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A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart.A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart.
Attempts to improve the design of the valve and speed manufacturing, however, led to a weaker structure, with serious consequences. Beginning in 1979, Björk–Shiley valves with the convexo-concave design had a tendency to develop fractures in the outflow strut which could result in catastrophic valve failure and possibly sudden cardiac death.
An artificial heart valve is a one-way valve implanted into a person's heart to replace a heart valve that is not functioning properly (valvular heart disease).Artificial heart valves can be separated into three broad classes: mechanical heart valves, bioprosthetic tissue valves and engineered tissue valves.
The mitral valve is typically 4 to 6 square centimetres (0.62 to 0.93 sq in) in area and sits in the left heart between the left atrium and the left ventricle. [5] It has two cusps: an anterior one, and a posterior one. [6]
The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle.The function of the valve is to allow blood to flow from the right atrium to the right ventricle during diastole, and to close to prevent backflow (regurgitation) from the right ventricle into the right atrium during right ventricular ...
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta.It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve.
In humans the lungs are located in the chest on either side of the heart in the rib cage.They are conical in shape with a narrow rounded apex at the top, and a broad concave base that rests on the convex surface of the diaphragm. [1]
Lingual papillae (sg.: papilla) are small structures on the upper surface of the tongue that give it its characteristic rough texture. The four types of papillae on the human tongue have different structures and are accordingly classified as circumvallate (or vallate), fungiform, filiform, and foliate.