cerebellar peduncle

Examples of cerebellar peduncle in the following topics:

• Somatic Sensory Pathways to the Cerebellum

  • The ventral spinocerebellar tract then enters the cerebellum via the superior cerebellar peduncle (connects the cerebellum to the midbrain).
  • The fibers of the ventral spinocerebellar tract then eventually enter the cerebellum via the superior cerebellar peduncle.
  • This is one of the few afferent tracts through the superior cerebellar peduncle.
  • These axons ascend to the pons where they join the superior cerebellar peduncle to enter the cerebellum.
  • Once in the deep, white matter of the cerebellum, the axons recross the midline, give off collaterals to the globose and emboliform nuclei (deep cerebellar nuclei), and terminate in the cortex of the anterior lobe and vermis of the posterior lobe.

• Pons

  • Posteriorly, it consists mainly of two pairs of thick stalks called cerebellar peduncles.

• Vagus (X) Nerve

  • Upon leaving the medulla between the medullary pyramid and the inferior cerebellar peduncle, it extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein below the head, to the neck, chest and abdomen, where it contributes to the innervation of the viscera.

• Medulla Oblongata

  • The fossa is bounded on either side by the inferior cerebellar peduncle, which connects the medulla to the cerebellum.

• Functions of the Cerebellum

  • Animals and humans with cerebellar dysfunction show problems with motor control.
  • Modularity: The cerebellar system is functionally divided into thousands of independent modules.
  • A module consists of a small cluster of neurons in the inferior olivary nucleus, a set of long narrow strips of Purkinje cells in the cerebellar cortex (microzones), and a small cluster of neurons in one of the deep cerebellar nuclei.
  • One of the most extensively studied cerebellar learning tasks is the eyeblink conditioning paradigm.
  • Experiments showed that lesions localized either to a specific part of the interpositus nucleus (one of the deep cerebellar nuclei), or to a few specific points in the cerebellar cortex, abolished learning of a correctly timed blink response.

• Functions of the Cerebellum in Integrating Movements

  • The cerebellar system is functionally divided into more or less independent modules, that probably number in the hundreds to thousands.
  • A module (a multizonal microcompartment in the terminology of Apps and Garwicz) consists of a small cluster of neurons in the inferior olivary nucleus, a set of long narrow strips of Purkinje cells in the cerebellar cortex (microzones), and a small cluster of neurons in one of the deep cerebellar nuclei.
  • This arrangement gives tremendous flexibility for fine-tuning the relationships between the cerebellar inputs and outputs.
  • Transverse section of a cerebellar folium, showing its principal cell types and connections.
  • These zones and microzones help explain the modular nature of the cerebellar function.

• Modulation of Movement by the Cerebellum

  • Animals and humans with cerebellar dysfunction show, above all, problems with motor control.
  • A standard test of cerebellar function is to reach with the tip of the finger for a target at arm's length.
  • The comparative simplicity and regularity of the cerebellar anatomy led to an early hope that it might imply a similar simplicity of computational function.
  • Modularity: The cerebellar system is functionally divided into independent modules.
  • This arrangement gives tremendous flexibility for fine-tuning the relationship between the cerebellar inputs and outputs.

• Ataxia

  • Cerebellar ataxia is ataxia that is due to dysfunction of the cerebellum .
  • People with cerebellar ataxia may have trouble regulating the force, range, direction, velocity, and rhythm of muscle contractions.
  • As cerebellar ataxia becomes severe, great assistance and effort are needed in order to stand and walk.
  • Ethanol is capable of causing reversible cerebellar and vestibular ataxia.
  • Vitamin B12 deficiency may cause, among several neurological abnormalities, overlapping cerebellar and sensory ataxia.

• Midbrain

  • Anatomically, it comprises the tectum (or corpora quadrigemina), tegmentum, ventricular mesocoelia (or "iter"), and the cerebral peduncles, as well as several nuclei and fasciculi.
  • The cerebral peduncles are located on either side of the midbrain and are its most anterior part, acting as the connectors between the rest of the midbrain and the thalamic nuclei.
  • The cerebral peduncles assist in motor movement refinement, motor skill learning, and converting proprioceptive information into balance and posture maintenance.

• Parts of the Cerebellum

  • These parallel grooves conceal the fact that the cerebellum is actually a continuous thin layer of tissue (the cerebellar cortex), tightly folded in the style of an accordion.
  • This complex neural network gives rise to a massive signal-processing capability, but almost all of its output is directed to a set of small deep cerebellar nuclei lying in the interior of the cerebellum.
  • It sends fibers to deep cerebellar nuclei that in turn project to both the cerebral cortex and the brain stem, thus providing modulation of descending motor systems.
  • Transverse section of a cerebellar folium, showing principal cell types and connections.