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. 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.
The following chart shows the products produced by the endoderm.
Layer Category System General 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.
The Endoderm has differentiated into distinguishable organs as early as 5 weeks of embryonic development.
- ^ Langman's Medical Embryology, 11th edition. 2010.
- ^ The General category denotes that all or most of the animals containing this layer produce the adjacent product.
- ^ 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.
Developmental biology > Human embryogenesis (development of embryo) and development of fetus (TE E2.0) First three
weeksWeek 1Week 2
Human cell types / list derived primarily from endoderm ForegutCentroacinar cell · Pancreatic stellate cell Pharyngeal pouch Hindgut/cloacaUrothelial cells
Wikimedia Foundation. 2010.