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.
C. Pharyngeal pouches. D. Endostyle-elongated groove in the pharynx floor of protochordates that may develop as the thyroid gland in chordates. These four characteristics may be found in some of the ancestors of chordates and are commonly placed in an informal grouping called Protochordates.These serve as living representations of the missing fossils in vertebrate evolution.n contrast to protochordates (hemichordates, urochordates, and cephalochordates), vertebrates are actively-feeding, predatory organisms that move by lateral undulation of an elongate body. Hemichordates and most urochordates are also filter-feeders, moving water through their gill slits, but are sessile as adults.