During the third week of embryonic development, cells migrating through the primitive streak form a hollow canal and a solid cord extending cranially from the primitive node. This structure eventually forms the:
- A Notochord ✓
- B Neural tube
- C Paraxial mesoderm
- D Intermediate mesoderm
Correct answer: A. Notochord
Explanation
The notochordal process forms from cells migrating cranially from the primitive node through the primitive streak. It develops a lumen, then collapses to form the solid notochord, which serves as the basis for the axial skeleton and induces neural plate formation. The neural tube forms later from the overlying ectoderm.
Reference: Langman's Medical Embryology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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