INBDE (Integrated National Board Dental Examination) Practice Exam

The skin, brain, neck, and nerves came from what germ layer?

1. Ectoderm

2. Mesoderm

3. Endoderm

4. Mesenchyme

The correct answer is: Ectoderm

The skin, brain, neck, and nerves are derived from the ectoderm germ layer. The ectoderm is one of the three primary germ layers formed during gastrulation in the early stages of embryonic development. It gives rise to structures such as the epidermis (outer layer of skin), central and peripheral nervous systems (including the brain and nerves), and various epithelial tissues. Mesoderm gives rise to structures such as muscle, bone, blood, and connective tissues. Endoderm gives rise to the lining of the digestive tract and associated organs such as the liver and pancreas. Mesenchyme is a type of unspecialized connective tissue that is formed from mesoderm and can give rise to various tissues and organs, but it is not a specific germ layer in embryonic development like ectoderm, mesoderm, and endoderm.