Conus medullaris is located around which vertebral level and affects which sacral segments?

Conus medullaris is located around which vertebral level and affects which sacral segments?

• A. Around L1; affects S2-S5
• B. Around T12; affects L1-L4
• C. Around L3; affects S1-S4
• D. Around C7; affects S0-S3

Answer: (A)

The main idea is where the spinal cord ends and which nerve roots come from that region. The conus medullaris is the tapered end of the spinal cord and, in adults, it sits around the L1 vertebral level. From this area originate the lower sacral nerve roots that innervate pelvic organs and perineal structures. Because those sacral roots lie in the conus region, a lesion here most directly affects sacral function, particularly the S2–S5 segments, which govern bladder and bowel control, sexual function, and perineal sensation. That’s why the statement placing the conus at around L1 and affecting S2–S5 is the best choice. The other options assign incorrect vertebral levels or sacral segments, which would imply different patterns of deficit.

The main idea is where the spinal cord ends and which nerve roots come from that region. The conus medullaris is the tapered end of the spinal cord and, in adults, it sits around the L1 vertebral level. From this area originate the lower sacral nerve roots that innervate pelvic organs and perineal structures. Because those sacral roots lie in the conus region, a lesion here most directly affects sacral function, particularly the S2–S5 segments, which govern bladder and bowel control, sexual function, and perineal sensation. That’s why the statement placing the conus at around L1 and affecting S2–S5 is the best choice. The other options assign incorrect vertebral levels or sacral segments, which would imply different patterns of deficit.