netter22

NEUROPHYSIOLOGY

Cerebellum: Afferent Pathways

Cortical input

uperior cerebellar peduncłe

Midrłle cerebellar peduncłe

Cortical input

Spinał bortter cells

Lumbar part

ot spinał cord

Functional Subdivisions of Cerebelluni

Hemisphere Ve

ungula /    /

Flocculus / Nodule —'

«. JlI^,uUrr

i_m)|Pyram'd-

Ventral spino

Leg /one Arm zonę Face zonę

2nd spinał

prnjpc tmn

igranie

Spinał input Interior

Upper part ot medulla oblongata

Vestibular and ganglion

Spinał input Cervical parł of spinał cord    |

Motor intcrneuron Rost rai

spinocerebellar traci

To nodule and tlocculus Interior cefebellar peduncłe

Cuncocerebellar traci

Gracile nurteus Matn cuncatc nudeus (relay tor cutaneous intormation)

External runeate nucleus {relay ter proprioceptive information)

From skin (touch and pressure)

musde (spindlcs and Golgi tcndon organs) From skin and tleep tissues (pain and Golgi tcndon organs) skin (toucłi and pressure) and from muscłe ispindles and Golgi tcndon organs)

Dorsal spinocerebellar traci

Archi-ccrcbellum (vestibulo-cercbcllum)

Paleocerebellum (spinocerebellum)

Antcrior lobe

Primary

Ncoccrcbcllun

(pontoccrebcllum) l Hemisphere

"unfoldine"

above diagram

Figurę 2.21 Cerebeuar Aeeeremt Pathways

The ccrcbellum plays an important role in coordinating n>ovcmenL It rcceivcs sensory intormation and then influenr.es descending motor pathways to produce fine, smooth. and coordinated motion. Ihc ccrcbellum is divided mto three generał areas: archicerebełlum latso called vestibulocerebeBum) paleocerebellum (also called spinocerebefium) and ihc neocerel>ellum talso called the cerebrocerebdlum). The ar< hi< ereł>ellum is primarily involved in controlling posturę and bal-ance, as well as the movpment ot the head and eyes. It receives affer-ent signals from the vcstibular apparatus and then sends cnercnt tibers to the appropriate descending motor pathways. The paleocerebellum pnmańly Controls movement of the proximal portions of the limbs. It ret eives sensory information on limb posilion and muscłe tonę and then modities and coordinates these rrtovements through efferent pathways to the appropriate descending motor pathways. The neocerebel lum is the latgesl portion ol the c erebelluni, and it coordinates the movement oi the distal portions ot the limbs. It receives input trom the cerebral corte* and thus helps in the planning of motor activity (e.g. seeing a pencil and then planning and execuling the movement of the arm and hand to pick it up).

32