Concept: This question tests your knowledge of the anatomy of the human spinal cord, specifically its terminal structures.

Why (B) is correct: The spinal cord tapers off into a cone-shaped structure called the conus medullaris, typically located at the level of the first or second lumbar vertebra (L1 or L2) in adults. This is the true anatomical end of the spinal cord proper.

Why other options are wrong:

• (A) Cauda equina: This refers to the bundle of spinal nerves (lumbar, sacral, and coccygeal) that extend inferiorly from the conus medullaris, resembling a horse's tail. It is not the terminal part of the spinal cord itself.
• (C) Filum terminale: This is a thin, fibrous extension of the pia mater that extends from the apex of the conus medullaris to anchor the spinal cord to the coccyx. It is a connective tissue filament, not nervous tissue.
• (D) Medulla oblongata: This is the lowest part of the brainstem, continuous with the spinal cord superiorly, not its terminal inferior end.

Common Mistake: Students often confuse the conus medullaris, filum terminale, and cauda equina, as they are all located in the terminal region of the vertebral canal.

NEET Tip / Mnemonic: Remember that the Conus Medullaris is the Cone-shaped Main end of the spinal cord.

Correct Answer: (B)