Skeleton
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This page is part of the EvoWiki Encyclopedia of Anatomy and Physiology. |
The skeleton refers to the system that functions in physically supporting the body of an organism.
Structural Morphology
Vertebrates have an endoskeleton made of bones or cartilage; arthropods and some other invertebrates (such as Mollusca) have a chitinous exoskeleton and both Cnidarians and Annelida have a hydrostatic skeleton (using pressurised fluid rather than hardened structures).
Vertebrate Endoskeleton
The skeleton of vertebrates can be divided into two sections:
Axial skeleton:
Appendicular Skeleton:
Arthropod Exoskeleton
The exoskeleton of arthropods can usually be divided into discrete sections, or tagmata (singular: tagma). Generally, there three tagmata, some of which may fused in some orders. Insects and Trilobites have 3 distinct tagmata, whereas spiders, scorpions and crustaceans have only two obvious tagmata (the anterior two of the three being fused).
