BIOL10005 Lecture Notes - Spring 2018 Lecture 13 - Anatomical terms of location, Mantle (mollusc), Bivalvia
20 Sep 2018
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Document Summary
Closed vascular system acts as a uid lled hydrostatic skeleton. Segmented worms of soil, marine or freshwater habitats. Serial repetition of function units (compared with atworms) Can occur in middle and outer layers of tissue. Aquatic and terrestrial forms widespread except madagascar and antarctica. Pressure di erences are responsible for changes in shape along the worm"s body, allowing worms to crawl and burrow for both escape and foraging. the body surface and transports food materials, hormones and excretory substances around the body. A vascular system augments simple di usion of oxygen and carbon dioxide across. The respiratory pigment of annelids is commonly erythrocruorin. Oxygenation of blood occurs at or near the epidermis and specialised gas- exchange organs, such as gills, have developed in marine polychaete worms, molluscs and crustaceans. The coelomic space separates the internal organs from the body wall so that gut and body wall movements can be relatively independent.
