Basal ganglia

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The basal ganglia is a group of subcortical nuclei which are derived from the telencephalon, diencephalon, and mesencephalon. It coordinates initiation, termination, tone, and precision of movements, and – together with the limbic system – coordinates motivational movements. The basal ganglia participates in high-level movement including the planning of movement synergies, movements related to posture (e.g., swinging the arms while walking), and skilled volition (e.g., eye movements). Lesions of the basal ganglia could result in Parkinson's disease or Huntington's chorea

Components

Corpus striatum

Basics

  • telencephalic origin
  • the primary group of nuclei in the basal ganglia
  • The Corpus striatum's components have reciprocal projections with the subthalamic nuclei and substantia nigra

Nuclei

  • Striatum
    • the term is derived from neostriatum
    • Has two distinct groups of nuclei:
      1. Putmanen (Pod)
      2. Caudate nucleus (Tail)
        • head
          • connected to the rostral portion of the putamen by bands of axonal fibers
          • situated anterior to the thalamus
        • body
          • curves posteriorly and medially
          • situated superior to the thalamus
        • tail
          • curves anteriorly and inferiorly
          • situated in the medial portion of the temporal lobe
          • ends as the amygdala, a nucleic group belonging to the limbic system
  • Pallidum
    • The term is derived from paleostriatum, which is phylogenetically older than neostriatum
    • Developed into globus pallidus (old/pale globe)
    • In the adult form, it is composed of two layers of nuclei
      1. external (GPE)
      2. internal (GPI)
  • Lentiform nucleus
    • The putamen and globus pallidus join to form the lentiform nucleus
    • Lies deep to the insula cortex
    • putamen is situated laterally, GPE in the middle, and GPI medially
    • Situated lateral to the thalamus

Subthalamic nuclei

  • diencephalic

Substantia nigra

  • mesencephalic

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