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Anatomy photo:20:26-0105 at the SUNY Downstate Medical Center — "Heart: The Left Atrioventricular (Mitral) Valve" (anterior, posterior papillary muscles) Atlas image: ht_rt_vent at the University of Michigan Health System} — "Right atrioventricular bundle branch, anterior view" Definition of Papillary muscle; MedicineNet Search Results
Parachute mitral valve occurs when all the chordae tendineae of the mitral valve attach to a single papillary muscle. [9] [10] [11] This causes mitral valve stenosis at an early age. [10] It is a rare congenital heart defect. [11] Although it often causes mitral insufficiency, it may not present any symptoms. [10]
The trabeculae carneae and the papillary muscles make up a significant percentage of the ventricular mass in the heart (12-17% in normal human adult hearts), and are correlated with ventricular end diastolic volume. [5] Trabeculae ratios of capillary-to myocyte differ between the walls of the right and left ventricle.
The moderator band (also known as septomarginal trabecula [1]) is a band of cardiac muscle found in the right ventricle of the heart. [2] [3] [4] It is well-marked in sheep and some other animals, including humans. It extends from the base of the anterior papillary muscle of the tricuspid valve to the ventricular septum. [2]
The papillary muscles attach the mitral valve (the valve between the left atrium and the left ventricle) and the tricuspid valve (the valve between the right atrium and the right ventricle) to the wall of the heart. If the papillary muscles are not functioning properly, the mitral valve may leak during contraction of the left ventricle.
The papillary muscles extend from the walls of the heart to valves by cartilaginous connections called chordae tendinae. These muscles prevent the valves from falling too far back when they close. [24] During the relaxation phase of the cardiac cycle, the papillary muscles are also relaxed and the tension on the chordae tendineae is slight.
The left posterior fascicle transmits impulses to the papillary muscles, leading to mitral valve closure. As the left posterior fascicle is shorter and broader than the right, impulses reach the papillary muscles just prior to depolarization, and therefore contraction, of the left ventricle myocardium.
Papillary muscles are finger-like projections from the wall of the left ventricle. When the left ventricle contracts, the pressure in the ventricle forces the valve to close, while the tendons keep the leaflets coapting together and prevent the valve from opening in the wrong direction (thus preventing blood flowing back to the left atrium).