Thursday, January 6, 2011
Task 2 - Animalia, Vertebrate
What is a Vertebrate?
An animal with a backbone, or spinal column, made of interlocking units called vertebrae.
Swimming is a common and important component of vertebrate behavior.
Many vertebrates live in or near water, and most vertebrates can swim if necessary.
How the embryonic develops?
The zygote develops 3 germ layers:
The neural crest is the final germ layer that forms in the embryo.
All vertebrate embryos go through a pharyngeal stage where they have pharyngeal clefts which are precursors to gills.
In everybody but fish these disappear, but their linings give rise to many glands in the lymphatic system: thymus, tonsils, carotid bones, parathyroid glands
Axial Skeleton and Musculature
The notochord is the original “backbone” of all the chordates
Vertebrae or cartilage or bone surround and replace the notochord as it develops, although portions remain as intervertebral disks in adult tetrapods
The notochord is packed with incompressible fluid- filled vacuoles that make it rigid. It’s wrapped in a fibrous sheath and is the attahcment site for segmental muscles and connective tissues
The Nervous System
Vertebrates are unique in having a dual nervous system:
Somatic or Voluntary: innervates the limb muscles we consciously move and relays sensory information from the skin
Visceral or Involuntary: innervates organ muscles and the sensors that monitor things like blood pH.
Classification Of A Vertebrate
Vertebrate are from the groups of Fishes, Amphibians, Reptiles, Birds and Mammals
Fish, they are ectothermic, aquatic vertebrates.
Amphibians are ectothermic vertebrates.
Reptiles are ectothermic vertebrates.
Birds are endothermic vertebrates.
Mammals are endothermic vertebrates.
Posted by Jun Peng at 1/06/2011 10:31:00 PM