolic blood pressures and elevated jugular venous distension. Pericarditis, an... may result in little or no cardiac outputWhat is it? Why is it Vital? The amount of blood pumped out of the ventricle in a minute (most often refers to the blood pumped by the left ventricle) What is cardiac output? Simply, cardiac output is the amount....
The epicardiumThe external layer that covers the heart – also called the visceral layer of the heart; between the visceral layer and the outer parietal layer is the pericardial sac; note that the coronary arteries travel along the epicardium before burrowing... forms the outer layer of the heart. The myocardiumThe muscle layer of the heart; the middle layer that is responsible for contraction of the heart. The muscular myocardium is the thickest layer and the workhorse of the heart. It is composed of specialized muscle and electrical cells that... forms the middle layer and the endocardiumThe smooth innermost layer of the heart covers the inner chambers and the cardiac valves. The mechanical structures of the heart include the heart’s layers, chambers, septum, valves, and the major vessels (including the coronary arteries). Each of these structures... the innermost layer of the heart.
The coronary arteriesThe coronary arteries provide blood to the heart tissues, carrying blood first across the epicardium, then the myocardium and finally terminating in the endocardium. The epicardium forms the outer layer of the heart. The myocardium forms the middle layer and... provide blood to the heart tissues, carrying blood first across the epicardium, then the myocardium and finally terminating in the endocardium.
The endocardium claims the dubious position as the terminus for the coronary arteries. Since the coronary arteries begin along the epicardial surface, enter the myocardium and terminate in the endocardium, myocardial ischemiaInsufficient supply of oxygen to meet the oxygen demands of tissue. Anaerobic metabolism becomes increasingly important during periods of ischemia. Ischemia results from an inadequate blood flow that fails to meet the oxygen demands (energy demands) of tissues. If tissues... rarely occurs without endocardial ischemia. While the endocardium is damaged in most every myocardial infarctionThe necrosis or death of myocardial tissue due to insufficient supply of oxygen to the infarcted region. The ability to identify cardiac ischemia, injury and infarction is vital in the management of the majority of cardiac emergencies. Most sudden cardiac..., the epicardium’s location in the blood flowThe purpose of the cardiac cycle is to effectively pump blood. The purpose of the cardiac cycle is to effectively pump blood. The right heart delivers deoxygenated blood to the lungs. Here oxygen is picked up and carbon dioxide is... hierarchy increases its safety factor.
The endocardium releases hormones such as:
– endocardinOne of the hormones released by the endocardium is endocardin; a substance that prolongs myocardial contraction. The endocardium releases hormones such as: - endocardin, a substance that prolongs myocardial contraction; - atrial natriuretic factor (ANF), released by the atria to..., a substance that prolongs myocardial contraction;
– atrial natriuretic factorOne of the hormones released by the endocardium is atrial natriuretic factor (ANF); which is released by the atria to oppose the activity of epinephrine, endothelin and the renin-angiotensin system. The endocardium releases hormones such as: - endocardin, a substance... (ANF), released by the atriaRight and left atria (1/3 volume and muscle mass of the ventricles) pump blood to the ventricles. Chambers and Layers of the Heart 1. Six Second ECG Guidebook (2012), T Barill, p. 190 to oppose the activity of epinephrine, endothelin and the renin-angiotensin system
– brain natriuretic peptideOne of the hormones released by the endocardium is brain natriuretic peptide (BNP); which is released by the ventricles upon ventricular distention having similar effects to ANF. The endocardium releases hormones such as: - endocardin, a substance that prolongs myocardial... (BNP) which is released by the ventriclesThe larger chambers of the heart (3 times the volume and muscle thickness than the atria), responsible for the pumping of blood to the lungs and the rest of the body. upon ventricular distention having similar effects to ANF.
The heart is not just a pump but also an endocrine organ!
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 10