The mesoderm gives rise to all the following structure in the fully developed fetus, except
A. Gonads
B. Nervous System
C. Circulatory system
D. Muscular system
Correct Answer: B. Nervous System
Explanation
Question:
The mesoderm gives rise to all the following structures in the fully developed fetus, except — explain.
Understanding the Mesoderm
The mesoderm is the middle germ layer formed during gastrulation. It mainly forms supporting, connective, muscular, and circulatory structures of the body.
Structures Derived from Mesoderm
Mesoderm gives rise to:
- Musculoskeletal system
- Bones
- Cartilage
- Muscles (skeletal, cardiac, smooth)
- Cardiovascular system
- Heart
- Blood
- Blood vessels
- Lymphatic system
- Urogenital system
- Kidneys
- Ureters
- Gonads (testes, ovaries)
- Reproductive ducts
- Connective tissues
- Dermis of skin
- Fascia
- Tendons and ligaments
- Serous membranes
- Peritoneum
- Pleura
- Pericardium
Structure NOT Derived from Mesoderm (Correct “EXCEPT”)
Structures derived from other germ layers, not mesoderm, include:
Nervous system → Ectoderm
- Brain
- Spinal cord
- Peripheral nerves
Epithelial lining of gastrointestinal tract → Endoderm
- Stomach lining
- Intestinal epithelium
Correct Answer (EXCEPT):
Nervous system (or any structure of neural origin)
Summary Table
Germ Layer Major Derivatives Ectoderm Nervous system, skin epidermis Mesoderm Muscles, bones, blood, kidneys Endoderm Gut epithelium, lungs, liver
Key Exam Point 📝
If options include brain, spinal cord, nerves, epidermis, or gut epithelium, they are NOT mesodermal and are the correct “except” choice.
Other Options Details
This question is based on embryological germ layer derivatives, especially the mesoderm.
Question idea
The mesoderm gives rise to all of the following structures in the fully developed fetus, EXCEPT —
A. Gonads ✅ (Mesoderm-derived)
- Gonads (testes and ovaries) develop from intermediate mesoderm.
- The intermediate mesoderm also forms:
- Kidneys
- Ureters
- Reproductive ducts
- So, gonads are mesodermal in origin.
B. Nervous System ❌ (NOT mesoderm-derived)
- The nervous system develops from ectoderm, not mesoderm.
- Specifically:
- Neural tube → brain and spinal cord
- Neural crest cells → peripheral nerves, autonomic ganglia, melanocytes
- This is the correct “EXCEPT” answer.
C. Circulatory System ✅ (Mesoderm-derived)
- The circulatory system arises from lateral plate mesoderm.
- It forms:
- Heart
- Blood vessels
- Blood cells
- Clearly a mesodermal derivative.
D. Muscular System ✅ (Mesoderm-derived)
- Muscles develop from paraxial mesoderm (somites).
- Includes:
- Skeletal muscles
- Cardiac muscle
- Smooth muscle
- Hence, muscular system is mesodermal.
✅ Correct Answer: B. Nervous System
Quick memory tip:
- Ectoderm → Nervous system, skin
- Mesoderm → Muscle, bone, blood, gonads
- Endoderm → Gut lining, lungs, liver
I hope that you liked this article.
Thanks!! 🙏 😊
Writer: Vandita Singh, Lucknow (GS India Nursing Group