Lateral plate mesoderm
Transverse section of a chick embryo of forty-five hours’ incubation. * Chordamesoderm: yellow, at notochord. * Paraxial mesoderm: red, at somite. * Intermediate mesoderm: purple, near Wolffian duct. * Lateral plate mesoderm: purple, near "Somatic mesoderm" and "Splanchic mesoderm".
Model of human embryo 1.3 mm. long.. (Splanchic mesoderm labeled at left, somatic mesoderm at top right.)
Gray's	subject #6 50
Carnegie stage	9
Precursor	mesoderm
Gives rise to	somatopleure, splanchnopleure

Lateral plate mesoderm is a type of mesoderm that is found at the periphery of the embryo.

Contents 1 Division into layers 2 Serosal mesoderms 3 Cavities 4 See also 5 External links 6 References

[edit] Division into layers

It will split into two layers, the somatic layer/mesoderm and the splanchnic layer/mesoderm

• The somatic layer forms the future body wall.
• The splanchnic layer forms the circulatory system and future gut wall.

Spaces within the lateral plate are enclosed and forms the intraembryonic coelom.

It is formed by the secretion of BMP-4 by the ectoderm.^[1]

[edit] Serosal mesoderms

Lateral plate mesoderm gives rise to the serosal mesoderms.^[2]

• forms a ventral layer associated with endoderm, the splanchnopleuric mesoderm. This forms the viscera and heart
• forms a dorsal layer associated with ectoderm, the somatopleuric mesoderm. This forms the body wall lining and dermis.
• Abdominal portion becomes contained in dorsal mesentery, part of the serosal mesoderm.
• When the two layers form, a cardiogenic plate is visible. Later, this will form the myocardial primordium, which will contribute to the tubular heart.

[edit] Cavities

In the 4th week the coelom divides into pericardial, pleural and peritoneal cavities.^[2]

• First partition: is the septum transversum.

• This will be translocated later into the diaphragm and ventral mesentery.
• Divides the coelom into primitive pericardial and peritoneal cavities

• pleuropericardial folds appear on the lateral wall of primitive pericardial cavity, which will eventually cause a partition to form the pericardial and pleural cavities.
• Communication between these partitions formed by the pericardioperitoneal canals. However, pleuroperitoneal membranes will grow to fuse with the septum transversum to close off these canals.

• At day 22, lung buds form, remaining ensheathed in a splachnopleuric mesoderm

[edit] See also

• Serous membrane

[edit] External links

• Swiss embryology (from UL, UB, and UF) hdisqueembry/triderm08
• Overview and diagram at palaeos.com
• Outline at csustan.edu

[edit] References

1. ^ Tonegawa A, Funayama N, Ueno N, Takahashi Y (1997). "Mesodermal subdivision along the mediolateral axis in chicken controlled by different concentrations of BMP-4". Development 124 (10): 1975–84. PMID 9169844. 
2. ^ ^{a b} Larsen, William J. (1998). Essentials of human embryology. Edinburgh: Churchill Livingstone. ISBN 0-443-07514-X. 

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

v • d • e Developmental biology > Human embryogenesis (development of embryo) and development of fetus First three weeks Week 1 Fertilization · Egg activation · Zygote · Cleavage · Morula · Blastula (Blastomere) · Blastocyst · Inner cell mass Week 2 (Bilaminar) Hypoblast · Epiblast Week 3 (Trilaminar) Germ layers Archenteron/Primitive streak (Primitive pit, Primitive knot/Blastopore, Primitive groove) · Gastrula/Gastrulation · Regional specification Ectoderm Surface ectoderm · Neuroectoderm · Somatopleure · Neurulation · Neural crest Endoderm Splanchnopleure Mesoderm Chorda- · Paraxial (Somite/Somitomere/Sclerotome/Myotome/Dermatome) · Intermediate · Lateral plate (Intraembryonic coelom, Splanchnopleure/Somatopleure) Extraembryonic/ uterus Trophoblast (Cytotrophoblast, Syncytiotrophoblast) Blastocoele · Yolk sack/exocoelomic cavity · Heuser's membrane · Extraembryonic coelom · Vitelline duct Umbilical cord (Umbilical artery, Umbilical vein, Wharton's jelly) · Allantois Placenta · Decidua (Decidual cells) · Chorionic villi/Intervillous space · Gestational sac (Amnion/Amniotic sac/Amniotic cavity, Chorion) Histogenesis Programmed cell death (Apoptosis) · Stem cells · Germ line development Organogenesis Limb development: Limb bud · Apical ectodermal ridge/AER other structures: Eye development · Cutaneous structure development · Heart development · Development of the urinary and reproductive organs (Some dates are approximate—see Carnegie stages and a timeline.)

This developmental biology article is a stub. You can help Wikipedia by expanding it. v • d • e