Human Anatomy and Physiology II
Kristen Ammen
The mitral valve is located on the left side of the heart between the left atrium and left ventricle. The purpose of the mitral valve is to form a seal between these two chambers of the heart to prevent the back flow of blood. When blood enters the left side of the heart, it is oxygenated and enters through the pulmonary veins. The blood then travels through the left atrium; the bicuspid (mitral) valve then opens to let the blood flow down to the left ventricle. The left ventricle contracts, causing the mitral valve to close (preventing the backflow of blood).When the left ventricle contracts it is pumping the blood out to the remainder of the body. (Jenkins, 2007)
The mitral valve is made up of two thin leaf like structures that resembles the look of a parachute. The valve is attached to the wall of the left ventricle by a stringy structure called chordae tendineae. When a patient is affected by mitral valve prolapse, the structure of the valve and the chordae tendineae are affected by myxomatous degeneration. An abnormal thickening of the valve flaps is caused by a build-up of small collagen tumors. (American Heart Association, 2013) The prolapse is caused by the inability for the chordae tendineae to pull the valve tight during the late stages of systole. As the left ventricle decreases in size the chordae fails to maintain tension on the mitral valve, therefore causing regurgitation into the left atrium. (Systolic Murmurs- Mitral Valve Prolapse)
When the valve does not close properly it can cause mitral regurgitation. Mitral regurgitation is the leaking of blood from the left ventricle back into the left atrium. Mitral regurgitation can cause the heart to enlarge and over work to compensate for the blood that has traveled back into the atrium. (National Heart, Lung, and Blood Institute, 2011) This in return can lead to the development of heart failure. Regurgitation can also cause an
References: American Heart Association. (2013, February 18). Retrieved from www.heart.org: http://www.heart.org/HEARTORG/Conditions/More/HeartValveProblemsandDisease/Problem-Mitral-Valve-Prolapse_UCM_450441_Article.jsp Jenkins, K. (2007). Anatomy and Physiology . In From Science to Life. John Wiley and Sons, Inc. National Heart, Lung, and Blood Institute. (2011, July 1). Retrieved from www.nhlbi.nih.gov: http://www.nhlbi.nih.gov/health/health-topics/topics/mvp/ Systolic Murmurs- Mitral Valve Prolapse. (n.d.). Retrieved from http://www.med.ucla.edu: http://www.med.ucla.edu/wilkes/MVPmain.htm