Mesoderm: Difference between revisions

Notice - Mark Hill

This page will contain the content required when attending the lecture. Currently this page is only a template and will be updated before the lecture (this notice removed when completed). Final lecture pages can also be printed out using the "printable version" lefthand menu.

Introduction

The trilaminar embryo

The middle layer of the early trilaminar embryo germ layers (ectoderm, mesoderm and endoderm) formed by gastrulation.

Some Recent Findings

Transcriptional profiling of the nucleus pulposus: say yes to notochord^[1]"This editorial addresses the debate concerning the origin of adult nucleus pulposus cells in the light of profiling studies by Minogue and colleagues. In their report of several marker genes that distinguish nucleus pulposus cells from other related cell types, the authors provide novel insights into the notochordal nature of the former. Together with recently published work, their work lends support to the view that all cells present within the nucleus pulposus are derived from the notochord. Hence, the choice of an animal model for disc research should be based on considerations other than the cell loss and replacement by non-notochordal cells."

Mesoderm Formation during Gastrulation

<Flowplayer width="390" height="510" autoplay="true">Mesoderm_001.flv</Flowplayer>

This animation shows the migration of mesoderm throughout the embryonic disc during gastrulation.

The pink arrow show how mesodermal cells spread out between the ectoderm and endoderm layers, forming the third layer of the trilaminar embryo.

Axial process - the arrow running from the primitive node upward is the axial process which will later form the notochord.

There are only 2 regions where no mesoderm is found: buccopharyngeal membrane and cloacal membrane.

these two regions form the upper and lower ends of the gastrointestinal tract.

Prechordal plate - lies above the buccopharyngeal membrane and is the cardiogenic mesoderm, that will form the heart.

Links: Gastrulation

Patterning

Notochord secreting sonic hedgehog, shown in white


Neural tube patterning	Somite patterning

Molecular Factors

References

↑ <pubmed>20497604</pubmed>

Reviews

Articles

Search PubMed

Search NLM Online Textbooks: "Mesoderm" : Developmental Biology | The Cell- A molecular Approach | Molecular Biology of the Cell | Endocrinology

Search Pubmed: Mesoderm | Notochord

External Links

Take the Quiz

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, April 23) Embryology Mesoderm. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Mesoderm

What Links Here?

@@ Line 63: / Line 63: @@
 ==External Links==
+==Take the Quiz==
+<quiz display=simple>
+{Mesenchyme refers to the middle layer of the trilaminar embryo
+|type="()"}
+- true
++ false
+|| The  the middle layer of the trilaminar embryo is the '''mesoderm''' (meaning middle layer), while most of these cells are mesemchymal in appearance, this term is used to describe the cell histological appearance/organization.
+{The intraembryonic coelom forms within :
+|type="()"}
+- somites
++ lateral plate
+- neural tube
+- intermediate mesoderm
+||The intraembryonic coelom forms initially small spaces  in the mesoderm layer and coalesce to form a single large "horseshoe-shaped" space within the '''lateral plate mesoderm''' around the embryonic disc. Both young somites (somitocoels) and the neural tube (neural tube lumen) do have cavities, but neither is called the intraembryonic coelom.
+{All paraxial mesoderm segments into somites.
+|type="()"}
+- true
++ false
+|| While somites do form within paraxial mesoderm, this region remains unsegmented at the level of the head and therefore does not incorporate into somites.
+{Somites are developmental structures that contribute the following adult structures :
+|type="()"}
+- vertebra, notochord, dermis, skeletal muscle
++ vertebra, intervertebral discs, dermis, skeletal muscle
+- kidney, body wall connective tissue, sensory ganglia
+- kidney, gastrointestinal tract smooth muscle, mesentry
+||Each somite has specific regions that contribute different components of the embryo. Sclerotome contributes the vertebral column ('''vertebra, intervertebral discs'''). Dermotome contributes the connective tissue layers of the skin ('''dermis''', hypodermis). Myotome ontributes the '''skeletal muscle''' of the body and limbs.
+</quiz>

	somites
	lateral plate
	neural tube
	intermediate mesoderm

	vertebra, notochord, dermis, skeletal muscle
	vertebra, intervertebral discs, dermis, skeletal muscle
	kidney, body wall connective tissue, sensory ganglia
	kidney, gastrointestinal tract smooth muscle, mesentry