Question

Spleen develops from

• A. Ectoderm
• B. Mesoderm
• C. Endoderm
• D. None of the above

Answer 1

Answer: (B)

Mesoderm

The three germ layers (the ectoderm, the mesoderm and the endoderm) are in place at the end of gastrulation and gives rise to different parts.
The ectoderm gives rise to central nervous system (brain and spinal cord), the peripheral nervous system, the sensory epithelia of the eye, ear and nose, the epidermis, mammary gland, pituitary gland.
The mesoderm gives rise to connective tissue (cartilage and bone), striated and smooth muscles, the heart walls, blood and lymph vessels and cells, kidneys, gonads and genital ducts, spleen.
The endoderm gives rise to the epithelial lining of the gastrointestinal and respiratory tract; the parenchyma of tonsils, liver, thymus, thyroid, parathyroids and pancreas; the epithelial lining of the urinary bladder and urethra.