Damage to which tract produces loss of conscious proprioception (vibration and joint position sense) in the ipsilateral lower limb?
- A Anterior spinocerebellar tract
- B Fasciculus gracilis ✓
- C Posterior spinocerebellar tract
- D Lateral spinothalamic tract
Correct answer: B. Fasciculus gracilis
Explanation
The fasciculus gracilis (medial part of the posterior funiculus) conveys conscious proprioception, vibration sense, discriminative touch, and two-point discrimination from the ipsilateral lower limb. Its first-order neurons ascend ipsilaterally to synapse in the nucleus gracilis of the medulla; second-order fibers then cross as internal arcuate fibers to form the medial lemniscus. The spinocerebellar tracts carry unconscious proprioception. The lateral spinothalamic tract carries pain and temperature.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.