Conducting system of heart

This article will discuss the components of the heart’s conduction system including their anatomy and clinical significance. The heart has two main types of cells: 1 • Conducting cells: generate and propagate electrical impulses. • Contractile (muscle) cells: contract following receipt of electrical impulses. These cells can also propagate and, on occasion, generate electrical impulses. Both conducting and specialised muscle cells form the hearts conduction system and orchestrate cardiac contraction. The electrical system is intrinsic to the heart meaning that contraction can persist in the absence of neuronal input. Components of the cardiac conduction system The cardiac conduction system involves the spread of electrical activity from the sinoatrial node, to the atrioventricular node, down the bundle of His and along the Purkinje fibres. As the electrical activity spreads along the heart’s conduction system it initiates myocardial contraction in the surrounding myocardial tissue. Cardiac conduction system 3 The sinoatrial node (SAN) • The sinoatrial node (SAN) is of a group of cells found high up in the right atrium close to its junction with the superior vena cava. 1,4,5 • The SAN functions as the heart’s intrinsic pacemaker, regulating heart rate. • The SAN spontaneously generates electrical impulses which are transmitted to the right and left atrium. • These electrical impulses stimulate the atrial myocardium to contract. • Atrial muscle conducts relatively fast (0.5m...

The heart's electrical system In the simplest terms, the heart is a pump made up of muscle tissue. Like all muscle, the heart needs a source of energy and oxygen to function. The heart's pumping action is regulated by an electrical conduction system that coordinates the contraction of the various chambers of the heart. How does the heart beat? An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node). This is a small mass of specialized tissue located in the right upper chamber (atria) of the heart. The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions. The atria are then activated. The electrical stimulus travels down through the conduction pathways and causes the heart's ventricles to contract and pump out blood. The 2 upper chambers of the heart (atria) are stimulated first and contract for a short period of time before the 2 lower chambers of the heart (ventricles). The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node). There, impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles. The bundle of His divides into right and left pathways, called bundle branches, to stimulate the right and left ventricles. Normally at rest, as the electrical impulse moves through the heart, the heart contracts about 60 to 100 times a minute, depending on a person's ag...

The conducting system of heart (electrical conduction) in the heart allows the impulse that is generated by the sinoatrial node (SA node) of the heart to be propagated to (and stimulate) the cardiac muscle (myocardium). Signals arising in the SA node (located in the right atrium) stimulate the atria to contract and travel to the AV node, which is located in the interatrial septum. After a delay, the stimulus diverges and is conducted through the left and right bundle of His to the respective Purkinje fibers for each side of the heart, as well as to the endocardium at the apex of the heart, then finally to the ventricular epicardium. IMAIOS and selected third parties, use cookies or similar technologies, in particular for audience measurement. Cookies allow us to analyze and store information such as the characteristics of your device as well as certain personal data (e.g., IP addresses, navigation, usage or geolocation data, unique identifiers). This data is processed for the following purposes: analysis and improvement of the user experience and/or our content offering, products and services, audience measurement and analysis, interaction with social networks, display of personalized content, performance measurement and content appeal. For more information, see our You can freely give, refuse or withdraw your consent at any time by accessing our cookie settings tool. If you do not consent to the use of these technologies, we will consider that you also object to any cooki...

[ "article:topic", "pacemaker", "T wave", "spontaneous depolarizationv", "sinus rhythm", "sinoatrial (SA) node", "QRS complex", "Purkinje fibers", "prepotential depolarization", "P wave", "myocardial contractile cells", "myocardial conducting cells", "internodal pathways", "intercalated disc", "interatrial band", "heart block", "electrocardiogram (ECG)", "bundle of His", "Bachmann\u2019s bundle", "autorhythmicity", "atrioventricular (AV) node", "atrioventricular bundle branches", "atrioventricular bundle", "artificial pacemaker", "license:ccby", "showtoc:no", "source[1]-med-755", "source[2]-med-755", "program:oeri", "authorname:humananatomyoeri" ] \( \newcommand\) • • • • • • • • • • • • • By the end of this section, you will be able to: • Describe the structure of cardiac muscle tissue and cells • Identify and describe the components of the conducting system that distributes electrical impulses through the heart Recall that cardiac muscle shares a few characteristics with both skeletal muscle and smooth muscle, but it has some unique properties of its own. Not the least of these exceptional properties is its ability to initiate an electrical potential at a fixed rate that spreads rapidly from cell to cell to trigger the contractile mechanism. This property is known as autorhythmicity. Skeletal muscle can not do this. Even though cardiac muscle has autorhythmicity, heart rate is modulated by the endocrine and nervous systems. Structure of Cardiac Muscle Tissue and Cells Co...

Introduction The intrinsic conduction system of the heart is comprised of several specialized subpopulations of cells that either spontaneously generate electrical activity (pacemaker cells), or preferentially conduct this excitation throughout the four chambers of the heart in a coordinated fashion. This tutorial will discuss details of this anatomy, as well as physiologic properties of the system. The cardiac action potential underlies signaling within the heart, and various heart cell (myocyte) populations elicit characteristic waveforms. The active sensing (or recording) of these action potentials is important in both research and clinical studies. Although each myocyte within the heart has the capacity to conduct an electrical cardiac impulse (be excitable), there are specific myocytes that generate cardiac action potentials and/or preferentially conduct them from the atrial to the ventricular chambers. This cellular network has become known as the "conduction system" [1]. The orderly contractions of the atria and ventricles are regulated by the organized transmission of electrical impulses that pass through these modified cardiac muscle cells; these specialize cells are interposed within the contractile myocardium. More specifically, this intrinsic conduction system is thought to be comprised of the following subpopulations of cells: 1) pacemaker cells, those that spontaneously generate electrical activities; and 2) conduction fibers (in the ventricles, Purkinje fibe...

Overview Anatomy of the heart and its electrical system What is the cardiac conduction system? The human heart is an engine that has to work 24/7 to keep you alive, and it has to be reliable and effective. To do this, it relies on a specialized network of cells called the cardiac conduction system. It’s also known as your heart’s electrical system. Cells in the cardiac conduction system can generate electrical impulses and then distribute the signal throughout your heart. While all cells in your heart can conduct electricity, the cells in this system conduct it at very specific speeds. This is how different parts of your heart beat at just the right time. The parts of the cardiac conduction system are (in order, starting where electricity is generated): • The sinoatrial (SA) node. • The atrioventricular (AV) node. • The Bundle of His. • Bundle branches. • Purkinje fibers. Function What does the cardiac conduction system do? Your body uses electrical impulses to control when your muscles flex and relax, and your heart is no different. However, your heart needs to do this 24/7, whether you’re asleep or awake. To do this, it relies on a specific part of your nervous system called the autonomic nervous system. This is the unconscious part of your nervous system, and it runs the functions of your body that you don’t think about. This includes your heart, breathing, digestion and more. The timing of your heart muscle’s action is also critical. Rather than your brain firing the e...