Endoderm

Endoderm
Organs derived from endoderm.
Blastodermic vesicle of Vespertilio murinus. (Endoderm labeled as 'entoderm'.)
Gray's subject #6 49
Days 16
Precursor hypoblast
Gives rise to splanchnopleure
MeSH Endoderm

Endoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer), with the endoderm as the intermost layer.[1] Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm.

The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial lining of multiple systems.

Contents

Production

The following chart shows the products produced by the endoderm.

Layer Category System
General[2] Gastrointestinal tract. the entire alimentary canal except part of the mouth, pharynx and the terminal part of the rectum (which are lined by involutions of the ectoderm), the lining cells of all the glands which open into the digestive tube, including those of the liver and pancreas
General Respiratory tract the trachea, bronchi, and alveoli of the lungs
General Endocrine glands and organs the lining of the follicles of the thyroid gland and thymus
Auditory system the epithelium of the auditory tube and tympanic cavity
Urinary system the urinary bladder and part of the urethra

Liver and pancreas cells are believed to derive from a common precursor.[3]

The Endoderm has differentiated into distinguishable organs as early as 5 weeks of embryonic development.

Additional images

See also

References

  1. ^ Langman's Medical Embryology, 11th edition. 2010.
  2. ^ The General category denotes that all or most of the animals containing this layer produce the adjacent product.
  3. ^ Zaret KS (October 2001). "Hepatocyte differentiation: from the endoderm and beyond". Curr. Opin. Genet. Dev. 11 (5): 568–74. doi:10.1016/S0959-437X(00)00234-3. PMID 11532400. http://linkinghub.elsevier.com/retrieve/pii/S0959-437X(00)00234-3. 
First three
weeks
Week 1
Week 2
(Bilaminar)
Week 3
(Trilaminar)
Endoderm

M: OBS

phys/devp/memb

mthr/fetu/infc, epon

proc, drug(2A/G2C)
Human cell types / list derived primarily from endoderm
Foregut
Pharyngeal pouch
Hindgut/cloaca

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 As such, some of the information contained within it may be outdated.