am-PULL-ee The enlarged bases of the semicircular canals in the inner ear, lined with hair cells that detect fluid movement and convert it into action potentials. 655
the enlarged end of a tube or canal, used to refer to the enlarged ends of echinoderm tube feet, an enlargement at the end of the semicircular canals of the inner ear of vertebrates, or, more generally, the dilated end of a vessel or duct.