Nervous System

General functions:Sensory – receptorsIntegration & stores information as memoryResponse – 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 SystemCNS or PNSAfferent or EfferentSensory or MotorSomatic 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 neuronsEpendymal 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

NeurulationNeural 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 neuronsSpongioblasts form neurogliaAlar plate is dorsal gray matter (nuclei)Basal plate is ventral gray matter