Endoderm is made up of which structures?

Endoderm is made up of which structures?

• A. Musculature and connective tissue
• B. Majority of gut, epithelium, glands
• C. Nervous system only
• D. Epidermis

Answer: (B)

Endoderm forms the internal lining and glands associated with the gut and airway. Specifically, it gives rise to the epithelium of the gastrointestinal and respiratory tracts and the secretory organs connected to them, such as the liver, pancreas, and biliary system. This distinguishes endoderm from other germ layers: musculature and connective tissue come from the mesoderm, the nervous system mainly from the ectoderm, and the epidermis from the ectoderm. So the structures described as the gut epithelium and its glands are endodermal in origin.

Endoderm forms the internal lining and glands associated with the gut and airway. Specifically, it gives rise to the epithelium of the gastrointestinal and respiratory tracts and the secretory organs connected to them, such as the liver, pancreas, and biliary system. This distinguishes endoderm from other germ layers: musculature and connective tissue come from the mesoderm, the nervous system mainly from the ectoderm, and the epidermis from the ectoderm. So the structures described as the gut epithelium and its glands are endodermal in origin.