Cerebellum | Medical Science Optional Notes for UPSC PDF Download

Structure

• The cerebellum consists of two hemispheres separated by a midline structure known as the vermis.
• The most caudal part of the cerebellar hemispheres is identified as cerebellar tonsils.
• Three peduncles establish connections between the cerebellum and the brainstem.
• The cerebellum comprises:
  • Grey matter in the outer cortex, which receives afferent inputs from the cerebrum and spinal cord, transmitting them to the cerebellar nuclei.
  • White matter in the inner cortex, arranged in a branching tree-like pattern, housing the four deep cerebellar nuclei.

Location

• Positioned within the posterior cranial fossa above the foramen magnum.
• Situated inferior to the occipital and temporal lobes.
• Covered by the tentorium cerebelli (dura mater).
• Separated from the medulla and pons by the fourth ventricle.

Functions of cerebellum

• Coordinating motor movements
• Planning and regulating motor activities
• Controlling muscle tone

• Dysdiadochokinesia: A diminished capacity to execute swift, alternating movements.
• Prone-Supine Test: A test assessing dysdiadochokinesia.
• Dysmetria: Coordination deficiency resulting in undershooting or overshooting the intended position with the hand, arm, leg, or eye.
• Finger-Nose Test/Heel-Shin Test: Tests designed to evaluate dysmetria.

Cerebellum-Repeats

1. Explain the functions of the spinocerebellum. (2017)
2. Elaborate on the cerebellum's role in the regulation of posture and movement. Define cerebellar ataxia. (2016)
3. Outline the functional divisions of the cerebellum and the consequences of lesions in each division. (2009)
4. Provide a list of features associated with cerebellar lesions and discuss their physiological basis. (2006)