The mitral valve, also called the left bicuspid atrioventricular valve, is located in the left side of the heart between the left atrium and the left ventricle. In relation to the sternum, the mitral valve is positioned posteriorly and is at the height of the 4th costal cartilage of the rib cage (Moore, Dalley and Agur, 2014). The valve is composed of two cusps, the anterior and the posterior cusps, which are held in place by chordae tendinous cords (Snell, R.S. 2004). These cords are tightly held between the papillary muscles and the valve itself (Agur, A M.R. and Dalley, A.F, 2009). The cusps are made of a fibrous piece of tissue which is very strong, the flap of fibrous tissue is covered with a layer of endocardium …show more content…
Valves are found in veins all around the human body as well as in the heart, their role is to prevent the back flow of blood. The movement of the heart when pumping blood around the body is referred to as the cardiac cycle.
To start the cardiac cycle, the sino atrial node sends out electrical impulses, in the form of the movement of potassium (K⁺), sodium (Na+) and calcium (Ca2+) ions (McMaster Pathophysiology Review, 2005). The impulse first travels through the bundle of His, located in the middle of the heart between the two sets of artia and ventricles. The bundle of His then divides into two main branches of fibres, one suppling the impulses to the left side of the heart and the other suppling the impulses to the right side of the heart (Rhind, J, Greig, J, 2002). After traveling down to the length of the fibres, the impulses reaches the apex of the heart, the ventricles start to contract, known as ventricular systole. First the ventricles contract and then as the impulses travel back up the heart through the Purkinje fibres which then causes the contraction of the atria, known as atrial …show more content…
In the heart, there are atrioventricular valves (located between the atrium and the ventricle on both sides of the heart) to prevent the blood from flowing back into the part of the heart, be it a vessel or chamber, that the blood had just travelled on. If there is a backflow of blood then the blood is not being send to the vessels around the body and is instead ‘clogging up’ the system of blood vessels. If the backflow of blood occurs in the heart then the whole of the body is effected rather than just a specific part of the