Phylum Chordata

Term Paper # 100308

Biology > Zoology

Phylum Chordata

A look at evolutionary trends in phylum chordata (sea squirts and vertebrate animals).

3,467 words () | 12 sources | MLA | 2003 Canada

Paper Summary:

This paper provides an explanation of the evolutionary development of the circulatory, respiratory, digestive, sensory, and integumentary systems of phylum chordata. Comparisons between the systems various classes of phylum chordata are made, and the evolutionary advantages of the higher classes are highlighted. The paper is also accompanied with relevant diagrams and figures.

Outline:
Circulatory System
Evolution of the Heart
Piscine Heart
Amphibian and Reptilian Hearts
Avian and Mammalian Hearts
Respiratory System
Respiration in Agnatha and Chondrichthyes (Gills)
Respiration in Osteichthyes (Gills)
Respiration in Amphibians (Gills, Skin, Lungs)
Respiration in Reptiles, Birds, and Mammals (Lungs)
Digestive System
General Trends in Evolution of the Digestive System
Ruminant Stomach
Avian Gizzard
Sensory System
Usage of Olfactory System and Usage of Visual System
Prevertebrates: An Introduction
Anamniotes
Amniotes
Integumentary System
Anamniotes
Amniotes

From the Paper:

"One of the most fascinating developments made by the vertebrates was the heart. The complex and efficient four-chambered pumping mechanism possessed by mammals and birds evolved from what was only a muscular artery in protochordates. The heart itself is a specialized muscle responsible for circulating blood through the blood-vascular network. Marine protochordates possessed little more than a muscular region near the base of the aorta because, virtually anywhere on their bodies, they were capable of exchanging O2 and CO2 through their relatively thin skin. When scales and thicker skin emerged, however, this capability was lost, and respiration was localized in the pharyngeal region. An effective pumping device was required, and thus, the heart evolved."

Sample of Sources Used:

Armbruster, Jon. "Comparative Anatomy Topic 12: The Circulatory System." Comparative Anatomy - BIOL 3010. <http://www.auburn.edu/academic/classes/ zy/0301/Topic12/Topic12.html>. (Sept. 2, 2003).
Campbell, Jonathan A. "Digestive System." Comparative Vertebrate Anatomy. <http://www.uta.edu/biology/campbell/cva/3452dig.htm>. (Sept. 2, 2003).
Clark, Dahl. "The Evolution of the Vertebrate Brain." Essays on Science.<http://www.duke.edu/~dbc4/resonance/literature/essays/sci/evolverb.htm>. (Sept. 2, 2003)
"Comparative Anatomy." Microsoft(r) Encarta(r) Encyclopedia 2001. (c) 1993-2000 Microsoft Corporation. All rights reserved.
Dunbrack. "Sect. 2. Agnatha, The Jawless Vertebrates." Course Notes for Biology 2210. <http://www.ucs.mun.ca/~dunbrack/2210agnatha.html>. (Sept. 2, 2003).