|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
mesoderm
mesoderm In a triploblastic embryo, the middle layer of cells, which form a hollow ring surrounding the endoderm, giving rise to muscle, blood vessel, some nervous tissue, and the organs of the body within the mesoderm cavity. On development of the notochord, the mesoderm develops bilaterally paired blocks on either side of the notochord, known as somites, in which voluntary muscles, vertebrae, and deep portions of the skin develop. Somites are connected by undifferentiated mesoderm, known as lateral plate mesoderm. The ectodermal layer of the mesoderm is called the somatic mesoderm and the endodermal layer is called the splanchnic mesoderm layer. The mesoderm region between the somite and lateral plate mesoderm eventually separates and forms a nephric ridge which will develop into the kidney. A genital ridge later forms from the medial border of the kidneys which gives rise to the gonads. After differentiation of the mesoderm, organogenesis occurs.
|
|
|
Cite this article
MICHAEL ALLABY. "mesoderm." A Dictionary of Zoology. 1999. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "mesoderm." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O8-mesoderm.html MICHAEL ALLABY. "mesoderm." A Dictionary of Zoology. 1999. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-mesoderm.html |
|
mesoderm
mesoderm in biology, middle layer of tissue formed in the gastrula stage of the developing embryo. At the end of the blastula stage, cells of the embryo are arranged in the form of a hollow ball. Continued cell movement results in an invagination of the bottom region of the embryo, producing a form that resembles a double-layered cup. A third layer, the mesoderm, is formed between the other two by growth of cells derived from a marginal zone. The mesoderm is the germ layer that forms many muscles, the circulatory and excretory systems, and the dermis, skeleton, and other supportive and connective tissue. It also gives rise to the notochord , a supporting structure between the neural canal and the primitive gut. In many animals, including vertebrates, the mesoderm surrounds a cavity known as the coelom , the space that contains the viscera. See embryo . |
|
|
Cite this article
"mesoderm." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "mesoderm." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1E1-mesoderm.html "mesoderm." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-mesoderm.html |
|
mesoderm
mes·o·derm / ˈmezəˌdərm; ˈmē-/ • n. Embryology the middle layer of an embryo in early development, between the endoderm and ectoderm. DERIVATIVES: mes·o·der·mal / ˌmezəˈdəməl; mē-/ adj. mes·o·der·mic / -ˈdərmik/ adj. |
|
|
Cite this article
"mesoderm." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "mesoderm." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O999-mesoderm.html "mesoderm." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-mesoderm.html |
|
mesoderm
mesoderm The layer of cells in the gastrula that lies between the ectoderm and endoderm. It develops into the muscles, circulatory system, and sex organs and in vertebrates also into the excretory system and skeleton. See also germ layers.
|
|
|
Cite this article
"mesoderm." A Dictionary of Biology. 2004. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "mesoderm." A Dictionary of Biology. 2004. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O6-mesoderm.html "mesoderm." A Dictionary of Biology. 2004. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-mesoderm.html |
|
mesoderm
mesoderm (mes-oh-derm) n. the middle germ layer of the early embryo. It gives rise to cartilage, muscle, bone, blood, kidneys, gonads and their ducts, and connective tissue.
—mesodermal adj. |
|
|
Cite this article
"mesoderm." A Dictionary of Nursing. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "mesoderm." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O62-mesoderm.html "mesoderm." A Dictionary of Nursing. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-mesoderm.html |
|
|
Search over 100 encyclopedias and dictionaries:
HighBeam™ Research, Inc. © Copyright 2012. All rights reserved.
The Encyclopedia.com advertising network includes:
