connects connects develops from develops from cardiac valve embryonic structure endocardial cushion sinus venosus cardiac atrium sinoatrial valve sinoatrial valves in humans and mouse this is the opening from SV into right atrium. This class represents the valve connecting the SV to any atrium and is applicable to animals with a single atrium UBERON:0002086 sinuatrial valve A valve at the opening of the sinus venosus into the primordial atrium[TFD,modified]. ZFA:0000680 FMA:71120 TAO:0000680