The pathogenesis of HIE in the newborn period involves the same key players that are also present in adults, namely energy crisis from hypoxia-ischemia, lactic acidosis, excitotoxicity, and free radicals, but there are some important modifiers, which account for different patterns of pathology in newborn babies.
Chordates (phylum Chordata) are a group of animals that includes all the vertebrates (subphylum Vertebrata), as well as two subphylum of invertebrates, the Urochordata (tunicates) and the Cephalochordata (lancelets).lso, the relationships of some chordate groups are not very well understood. 1  Phylum Chordata. 2  Subphylum Urochordata (Tunicates). 3  Subphylum Cephalochordata (Lancelets). 4  Class Myxini or Hyperotreti (hagfish). 5  Subphylum Vertebrata (Vertebrates-animals with backbones). 6  Class Conodonta (Conodonts).
By Phil Myers. Chordates are defined as organisms that possess a structure called a notochord, at least during some part of their development. The notochord is a rod that extends most of the length of the body when it is fully developed. Lying dorsal to the gut but ventral to the central nervous system, it stiffens the body and acts as support during locomotion. Other characteristics shared by chordates include the following (from Hickman and Roberts, 1994):