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).
Phylum Chordata is the only phylum where all the members have a  backbone.   However, there is more to it than that, especially given that there  are two invertebrate ch â¦ ordate groups-Urochordata (tunicates) and  Cephalachordata (lancelets) - whose backbone is not in the form of  actual vertebrae.