Aortic insufficiency (AI), also known as aortic regurgitation (AR), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle.
Definition of echidna. : a spiny-coated toothless burrowing nocturnal monotreme mammal (Tachyglossus aculeatus) of Australia, Tasmania, and New Guinea that has a long extensible tongue and long heavy claws and that feeds chiefly on ants; also : a related mammal (Zaglossus bruijni) of New Guinea having a longer snout and shorter spines.
Spiny anteater is a nickname for the echidna. They are not anteaters at all, but monotremes, or egg-laying mammals. Echidnas are found throughout most of Australia, and are â¦ highly adaptable to a wide range of environments, which has been one of the reasons why they are not threatened by habitat loss.es. The spiny anteater, more correctly known as the echidna, is a monotreme. This means it is an egg-laying mammal which feeds its young on mothers' milk, one of only two such types of animals in the world.