sinoatrial node molecular composition trait sinoatrial node ribonucleic acid amount CMO:0003985 caripark pacemaker RNA amount pacemaker ribonucleic acid amount The proportion, quantity, or volume of ribonucleic acid in the small mass of modified cardiac muscle fibers located at the junction of the superior vena cava and the right atrium that is the source of contraction impulses for the heart. Ribonucleic acid is a high molecular weight, linear polymer composed of nucleotides containing ribose and linked by phosphodiester bonds. SA node ribonucleic acid amount SA node RNA amount 2024-04-15T13:34:29Z VT:0011113 sinoatrial node RNA amount Trait.ontology