Nervous System General functions: Sensory – receptors Integration & stores information as memory Response – motor – effectors

Classification Central Nervous System – brain & spinal cord Peripheral Nervous System – Afferent Somatic Visceral – Efferent Somatic Visceral = Autonomic Nervous System

Classification Autonomic Nervous System – Sympathetic Nervous System for fight or flight response – Parasympathetic Nervous System for rest and relaxation response

Key Points Classify the Autonomic Nervous System CNS or PNS Afferent or Efferent Sensory or Motor Somatic or Visceral

Neuron = Nerve Cell Cell body – Ganglion – Nucleus Cytoplasmic processes – Axon = Fiber Fiber tracts in CNS Nerve in PNS Sensory, Motor, Mixed – Dendrite

Synapse Junction between adjacent neurons [Telodendria – ends of axon] Neurotransmitters – chemicals bridging the synapse

Neuroglia = Nerve glue Supportive cells to neurons Ependymal cells – line the neurocoel and provide nutrients

Neuroglial Cells Oligodendroglia – produce myelin in CNS which is white and speeds up nerve impulse transmission

Neuroglial Cells Astrocytes – Maintain blood brain barrier

Key Points Parkinson’s Disease in humans is known to be caused by a decrease in dopamine (neurotransmitter) in the brain. Why not just inject patients with IV dopamine?

Neuroglial Cells Microglia – function as phagocytes

Key Points What is a phagocyte?

Neuroglial Cells Schwann Cells – Produce myelin in PNS

Key Points What is meant by white matter? What is meant by gray matter?

Development of Nervous System Neurulation Neural tube – Germinal layer – medial, with mitosis – Mantle layer – gray, cell bodies of neurons – Marginal layer – white – cytoplasmic processes without nuclei

Development of Nervous System Neuroblasts form neurons Spongioblasts form neuroglia Alar plate is dorsal gray matter (nuclei) Basal plate is ventral gray matter