At the level of the pons, the somatotopic arrangement of the medial lemniscus places fibres carrying sensation from which body region most laterally?
- A Lower limb ✓
- B Sacral region
- C Upper limb
- D Trunk
Correct answer: A. Lower limb
Explanation
In the caudal medulla the medial lemniscus is a flattened band with sacral segments ventral and cervical segments dorsal. As it ascends into the pons it rotates, so that by pontine levels the lower limb fibres come to lie laterally and the upper limb and trunk fibres medially. This rotation explains why a lateral pontine lesion preferentially affects contralateral leg modalities carried in the medial lemniscus.
Reference: Gray's Anatomy, 42nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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