A General Overview of Nerve Conduction and Contraction in Cardiac Tissue
The movement of blood through the human body is highly dependent on the heart to conduct electrical impulses and perform contraction in an efficient and effective manner. Failure of the heart to function properly results in rapid destabilization of the body and death. The fact that heart disease has become one of the top contributors to mortality in developed countries makes it one of the most pressing public health concerns in modern history. Much of the current cardiac health crisis has been caused by the widespread adoption of diets high in fat and a lifestyle that includes little to no physical activity. Within the cardiac care industry, many professionals believe that increased public awareness about how the heart functions and the need for heart healthy diets and exercise holds the most promise for reversing the trend towards a higher prevalence of heart disease in the United States.
The human heart consists of four chambers that are designed to move blood through the body in a timely and effective manner. The right side of the heart contains a small chamber that is called an atrium that is tasked with forcing blood into a larger chamber that is called a ventricle. The atrium rests on top of the ventricle and is separated from the ventricle by a valve that prevents the backflow of blood during ventricular contraction. The right ventricle is larger than the atrium because it is responsible for forcing blood into the lungs against greater resistance. The left side of the heart has the same atrium and ventricle design, but the left ventricle is responsible for moving blood into the vessels that carry blood to the rest of the body.
In order for blood to flow in the proper direction through the heart, it is critically important for the atria to contract before the ventricles. This process allows the atria to push blood into the ventricles and forces the atrioventricular valves shut before the ventricles are told to contract. Once the ventricles have been filled, an electrical signal passes along the ventricular nerve pathways and causes all of the cells in the ventricles to contract together. The uniform contraction of all cells within a chamber ensures that the maximum amount of force is applied toward forcing blood out of the heart.
The passage of electrical signals through the heart is initiated at an area of cardiac tissue that is referred to as the sinoatrial (SA) node and is located near the top of the right atrium. A series of nerves branch off from the SA node and pass through the atria before converging at the atrioventricular (AV) node located near the convergence of all four chambers. Once the SA node has initiated an electrical impulse, it travels through the atria toward the AV node causing atrial contraction as it passes. This contraction fills the ventricles with blood and causes the valves between the atria and ventricles to snap shut. At this point, the ventricles are prepared to force blood out into the body as soon as the electrical impulse is conducted through the ventricular nerve pathways.
Near the bottom of the AV node is an area of cardiac tissue that is called the Bundle of His. This tissue is the point from which the right and left ventricular bundle branch nerves originate. The electrical impulse that was created by the SA node travels along these branches as it passes through the left and right ventricles. Small nerve fibers that communicate directly with cardiac cells originate from these branches and provide a pathway for electrical signals to diffuse throughout the ventricular chambers. A series of cellular interconnections allow for the rapid dissemination of electrical signals.
The electrical activity of the heart is monitored by an EKG technician who specializes in the administration of electrocardiograms and the interpretation of the ECG. To learn more about the many opportunities offered by this profession be sure to check out http://www.ekgtechniciansalary.org/ where you will find details about employment standards in different states along with links to professional organizations and national certification agencies.