MICROANATOMY

Detailed explanation-1: -The body cavity, which is lined by mesoderm is called coelom. Animals possessing such a coelom are called coelomates. Examples include the annelids, molluscs, arthropods, echinoderms, hemichordates and chordates.

Detailed explanation-2: -Coelomate animals or Coelomata (also known as eucoelomates – “true coelom") have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm (one of the three primary tissue layers).

Detailed explanation-3: -Coelomates are animals with a fluid-filled body cavity lined with tissue derived from the mesoderm germ layer. This lined body cavity is called a true coelom (Fig. 3.17 B). Coelomates are represented by many animal phyla including the Mollusca, Annelida, Arthropoda, Echinodermata, and Chordata.

Detailed explanation-4: -The protostome coelomates (acoelomates and pseudocoelomates are also protostomes) include the mollusks, annelids, arthropods, pogonophorans, apometamerans, tardigrades, onychophorans, phoronids, brachiopods, and bryozoans. Deuterostomes include the chaetognaths, echinoderms, hemichordates, and chordates.

Detailed explanation-5: -A coelom is a fluid-filled body cavity found in some animals that acts as a cushion for the internal organs. These animals are referred to as coelomates or eucoelomates, that is those animals with a true coelom.