24
🎯 Main Points

Chapter 24

PSYP610 - Neurological Bases of Behavior

🔑 Key Definitions

Unipolar Neuron: Neuron with one process extending from cell body; typical of sensory neurons in PNS
Bipolar Neuron: Neuron with two processes (one dendrite, one axon); found in retina and olfactory system
Multipolar Neuron: Neuron with many dendrites and one axon; most common type in CNS
Blood-Brain Barrier: Selective barrier formed by tight junctions between capillary endothelial cells; protects brain from toxins

🧠 Glial Cell Types

  • Astrocytes: Star-shaped cells that provide structural support, regulate blood flow, maintain chemical environment
  • Oligodendrocytes: Form myelin sheaths around CNS axons; one oligodendrocyte myelinates multiple axons
  • Microglia: Immune cells of CNS; remove debris and pathogens through phagocytosis
  • Schwann Cells: Form myelin in PNS; one cell per axon segment (not mentioned as extensively but important for comparison)

📊 Meninges (Protective Layers)

  • Dura Mater: Tough outer layer ("hard mother"); thick protective covering
  • Arachnoid Mater: Middle web-like layer; contains CSF in subarachnoid space
  • Pia Mater: Thin inner layer ("soft mother"); adheres directly to brain surface

💧 Ventricular System & CSF

  • Lateral Ventricles: Two ventricles in cerebral hemispheres
  • Third Ventricle: Midline ventricle in diencephalon
  • Fourth Ventricle: Between pons and cerebellum
  • CSF Functions: Cushions brain, removes waste, maintains chemical stability

💡 Exam Tips

  • Remember neuron types: UNI-polar (1 process), BI-polar (2 processes), MULTI-polar (many dendrites)
  • Meninges order (outside to in): Dura → Arachnoid → Pia
  • Astrocytes = support/regulation, Oligodendrocytes = myelin (CNS), Microglia = immune
  • Blood-brain barrier protects but also blocks some medications
  • CSF circulates through all four ventricles
  • Know the difference: oligodendrocytes (CNS, multiple axons) vs Schwann cells (PNS, one segment)