Nervous system

• Central Nervous System (CNS)


  Where information is processed, contains the brain and spinal cord
• Peripheral Nervous System (PNS)


  Constructed of a network of sensory and motor nerves
• Somatic Nervous System (SNS)


  Used for voluntary actions, under conscious control
• Autonomic Nervous System (ANS)


  Controls internal organs and glands, involuntary system
• Branches of the ANS


  • Sympathetic
  • Parasympathetic
• Sympathetic branch


  Activated in stress/fight-or-flight response, increases bodily activity needed for survival
• Parasympathetic branch


  Activated in rest response, decreases bodily activity
• Homeostasis

  Balance between sympathetic and parasympathetic branches
• Fight-or-flight response


  1. Brain detects threat

  2. Hypothalamus triggers sympathetic branch

  3. Adrenal glands release adrenaline and noradrenaline

  4. Biological processes change to focus on survival
• James-Lange theory


  Physiological changes in the body cause emotions, not the other way around
• The James-Lange theory struggles to explain how the brain decides which emotion to feel</b>
• The Cannon-Bard theory suggests physical and emotional responses happen separately but at the same time
• Neuroscience research shows complex emotions are processed slowly across the brain, while simple emotions like fear travel directly to the amygdala