Question

What is the source of coelomic fluid?

Answer 1

Hint: The word ‘coelom’ refers to the body cavity present in most of the animals. It is positioned in such a manner that it surrounds and contains the digestive tract and other organs of the body. The fluid-filled in the coelom is called coelomic fluid.

Complete answer: The word ‘coelom’ is derived from the Greek word meaning cavity. The mesodermal lined cavity present between the gut and the outer body wall is called coelom. During the period of embryo development, the formation of coelom begins in the gastrulation stage. A blind pouch called archenteron is formed by the developing digestive tube of the embryo. Archenteron is the primary gut formed during the development of the embryo. The mesoderm layer splits into two layers called ectoderm and endoderm. The ectoderm forms the parietal layer whereas the endoderm forms the inner lining of the alimentary canal called the visceral layer. The space present between the visceral layer and the parietal layer is called a body cavity or coelom. The fluid-filled in the coelom is called coelomic fluid. The source of coelomic fluid is the mesodermal tissues. Coelomic fluid carries out many functions such as shock absorber, transport of nutrients, gases, and waste products around the body. It acts as a storage for sperm and egg during the maturation period. The coelomic fluid in the body is circulated by the contraction of muscles in the body or by mesothelial cells.

Note: In some animals, the coelom is lined with mesothelium. In animals belonging to the Molluscs, it is undifferentiated. Depending upon the presence of a body cavity or coelom animals are classified as coelomate and acoelomate.