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).
Chordata, phylum Chordata-comprises true vertebrates and animals having a notochord. cephalochordate-fish-like animals having a notochord rather than a true spinal column. tunicate, urochord, urochordate-primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva.. Any of numerous animals of the phylum Chordata, having at some stage of development a dorsal nerve cord, a notochord, and gill slits and including all vertebrates, the hagfishes, and certain marine animals such as the lancelets and the tunicates.