ORGANIZATIONAL PRINCIPLES OF THE BRAIN:

• Brain


  An assembly of interrelated neural systems that regulate their own and each other's activity in a dynamic, complex fashion largely through intercellular chemical neurotransmission
• Cerebral Cortex


  • The two cerebral hemispheres constitute the largest division of the brain
  • Cortical areas termed association areas process information from primary cortical sensory regions to produce higher cortical functions such as abstract thought, memory, and consciousness
  • The cerebral cortices also provide supervisory integration of the autonomic nervous system and integrate somatic and vegetative functions, including those of the cardiovascular and gastrointestinal systems
• Diencephalon


  • The thalamus lies in the center of the brain, beneath the cortex and basal ganglia and above the hypothalamus
  • The neurons of the thalamus are arranged into distinct clusters, or nuclei, which are either paired or midline structures
  • These nuclei act as relays between the incoming sensory pathways and the cortex, between the discrete regions of the thalamus and the hypothalamus, and between the basal ganglia and the association regions of the cerebral cortex
  • The hypothalamus is the principal integrating region for the entire autonomic nervous system and regulates body temperature, water balance, intermediary metabolism, blood pressure, sexual and circadian cycles, secretion of the adenohypophysis, sleep, and emotion