klaffarna

Klaffarna, in medical usage, are flexible flaps that regulate the flow of liquids and prevent backflow within vessels and chambers. In humans, the cardiovascular system contains four heart valves: two atrioventricular valves, the mitral (between the left atrium and left ventricle) and the tricuspid (between the right atrium and right ventricle); and two semilunar valves, the aortic (between the left ventricle and the aorta) and the pulmonary (between the right ventricle and the pulmonary artery). The valves differ in structure: atrioventricular valves have leaflets connected to chordae tendineae and papillary muscles, while semilunar valves consist of three cusps forming pockets when closed.

During the cardiac cycle, pressure changes drive the opening and closing of the valves in a coordinated sequence. When the ventricles contract, the atrioventricular valves close to prevent backward flow into the atria, producing the first heart sound; as the ventricles relax and fill, the semilunar valves close, producing the second heart sound. Healthy valves are flexible and resilient; damage or disease can impair function.

Common valve disorders include stenosis (narrowing) and regurgitation (leakage). Causes include congenital defects, age-related degeneration, rheumatic heart disease, infections such as endocarditis, and myocardial infarction–related damage. Symptoms may include shortness of breath, fatigue, chest pain, or swelling, depending on the valve affected.

Diagnosis relies on physical examination and imaging, especially echocardiography. Treatment ranges from observation and medical therapy to valve repair or replacement, including mechanical or bioprosthetic valves, and, when suitable, transcatheter approaches.

Klaffarna also refer to valves in other parts of the circulatory system, notably venous valves that help prevent backflow in the limbs and abdomen.