mesoderm

Examples of mesoderm in the following topics:

• Animal Characterization Based on Features of Embryological Development

  • The pseudocoelomates have a coelom derived partly from mesoderm and partly from endoderm.
  • These pouches eventually fuse to form the mesoderm, which then gives rise to the coelom.
  • Triploblasts develop a third layer, the mesoderm, between the endoderm and ectoderm
  • Eucoelomates have a body cavity within the mesoderm, called a coelom, which is lined with mesoderm.
  • In deuterostomes, the mesoderm pinches off to form the coelom in a process called enterocoely.

• Organogenesis

  • Organogenesis is the process by which the three germ tissue layers of the embryo, which are the ectoderm, endoderm, and mesoderm, develop into the internal organs of the organism.
  • The mesoderm that lies on either side of the vertebrate neural tube will develop into the various connective tissues of the animal body .
  • A spatial pattern of gene expression reorganizes the mesoderm into groups of cells called somites, with spaces between them.
  • The mesoderm also forms a structure called the notochord, which is rod-shaped and forms the central axis of the animal body.
  • The mesoderm aids in the production of cardiac muscles, skeletal muscle, smooth muscle, tissues within the kidneys, and red blood cells.

• Gene Expression for Spatial Positioning

  • The mesoderm that lies on either side of the vertebrate neural tube will develop into the various connective tissues of the animal body.
  • A spatial pattern of gene expression reorganizes the mesoderm into groups of cells called somites with spaces between them.
  • The mesoderm also forms a structure called the notochord, which is rod-shaped and forms the central axis of the animal body.

• Cleavage, the Blastula Stage, and Gastrulation

  • The three germs layers are the endoderm, the ectoderm, and the mesoderm.
  • The ectoderm gives rise to the nervous system and the epidermis; the mesoderm gives rise to the muscle cells and connective tissue in the body; and the endoderm gives rise to columnar cells found in the digestive system and many internal organs.
  • The three germ layers give rise to different cell types in the animal body: the ectoderm forms the nervous system and the outer layer of skin, the mesoderm gives rise to muscles and connective tissues, and the endoderm gives rise to the lining of the digestive system and other internal organs.

• Superphylum Lophotrochozoa

  • In protostomy, solid groups of cells split from the endoderm or inner germ layer to form a central mesodermal layer of cells.
  • The lophotrochozoans are triploblastic, possessing an embryonic mesoderm sandwiched between the ectoderm and endoderm found in the diploblastic cnidarians.

• Cellular Differentiation

  • A pathway that is guided by the cell adhesion molecules is created as the cellular blastomere differentiates from the single-layered blastula to the three primary layers of germ cells in mammals, namely the ectoderm, mesoderm and endoderm (listed from most distal, or exterior, to the most proximal, or interior).
  • The ectoderm ends up forming the skin and the nervous system, the mesoderm forms the bones and muscular tissue, and the endoderm forms the internal organ tissues.

• Phylum Platyhelminthes

  • Flatworms have three embryonic tissue layers that give rise to surfaces that cover tissues (from ectoderm), internal tissues (from mesoderm), and line the digestive system (from endoderm).
  • The mesodermal tissues include mesenchymal cells that contain collagen and support secretory cells that secrete mucus and other materials at the surface.

• Phylum Annelida

  • This metamerism is thought to arise from identical teloblast cells in the embryonic stage, which develop into identical mesodermal structures.
  • Annelids show the presence of a true coelom, derived from embryonic mesoderm and protostomy.

• Gene Expression in Stem Cells

  • In a developing embryo, stem cells can differentiate into all of the specialized cells (including ectoderm, endoderm and mesoderm cells) but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues .

• Phylum Nematoda

  • The Nematoda, similar to most other animal phyla, are triploblastic, possessing an embryonic mesoderm that is sandwiched between the ectoderm and endoderm.