Hormones, The Brain, and Brain Scans

Hormones

• Chemical messengers produced by endocrine glands
• Released into the bloodstream, travel throughout the body
• Bind to specific receptor sites on target organs
• Examples:
  • Adrenaline: Fight-or-flight response. Increases heart rate, blood pressure, and respiration.
  • Melatonin: Regulates circadian rhythms and sleep-wake cycle. Associated with seasonal affective disorder.
  • Oxytocin: Social bonding, trust, and attachment. Involved in childbirth, breastfeeding, and tend-and-befriend stress response.
    • May reduce stress by inhibiting the amygdala and activating the parasympathetic nervous system.

The Brain

• Most complex creation in the known universe
• Neuroscientists adopt a materialist view of the mind - that everything mental is biological.
• Weighs approximately 3 pounds, uses approximately 20% of the body's energy

Brain Scans

• CAT: Cut - X-ray "cuts" to create a 3D image - structure, finds tumors
• MRI: Magnet - magnetic fields and radio waves to measure density - detailed image
• EEG: Electricity (Brain Waves) - measures "electrical waves" of brain activity. Sleep research
• PET: Party (Glucose Activity) - tracks glucose consumption
• fMRI: Film (Blood Flow) - detects blood flow changes