Trabeculae lie at the interface between intracardiac flow and the compact myocardium. Their fractal branching pattern helps to maintain cardiac performance in both healthy and failing hearts by increasing
contractility and
stroke work. Trabecular morphology is also important to intraventricular conduction, suggesting these complex structures are involved in cardiac electrophysiology as well as mechanical function. A condensation of trabecular fibres forms the moderator band which carries the right branch of the
bundle of His. The trabeculae carneae also serve a function similar to that of
papillary muscles in that their contraction pulls on the
chordae tendineae, preventing inversion of the
mitral (bicuspid) and
tricuspid valves towards the atrial chambers, which would lead to
subsequent leakage of the blood back into the atria. By this action on the
atrioventricular valves, backflow of the blood from the ventricles into the atria is prevented. 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. Trabeculae ratios of capillary-to myocyte differ between the walls of the right and left ventricle. In the left ventricle, each capillary delivers oxygen to one myocyte. However, in the right ventricle the capillary-to myocyte ratio is 0.8 because the right ventricle tissues have a lower oxygen consumption due to a weaker afterload. ==See also==