Cerebellum Anatomy and Function

Patients with cerebellar lesions struggle to time movements precisely, exhibiting inconsistent release points when performing tasks like throwing a ball, or finger-tapping.

A region within the cerebellum that governs the timing of muscle contractions during motor activities.

A fast-conducting pathway in the motor system, crucial for rapid recovery from posture deviations and fine-finger movements.

Originates in the motor cortex regions (M1, SMA, PMA) and parietal lobe.

A descending motor pathway that controls face and eye movements, originating 'above the pyramids' (in the brainstem).

The corticobulbar tract has different functionalities for the upper and lower parts of the face, impacting facial muscle control in a different way for each area

An injury to the motor neuron pathway above the brainstem level, affecting the ability to activate specific muscles.

Damage to the motor neuron pathway below the level of the brainstem; the muscles are unable to respond, even with a correct/ working brain signal.

A major descending motor pathway that originates in the motor cortex, crosses over to the opposite side of the spinal cord, and controls fine motor functions, primarily those of the limbs.

A descending motor pathway that innervates axial muscles (torso, neck) and facilitates coordinated movements, using indirect pathways through the spinal cord.

A neuron in the brain or brainstem that directly or indirectly controls the lower motor neurons in the spinal cord, leading to muscle contraction.

A neuron in the spinal cord that directly innervates muscle fibers resulting in muscle contraction.

Motor units (MUs) are classified as either fast or slow, based on their speed of contraction and fatigue resistance.

The speed at which signals travel along a neuron's axon. It's influenced by the axon's diameter and myelination.

As we get older, we lose muscle mass and motor units are lost gradually, even more rapidly after 60, impacting movement and strength.

Falls are a serious public health issue, impacting older adults, often due to improper weight shifting.

The cerebellum plays a crucial role in coordinating and refining movement, especially in terms of timing and accuracy. It receives sensory information and helps adjust ongoing actions for smooth and precise execution.

The cerebellum is composed of two hemispheres connected by a midline structure called the vermis. It contains a large amount of neurons, densely packed within its folded outer layer, the cerebellar cortex.

The cerebellum is divided into three lobes: anterior, posterior, and flocculonodular. These lobes are primarily anatomical divisions, but they contribute to different functions: anterior and posterior lobes are involved in body and limb movement, while the flocculonodular lobe helps with balance and eye movements.

Cerebellar atrophy refers to the shrinking of the cerebellum, often due to neurodegenerative diseases. This can lead to problems with movement coordination, balance, and timing.

The cerebellum is critical for motor skill learning. As we practice new movements, the cerebellum helps refine and strengthen the neural connections responsible for executing those movements.

These terms describe movement errors related to distance: Hypometria is an undershoot, where a movement falls short of the intended target, while hypermetria is an overshoot, where the movement extends beyond the target.

People with cerebellar lesions often show impaired motor learning. They may have difficulty acquiring new motor skills or show slow progress in learning tasks, even if they can perform the task on a single attempt.

This task is commonly used to assess motor learning. Participants trace a target drawing while looking at a mirror image, requiring them to adapt their movements to the reversed visual input.