VPB 121: Veterinary Physiology - II (2+1)

CEREBELLUM

• It is encased in cerebellar hemisphere and is located the back of the brain.
• Responsible for motor coordination by integrating sensory inputs from receptors located from muscles eyes and ears with motor orders of the fore brain.
• It maintains equilibrium and posture.
• Present in the anterior part of the brainstem, dorsal to the pons and medulla, and caudal to the cerebral cortex so called as little brain. It contains many neurons.
• It is present in all mammals. Jawless vertebrates lack cerebellum.
  It is concerned with proper positioning of the body in the space. It maintains subconscious coordination of the movement and coordinates fast phasic motor activity.
• Cerebellum is extensive in birds where they need to balance while flying.
• The anatomy of the cerebellum is as follow,
  • Made up of outer grey matter layer known as the CEREBELLAR CORTEX.
  • White matter of cerebellum is represented by stalks known as CEREBELLAR PEDUNCLE.

  

  • Three pairs of the cerebellar peduncle functions as sensory and motor fibers to and from cerebellum and through which it is attached to the brainstem.
    • Brachium conjunctivum-to thalamus and mesencephalon. It is the rostral cerebellar peduncle.
    • Brachium pontis-to pons. It is the middle cerebellar peduncle.
    • Restiform body-to medulla and spinal cord. It is the caudal cerebellar peduncle. 

  

  • Group of cerebellar nuclei known as subcortical nuclei is embedded in the cerebellar white matter, whose axons leave the cerebellum. They are dentate nucleus, globus emboliformis and fastigial nucleus.