Please provide a paragrpah explanation answering the following: 5. Valvular sten

Question

Please provide a paragrpah explanation answering the following:

5. Valvular stenosis and valvular regurgitation are diseases of the heart valves that can affect blood flow and cardiovascular function.

a. Explain how heart valves normally work to ensure single-direction blood flow and why that is important to normal cardiovascular function. Include an explanation of the forces involved in causing the valves to open and close.

b. Describe how either of these conditions in the mitral valve would affect blood flow and cardiac output.

c. These conditions may lead to secondary pulmonary hypertension (high blood pressure in the pulmonary circuit) and pulmonary edema (fluid build up in and around the lungs). Explain why these secondary diseases would occur and why they would occur in the pulmonary, rather than the systemic, circuit. Incorporate factors that affect blood flow and pressure, as well as capillary exchange, in your answer.

Explanation / Answer

5.a) The heart valves are designed to open when the blood flow increases towards the valve. Blood flows from top chambers into the bottom chambers due to pumping of blood. The blood pushes the valve open and then after pasing into the bottom chamber the valve closes because it is only designed to open in one direction. That is how the blood flows in one direction only and the valve mechanism prevents it from flowing backwards.

It is important for blood to flow in one direction due to the function of the heart. The heart receives deoxygenated blood from the veins and sends oxygenated blood to the tissues of the body through arteries. If blood flow is not maintained in uni direction the circulation system will collapse and cause metabolic problems both at the level of receiving blood and sending it out.

b) The body tissues require energy to keep up with work. This process requires aerobic respiration. The aorta is the widest artery in the heart through which the mitral valve sends oxygenated blood to the body tissues. During valvular stenosis, the aortic valve gets constricted. Hence during heavy work, the blood flow to the tissues is not enough as would be with a normal aorta. So the person involved can experience a sudden collapse of energy due to decreased cardiac output, that is, the amount of blood pumped out. The amount of blood which gets accumulated due to the lack of flow through the aorta can also cause the blood to build up in the chamber and flow backward.

In valvular regurgitation, the mitral valve does not shut back into position after the flow of blood between the chambers. This can be caused to due anatomical anomalies. The condition can cause backward flow of blood and decreased cardiac output.

c) The left chamber of the heart receive oxygenated blood from the lungs through the pulmonary veins. The blood then passes through the mitral valve into the lower chamber where it connects to aorta. But when the mitral valve does not function properly due to valvular stenosis or regurgitation, causing blood to flow backwards, the blood coming through the pulmonary veins don't get pumped as per heart beat. Hence there is more blood build up and this starts to flow back into the lungs from where it came and flood the region around the lungs. When the capillaries lining the alveolar space recieves the extra blood, due to the pressure build up it diffuses into the lungs and also the interstitial tissues due to the hydrostatic pressure difference created by the extra blood flow.

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