-ˌspīˈralə̇s, -rāl-; spə̇ˈräl- noun
( plural valvulae spira·les -a(ˌ)lēz, -ā(ˌ)lēz, -ä(ˌ)lās)
Etymology: New Latin, literally, spiral valvula
: a series of crescentic folds of mucous membrane somewhat spirally arranged on the interior of the gallbladder and continuing into the cystic duct — called also valve of Heister