-ärˌtirēˈōsəs noun
( plural coni arterio·si -ˌsī, -(ˌ)sē)
Etymology: New Latin, literally, arterial cone
1. : a prolongation of the ventricle of amphibians and certain fishes that is equipped with a spiral valve by which venous blood going to the pulmocutaneous arteries is separated from arterial blood going to the aorta and systemic arteries
2. : a conical prolongation of the right ventricle in man and mammals from which the pulmonary arteries emerge