Cerebellum

 Cerebellum

Cerebellum is situated behind the pons and immediately below the posterior portion of cerebrum cerebrum occupying the posterior cranial fossa. 

It has two hemispheres called cerebellar hemisphere, separated by narrow median strip called vermis.

Grey mater forms the surface of cerebellum and white mater lies deeply, composed of nerve fibers.

Deep fissures subdivide each hemisphere into-

Anterior lobe

Posterior lobe

Flocculonodular lobes

Cerebellar Cortex covering the cerebellum surface of grey mater.

Cerebellar peduncles

The three paired fiber tracts. The cerebellar peduncles connect cerebellum to brain stem.

Superior cerebellar peduncles

Middle cerebellar peduncles

Inferior cerebellar peduncles

1. Superior cerebellar peduncles

Connect cerebellum and midbrain, contain mostly efferent fibers.

2. Middle cerebellar peduncles

Connect cerebellum and pons. These are largest peduncles. Contains afferent fibers.

3. Inferior cerebellar peduncles; smallest peduncles

Connect medulla with spinal cord and cerebellum contain both afferent and efferent fibers.

Inferior cerebellar peduncles convey sensory information to cerebellum from muscle proprioceptoes (joints) throughout body concerned with equilibrium and balance.

Middle cerebellar peduncles carry one way communication from pons to cerebellum, plan voluntary motor activities initiated by motor cortex.

After integrating and analyzing information from inferior and middle peduncles cerebellum send impulses through superior peduncles to mid brain. In response, motor impulses are transmitted down through pons, medulla oblongata and spinal cord to stimulate or inhibit skeletal muscles cause movements of body parts into desired position.

Function of cerebellum

Main role is to regulate balance, timing and position of body movement and body position and coordinates voluntary muscular movements.

Cerebellum controls and coordinates movements of various groups of muscle ensuring smooth, even, precise action.

It coordinates activates associated with maintenance of posture, balance and equilibrium maintain stable body position.

Cerebellum also have role in speech, movement of eye's, learning and language processing.

Damage to cerebellum result clumsy, uncoordinated muscular movement, inability to carry smooth, steady movement.

Monitors sensory input from organs.