Week 8 Neuroanatomy

Functions of cerebellum

Functions of cerebellum

Voluntary smooth coordinated movement

Anterior lobe

Paleocerebellum

paleocerebellum

spinal cerebellum

posterior lobe

neocerebellum

neocerebellum

cerebral cerebellum

flocculonodular lobe

archicerebellum

archicerebellum

vestibular lobe

Superior cerebellar peduncle

brachium conjunctivum, connects the cerebellum to the midbrain. Although it contains a limited number of input fibers, its most abundant and most important components are output fibers.

middle cerebellar peduncle

brachium pontis, is the largest peduncle and connects the basilar part of the pons to the cerebellum. Its fibers are entirely input.

inferior cerebellar peduncle

arches dorsally from the dorsolateral surface of the medulla. Its composition is chiefly input fibers, although it does contain some output fibers. It consists of a large lateral part, the restiform body, and a small medial part, the juxtarestiform body.

flocculonodular lobe

flocculus

nodulus

anterior lobe

posterior lobe

vermis

folium

ridges and Gyri in the cerebellum

primary fissure

posterolateral fissure

fastigial nuclei

Interposed nuclei

Emboliform and globus nuclei

dentate nuclei

Functions of posterior lobe

Upper extremities, precise coordinated movement

posterior lobe syndrome

intentional tremor, perpendicular movement to intended, dysmetria

inputs to posterior lobe

(Corticopontine fibers) Association cortex→ internal capsule/ crus cerebri → Pontine nuclei

(Pontocerebellar fibers) Pontine nuclei→ transverse pontocerebellar fibers/middle cerebellar peduncle→ Dentate nucleus

outputs to posterior lobe

(Dentatothalamic fibers) Dentate nucleus→ Superior cerebellar peduncle and decussation→ Thalamus

(Thalamocortical fibers) Thalamus→ internal capsule→ Motor cortex

Functions of anterior lobe

Axial and lower extremity movements (gait and station)

anterior lobe syndrome

Loss of coordination in lower limbs (Heel-shin test)

inputs to the anterior lobe from the lower limb

(primary sensory neuron) Dorsal root ganglia (L and S)→ gracile tract→ dorsal thoracic nucleus of Clarke

(Secondary neuron) Dorsal thoracic nucleus of clarke→ Dorsal spinocerebellar tract/ inferior cerebellar peduncle→ Fastigial nucleus/interposed nuclei

inputs to anterior lobe from upper limb

(Primary sensory neuron) Dorsal root ganglion (C)→ cuneate tract→ accessory cuneate nucleus

(Secondary neuron) Accessory cuneate nucleus→ inferior cerebellar peduncle→ Fastigial nucleus/ interposed nucleus

outputs from the anterior lobe

(output 1) Fastigial nucleus→ Inferior cerebellar peduncle→ vestibular nuclei

(output 2) interposed nuclei→ Superior cerebellar peduncle and decussation→ red nucleus

functions of flocculonodular lobe

Eye, Neck, and trunk movement

flocculondodular lobe syndrome

Trunkal Ataxia

inputs to flocculonodular lobe

(primary sensory neuron) Vestibular apparatus of the inner ear→ CN VIII→ Vestibular nuclei

(secondary neuron) Vestibular nuclei→ Inferior cerebellar peduncle→ Fastigial nucleus

outputs from the flocculondular lobe

(fastigiobulbar projection) Fastigial nucleus→Inferior cerebellar peduncle→ Vestibular nuclei

(vestibulospinal and vestibuloocular projections) Vestibular nuclei→ Medial longitudinal fasciculus→ CN III, IV, VI nuclei and medial motor nucleus in spinal cord.