Anatomy

Cerebral Subcortex

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Cerebral Subcortex, Subcortical Region, Diencephalon

  • See Also
  1. Cerebrum
  2. Cerebellum
  3. Basal Ganglia
  4. Thalamus
  5. Hypothalamus
  6. Pituitary Gland
  7. Limbic System
  • Definitions
  1. Subcortical Region (Subcortex)
    1. Subcortical structures lie between the Cerebral Hemispheres and the Brainstem
    2. Includes Cerebellum, Basal Ganglia, Thalamus, Hypothalamus and Pituitary Gland
    3. Numerous interconnections to the Cerebral Hemispheres and Brain Stem
    4. Each subcortical formation has its own unique functionality, but function in combination with other regions
      1. Coordinate fine, smooth movement, memory and emotion, reward and pleasure
  • Anatomy
  1. Cerebellum
    1. Key function is coordinated movement
      1. Makes use of sensory input including proprioception to adjust movements
    2. Disorders of the Cerebellum (e.g. Posterior Circulation stroke)
      1. Tremor
      2. Nystagmus
      3. Ataxia (listing to one side while walking, difficulty with Rapid Alternating Movements)
  2. Basal Ganglia
    1. Collection of Neurons and their nucleii near the Thalamus that function to coordinate movement
    2. Interconnections to the Cerebral Hemispheres, Cerebellum, Thalamus and Brainstem
    3. Components
      1. Globus Pallidus
      2. Putamen
      3. Caudate
      4. Nucleus Accumbens
      5. Substantia Nigra
      6. Subthalamic Nucleus
    4. Functions
      1. Counter the excitatory signals from the Cerebellum to result in smooth movement
    5. Disorders
      1. Parkinsonism
      2. Chorea (sudden involuntary, uncoordinated jerky movements, e.g. Huntington's Chorea),
      3. Athetosis (slow, writhing movements)
      4. Hemiballismus (single extremity rapid, uncoordinated movement)
  3. Thalamus
    1. Functions as a central hub for incoming sensory signals relayed to the cerebral cortex
    2. Motor interconnections between the Cerebellum, cerebral cortex and target peripheral Neurons
    3. Thalamus functionality is divided among its 9 thalamic nucleii
  4. Hypothalamus and Pituitary Gland
    1. Hypothalamus innervates the posterior pituitary
      1. Pituitary releases Vasopressin and Oxytocin.
    2. Hypothalamus also generates releasing Hormones (e.g. Corticotropin)
      1. Corticotropin releasing Hormone acts on the anterior pituitary to release ACTH
        1. ACTH stimulates Cortisol secretion from the Adrenal Gland
      2. Thyrotropin-Releasing Hormone acts on anterior pituitary to release TSH
        1. TSH stimulates Thyroxine (T4, T3) secretion from the Thyroid
  5. Limbic System
    1. Complex interconnected neural pathways in the Diencephalon and brainsterm related to emotion and motivation
    2. Integrates visceral, olfacory and somatic inputs
    3. Structures include Hippocampus, Amygdala, Hypothalamus, Septal Nuclei, Thalamic anterior nuclear group