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).
There are three subphyla in the chordates-one, the vertebrates, will be covered next chapter. The other two have chordate features but no backbones: The sea squirts or tunicates (technically, urochordates) spend their adult live as sessile creatures, looking like a vase with two openings.here are three subphyla in the chordates-one, the vertebrates, will be covered next chapter. The other two have chordate features but no backbones: The sea squirts or tunicates (technically, urochordates) spend their adult live as sessile creatures, looking like a vase with two openings.