The Role Of Aortic Valves In The Cardiovascular System

The heart is a vital organ, which pumps blood around the body which allows all of the cells and organs in the body to receive oxygen and nutrients that they require to function. It is a part of the cardiovascular system which also includes the blood vessels and veins. Within the heart, there are four chambers – two atria and two ventricles- and between each chamber there is a valve which blood flows through as it leaves the chamber. Valves have the physiological role of preventing blood flowing backwards through the heart. Unidirectional flow is critical and allows the heart to function in the most efficient way possible (Moore, 2014). The mechanism in which the heart valves work is complex and crucial in the cardiovascular system. If the

The mitral valve and tricuspid valves are known as atrioventricular valves as they are found between the left and right atrium and ventricles in the heart. The mitral valve is located between the left atrium and left ventricle. The pulmonary valve and aortic valve are known as semilunar valves. The role of all four valves is to prevent backwards blood flow, however the mitral valve differs in structure to that of the other three heart valves. The mitral valve is made up of two cusps a large anterior cusp and a smaller posterior cusp, an annulus, chordae tendineae and two papillary muscles (Watton, 2008). The other three valves in the heart, the aortic, pulmonary and tricuspid all have three half-moon shaped cusps (Anonymous, c.2015). Valve cusps can also be known as valve leaflets. Figure 1 illustrates the mitral valve and the positioning of its apparatus (Kanjanuthai,

This can be can be congenital, however the main cause of mitral valve stenosis is rheumatic fever, which is characterized by swelling and inflammation of the joints (Awtry, 2006). Stenosis causes an obstruction which affects left ventricle filling because the mitral valve is narrowed normally due to thickened, calcified or scarred valve cusps. The narrowed valve cusp means less blood can move out of the left atrium into the ventricle during ventricular contraction. This causes an increase in left atrium pressure which leads to decreased cardiac output (decreased volume of blood pumped out by the heart) and an increase in pressure in the pulmonary artery (Chung, Tighe, 1999). Atrial fibrillation (irregular heart beat) also occurs as a result of mitral stenosis and this can also lead to cardiac failure in serious cases of the disease (Julian, 2004). However, there are a variety of medications that can be taken to help maintain the heart suffering stenosis such as beta blockers, diuretics and in some more advanced cases, surgery (Awtry,