Practice Essentials. Perinatal asphyxia, more appropriately known as hypoxic-ischemic encephalopathy (HIE), is characterized by clinical and laboratory evidence of acute or subacute brain injury due to asphyxia. The primary causes of this condition are systemic hypoxemia and/or reduced cerebral blood flow (CBF) (see the image below).
Chondrichthyes (/kÉnËdrÉªkÎ¸É¨.iËz/ ; from Greek ÏÎ¿Î½Î´Ï- chondr- 'cartilage', á¼°ÏÎ¸ÏÏ ichthys 'fish') is a class that contains the cartilaginous fishes: they are jawed vertebrates with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone.he skeleton is cartilaginous. The notochord, which is present in the young, is gradually replaced by cartilage. Chondrichthyes also lack ribs, so if they leave water, the larger species' own body weight would crush their internal organs long before they would suffocate.
The Chondrichthyes are the cartilaginous fishes including the sharks, rays, skates and chimaeras. The Osteichthyes are the bony fish. Both of these groups became established d â¦ uring the Devonian Period about 400 million years ago.The Chondrichthyes differ from the Osteichthyes in many respects, including their skeletons, scales, teeth, buoyancy, swimming, gills and reproduction. Scales:   Cartilaginous fish have large scales called placoid scales. These have a bone like base embedded in the skin and a backward projecting enamel covered dentine spine. The whole thing has a central pulp cavity (rather like the structure of teeth). The epidermis and dermis form placoid scales.