Question

Nervous system of human being is derived from

• A. Ectoderm
• B. Mesoderm
• C. Endoderm
• D. Trophoblast

Answer 1

The correct option is A Ectoderm

The germ layers represent some of the first lineage-specific stem cells (e.g., cells destined to contribute to specific types of tissue, such as muscle or blood) in embryonic development. Hence, each germ layer eventually gives rise to certain tissue types in the body.
Ectoderm is one of the three primary germ layers in the very early embryo which gives rise to the following tissues.
$\begin{array}{ccc}\text{Ectoderm}& \text{Mesoderm}& \text{Endoderm}\\ \ast \text{Epidermis of skin and its derivatives}& \ast \text{Muscles: smooth, cardiac, and}& \ast \text{Epithelial lining of the gastrointestinal}\\ \text{such as hair, nails, sweat and}& \text{skeletal}& \text{tract (GIT)}\\ \text{sebaceous glands}& & \\ \ast \text{Epithelial lining of}& \ast \text{Bones and cartilages}& -\text{Respiratory tract}\\ -\text{Lower part of the anal canal}& \ast \text{Connective tissue}& -\text{Urinary tract}\\ -\text{Distal part of the male urethra}& \ast \text{Heart, blood vessels, and lymph vessels}& -\text{Biliary tract}\\ -\text{Lower part of the vagina}& \ast \text{Epithelial lining of blood vessels, lymph}& -\text{Auditory tube and middle ear cavity}\\ -\text{External auditory meatus}& \text{vessels, body cavities, and joint cavities}& -\text{Uterus and upper part of vagina}\\ -\text{Oral cavity}& \ast \text{Spleen}& \ast \text{Liver(Hepatocytes)}\\ -\text{Nasal cavity}& \ast \text{Kidney and ureters}& \ast \text{Pancreas(acinar and islet cells)}\\ \ast \text{Lens of eye}& \ast \text{Adrenal cortex}& \ast \text{Thyroid(follicular cells)}\\ \ast \text{Enamel of teeth}& \ast \text{Testes and ovaries}& \ast \text{Parathyroid (principle and oxyphil cells)}\\ \ast \text{Adenohypophysis of the pituitary gland}& & \\ \ast \text{Adrenal medulla}& & \\ \ast \text{Nervous tissue and sense organs}& & \end{array}$