Engelsk oversetter til norsk download8/17/2023 We have translators and interpreters that are constantly assessed to provide a quality service and high volumes of work for your company. Available online 24/7 and on site from Monday to Friday from 9 am to 6 pm. We provide free quotations in under an hour. The human heart is a four-chambered muscular organ, shaped and sized roughly like a man's closed fist with two-thirds of the mass to the left of midline. The heart is enclosed in a pericardial sac that is lined with the parietal layers of a serous membrane. The visceral layer of the serous membrane forms the epicardium. Three layers of tissue form the heart wall. The internal cavity of the heart is divided into four chambers: The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium. The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thick-walled chambers that forcefully pump blood out of the heart. Differences in thickness of the heart chamber walls are due to variations in the amount of myocardium present, which reflects the amount of force each chamber is required to generate. The right atrium receives deoxygenated blood from systemic veins the left atrium receives oxygenated blood from the pulmonary veins. Pumps need a set of valves to keep the fluid flowing in one direction and the heart is no exception. The heart has two types of valves that keep the blood flowing in the correct direction. The valves between the atria and ventricles are called atrioventricular valves (also called cuspid valves), while those at the bases of the large vessels leaving the ventricles are called semilunar valves. The right atrioventricular valve is the tricuspid valve. The left atrioventricular valve is the bicuspid, or mitral, valve. The valve between the right ventricle and pulmonary trunk is the pulmonary semilunar valve. The valve between the left ventricle and the aorta is the aortic semilunar valve. When the ventricles contract, atrioventricular valves close to prevent blood from flowing back into the atria. When the ventricles relax, semilunar valves close to prevent blood from flowing back into the ventricles. While it is convenient to describe the flow of blood through the right side of the heart and then through the left side, it is important to realize that both atria and ventricles contract at the same time. The heart works as two pumps, one on the right and one on the left, working simultaneously. Blood flows from the right atrium to the right ventricle, and then is pumped to the lungs to receive oxygen. From the lungs, the blood flows to the left atrium, then to the left ventricle. From there it is pumped to the systemic circulation. The myocardium of the heart wall is a working muscle that needs a continuous supply of oxygen and nutrients to function efficiently. For this reason, cardiac muscle has an extensive network of blood vessels to bring oxygen to the contracting cells and to remove waste products. The right and left coronary arteries, branches of the ascending aorta, supply blood to the walls of the myocardium. Most of the cardiac veins drain into the coronary sinus, which opens into the right atrium.There are normal sounds or noises that may occur when using your dryer.Īfter blood passes through the capillaries in the myocardium, it enters a system of cardiac (coronary) veins. There could also be a sound or noise that may not be normal. The following lists both normal and abnormal dryer sounds.Ī squeak when the dryer is started. This start-up squeak should go away after the first few seconds of operation.Ī squeak that develops after the dryer has heated up but is not heard when the dryer is cool.Ī squeaking that is very short and repeats every few seconds (like a chirping sound). If you are hearing sounds or noises that are not normal, please check the following: To minimize the possibility of electric shock, unplug this appliance from the power supply before attempting any maintenance or cleaning. The sound should go away after the first few seconds of operation. If the sound continues, we recommend you contact service. Gas dryers may produce a buzzing when the solenoid valve opens.
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