What organs arise from the endoderm?

1 Answer
Jul 22, 2014

There are three layers that form as an embryo develops. The ectoderm (outer layer), the mesoderm (middle layer) and the endoderm (inner layer).


What you see here is the ectoderm in orange, the endoderm in red and the mesoderm in black.

The endoderm layer forms the respiratory and digestive tracts. Actually, they begin as the respiratory and digestive tubes.

The digestive tube will finally form into 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.
(reference: Wikipedia)

The respiratory tube will finally form into the trachea, bronchi, and alveoli of the lungs, the lining of the follicles of the thyroid gland and thymus, the epithelium of the auditory tube and tympanic cavity, bladder and part of the urethra
(reference: Wikipedia)