The dentate nucleus of the cerebellum is the largest and most lateral of the cerebellar nuclei. Efferent fibers from the dentate nucleus leave via which cerebellar peduncle to reach the contralateral red nucleus and thalamus?

• A Superior cerebellar peduncle (brachium conjunctivum), decussating in the midbrain tegmentum ✓
• B Middle cerebellar peduncle (brachium pontis)
• C Inferior cerebellar peduncle (restiform body)
• D Direct projection via the medial longitudinal fasciculus

Explanation

Cerebellar efferents from all deep nuclei (dentate, emboliform, globose, fastigial) exit via the superior cerebellar peduncle, which decussates in the caudal midbrain (decussation of the brachium conjunctivum). After decussation, fibers synapse in the contralateral red nucleus (rubrospinal coordination) and VL/VPLc thalamic nuclei (dentato-rubro-thalamic tract) before reaching the motor cortex. The middle cerebellar peduncle is predominantly an AFFERENT pathway (corticopontocerebellar). The inferior cerebellar peduncle carries both afferents (spinocerebellar, vestibulocerebellar) and some efferents (fastigiovestibular). The MLF is an oculomotor/vestibular tract, not a cerebellar efferent.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.