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Cerebellum: Efferent Pathways

NEUROPHYSIOLOGY

Exritatory

endmts

Inhibitory endings of Purkinjc cells

cerebral

cortex

‘ Interna! capsule

Mesencephalic reticular formatiom

Red nudeus.,

Fastigial nudeus

Clobose nuclei

Cerebral pedunde

Decussation of superior cerebellar pcduncles

Descending fibers from superior cerebellar peduncles

- Hook bundle of Russell

Emboliform nudeus

Dentate nudeus

Cerebellar

Section

A-B

viewed

from

below

Vestibular nudei-

Inferior cerebellar peduncle

Inferior olive Lateral reticular nudeus

Medulla oblongata Pontomedullary reticular formation

Planes of section: red arrows indicate direction

Section

B-C

viewed

from

above

Figurę 2.22 Cerebellar Efferent Pathways_

The cerebellum plays an important role in coordinating movement. It influences descending motor pathways to produce fine, smooth, and coordinated motion. The archicerebellum is primarily involved in controlling posturę and balance and movement of the head and eyes. It sends efferent fibers to the appropriate descending motor pathways. The paleocerebcllum primarily Controls movement of the proximal portions of the limbs. It modifies and coordinates these movements through efferent pathways to the appropriate descending motor pathways. The neocerebellum coordinates the movement of the distal portions of the limbs. It helps in the planning of motor activity (e.g., seeing a pencil and then planning and executing the movement of the arm and hand to pick ił up).