300898 Lecture Notes - Lecture 2: Appendicular Skeleton, Hydrostatic Skeleton, Endoskeleton
Document Summary
The endoskeleton is the internal support structure of an animal, composed of mineralised tissue and is typical of vertebrate. Endoskeletons vary in complexity from functioning purely for support (as in the case of sponges), to serving as an attachment site for muscles and a mechanism for transmitting muscular forces. Pliant skeletons are capable of movement; thus, when stress is applied to the skeletal structure, it deforms and then reverts to its original shape. This skeletal structure is used in some invertebrates, for instance in the hinge of bivalve shells or the mesoglea of cnidarians such as jelly sh. Pliant skeletons are bene cial because only muscle contractions are needed to bend the skeleton; upon muscle relaxation, the skeleton will return to its original shape. Cartilage is one material that a pliant skeleton may be composed of, but most pliant skeletons are formed from a mixture of protein, polysaccharides, and water.
