Vestibulocerebellum, Spinocerebellum and Pontocerebellum

00:00 Now, we’ll explore the functions as well as input/outputs of each one of these functional divisions.

00:08 We’ll begin with the vestibulocerebellum. Functions: first, this functional division will maintain our posture.

00:21 as well as modulate or control our vestibular reflexes. The input is going to be via the vestibular nerve.

00:33 So the vestibular apparatus is activated. This stimulates the vestibular nerve. Then, its input is to the fastigial nucleus of the cerebellum. Output then from the fastigial nucleus is going to be via the cerebellovestibular tract. This will then connect to the vestibular nucleus. Then as a result, the vestibulospinal tract is activated. So you have control then of the muscles that are going to help maintain your posture. So, this then will activate the lower motor neurons at the appropriate levels of the spinal cord. The spinocerebellum, we’ll look at its functions as well as input/outputs.

01:36 Functions of the spinocerebellum include integrating sensory input with motor output.

01:45 This will help with the adaptive coordination of muscle movement. The input, as the name implies, is via the spinocerebellar tract. From the spinal cord to the interposed nucleus, that cerebellar nucleus, you’ll be utilizing this ascending tract, the spinocerebellar tract. Synapses will take place in the interposed nucleus. Then as a result, we’ll have outputs to the reticular formation shown in the green box as well as the red nucleus. Then descending spinal cord pathways from these two structures will be activated.

02:36 Those would be the reticulospinal and rubrospinal tracts. That will stimulate lower motor neurons at the appropriate levels of the spinal cord to coordinate muscle movement. The third and final functional division is the pontocerebellum. Its functions as well as input/outputs: for functions, we have timing and planning of movements. This is the area of the cerebellum that’s involved in cognition.

03:18 The input is going to be from the pontine nuclei to the dentate nucleus. This will utilize the pontocerebellar tract.

03:31 Here we see output to the thalamic nuclei specifically the ventral anterior and ventral lateral thalamic nuclei.

03:41 From here, signals will be transmitted to the motor cortex. Upper motor neurons will be activated, stimulated.

03:50 Then, once those are stimulated, the axons from the upper motor neurons will travel down the corticospinal tract within the spinal cord to then excite lower motor neurons at the appropriate spinal levels.