Sinoatrial node

3. Explain the heart generates and conducts an electrical current. Page 388 The heart has its own built-in conduction system for generating action potentials spontaneously and coordinating contractions during the cardiac cycle. All the cardiac muscle fibers in each region of the heart are electrically linked together. The intercalated disks are connections that electrically join the muscle fibers of the heart into a single unit that can conduct electrical impulses through the entire wall of…

conduction system of the heart include the SA node, AV node, Bundle of His and the Purkinje fibers. The sinoatrial node (also known as SA node) is a natural pacemaker and is responsible for depolarization of the right and left atrium. This produces a P wave on the EKG reading which is normally 0.1 second and its normal amplitude is 0.10-.012 mV. The AV node then causes a brief delayed of 0.1 second which allows the ventricles to relax and fill with blood. The AV node then transmits electrical…

The Cardiovascular System is composed of the heart and the blood vessels. The main function of the cardiovascular system is to pump blood around the body. The cardiovascular System is divided into two parts, the systematic circuit and the pulmonary circuit. The systematic circuit contains oxygenated blood and the pulmonary blood contains deoxygenated blood. In order to prevent oxygenated and deoxygenated blood from mixing there is a structure called an interventricular septum. The septum…

2013, pg. 458). The main components: • SA Node • Internodal…

The heart is the organ that pumps blood through the body. Together with the circulatory system it makes up the cardiovascular system (Anatomy of the Heart, 2015). The heart is oddly shaped, almost oval at the bottom but with a series of veins and arteries at the top and sides. It definitely is not “heart” shaped. It is made up of four chambers consisting of two atria (upper) and two ventricles (lower). These chambers are separated into right and left side by the septum, which is a wall of muscle…

Explain the significance of the thickness of the left ventricular wall. The left ventricle works harder as it pumps blood to the systemic circuit, not just to the pulmonary portions as the right ventricular does. Therefore, the left ventricular walls are thicker, to support the hard work that it has to do throughout the body (Martini & Nath,2014 p.685) The major coronary vessels are on the surface of the heart. What is the advantage of that location? The heart has its own blood supply from the…

conduction system of the heart works this way: Step 1: Pacemaker Impulse Generation. The SA node is known a natural pacemaker because it sets the pace of the heartbeat. It is where cardiac muscle contraction begin, from an impulse which causes the right and left atria to contract and push blood into the ventricles. Step 2: AV Node Impulse Conduction. From the atria, the electrical signal spreads to the AV node, a group of cells found between the atria. Step 3: AV Bundle Impulse Conduction. The…

Sometimes when we ingest certain substances, we can stimulate foci (nodes that pace the heart at a certain speed) in the heart which can give us the feeling of “skipping a beat.” The feeling of “skipping a beat” is actually another beat that follows the original beat quickly which gives us that feeling. A lot of factors can stimulate other foci such as atrial and junctional in our heart. These factors, according to Dr. Dubin, includes adrenaline (epinephrine) released by adrenal glands,…

are now in the right side of the heart, literally, the right atrium. The SA node’s action potential fires again and through the tricuspid valve we go. We’re now in the right ventricle. This one is roomy like the left so we have to wait with the AV node until the ventricle fills up some more. Finally! The AV bundle fires and we pump through the pulmonary semilunar valve into the pulmonary trunk and out the pulmonary arteries. We are on our way back to the lungs now. It gets a little small again…

The Mechanics of the Heart An electrocardiogram, or EKG/ ECG, is a non-invasive test that measures the electrical activity of the heart and its electrical patterns. An electrical signal is sent through the heart to produce contractions that move the blood. This is what an EKG measures. In total that test may take from five to ten minutes and are ordered by a doctor to examine the heart more close. An EKG is done while the patient is lying down completely still (in order to reduce artifact or…