cerebellum Flashcards
Functions of the cerebellum
Coordination (agonist-antagonist, whole limb).
Control of movement initiation.
Balance.
Oculomotor control.
Learning of movement.
Provide parametric computations for cognition.
3 subdivisions based on
3 subdivisions based on source of input
describe the Cerebrocerebellum
- Most lateral part of cerebellar hemisphere.
- Receives indirect input from many areas of the cerebral cortex.
- Planning, coordination and execution of complex spatial and temporal sequences of movement.
- Cognitive functions (timing, attention, sensation monitoring).
describe the Spinocerebellum
- Vermis (Median) and paramedian zones.
- Receives direct input from the spinal cord.
- Paramedian zones are involved with movement of distal muscles.
- Vermis is involved with movement of the proximal muscles and eyes
- Control of ongoing movements
describe the Vestibulocerebellum
- Phylogenetically oldest part of the cerebellum
- caudal-inferior lobes of the cerebellum and includes the flocculus and nodulus
- Receives input from vestibular nuclei in the brainstem
- Vestibulo-ocular reflex
- regulation of movements that maintain posture, balance, equilibrium.
The connections between the cerebellum and other parts of the nervous system are made by
by three large pathways called cerebellar peduncles.
Middle – afferent pathway with 20 million axons each!!
Inferior – multiple afferent and efferent pathways
Superior – mainly an efferent pathway
Middle cerebellar peduncle
- Afferent pathway from pontine nuclei.
- Pontocerebellar fibers cross the midline and enter the contralateral cerebellum via the middle cerebellar peduncle.
Somatotopic maps of the body surface in the spinocerebellum
- The vestibular and spinal inputs remain ipsilateral as they pass through the inferior cerebellar peduncle and enter the cerebellum.
- The cerebellum is concerned with ipsilateral representations of the body and external space.
what enters through the Inferior cerebellar peduncle and where they terminate
- Vestibular axons (CNVIII) and axons of vestibular nuclei in the pons and medulla enter via the inferior peduncle to the vestibulocerebellum.
- Dorsal nucleus of Clarke in the spinal cord and the external cuneate nucleus in the caudal medulla send their axons to the spinocerebellum.
- Proprioceptive signals from the face are relayed via the mesencephalic trigeminal nucleus to the spinocerebellum.
Inferior cerebellar peduncle:
The vestibular, spinal, and trigeminal inputs provide the cerebellum with
information from the labyrinth in the ear, muscle spindles, and other mechanoreceptors that monitor the position and motion of the body.
**Visual and auditory signals are relayed via brainstem nuclei to the cerebellum; they provide the cerebellum with additional sensory signals that supplement the proprioceptive information regarding body position and motion
Inferior cerebellar peduncle:
The entire cerebellum receives modulatory inputs from
the inferior olive nucleus in the medulla oblongata. These inputs participate in the learning and memory functions served by cerebellar circuitry.
The inferior olive receives input from ?
The inferior olive receives input from a wide variety of structures, including the cerebral cortex (via a relay in the parvocellular division of the red nucleus), the reticular formation, and the spinal cord.
The so-called olivo-cerebellar axons exit from? and where does it enters? explain
The so-called olivo-cerebellar axons exit medially from the inferior olive, cross the midline, and enter the cerebellum on the opposite side via the inferior cerebellar peduncle
Superior cerebellar peduncle mainly
an efferent pathway
Superior cerebellar peduncle goes from the and to the?
from the deep cerebellar nuclei to the motor nuclei of the thalamus and superior colliculus
