Nervous System

• What are the major divisions of the nervous system?

  Central and Peripheral Nervous Systems

  
• What are the structural differences between grey matter and white matter?

  Grey matter has cell bodies; white matter has axons
• What are the parts of a multipolar neuron in order of polarity?

  Dendrites, cell body, axon
• What are the types of glial cells and their functions?

  • Astroglia: Supply nutrients, maintain electrical potential
  • Ependymal cells: Line cavities, circulate cerebrospinal fluid
  • Microglia: Phagocytose debris, form scars
  • Oligodendrocytes: Myelinate CNS axons
  • Schwann Cells: Myelinate PNS axons
  • Satellite Cells: Cushion and support neurons
• What are the major functions of the nervous system?

  Sensation, integration, and response

  
• What establishes the resting membrane potential?

  Distribution of sodium and potassium ions
• What changes occur to the membrane during an action potential?

  Depolarization and repolarization of the membrane

  
• What are the differences between types of graded potentials?

  Graded potentials vary in magnitude and duration
• What are the functions and actions of the nervous system?

  1. Maintains homeostasis
  2. Coordinates involuntary and voluntary responses
  3. Integrates sensory information
• What is the first action of the nervous system when receiving stimuli?

  Receive a stimuli through sensory receptors
• How does the nervous system decide about stimuli?

  It processes and interprets sensory information

  
• What is the response of the nervous system to stimuli?

  Generates motor output activating muscles or glands

  
• In the driving example, what does seeing a red light represent?

  Sensory input
• What are the components of the central nervous system (CNS)?

  • Brain
  • Spinal cord
• What are the components of the peripheral nervous system (PNS)?

  • Cranial nerves
  • Spinal nerves
• What is the role of the CNS?

  Integrates and commands sensory data and motor commands

  
• What does the PNS consist of?

  Everything outside of the CNS
• What do spinal nerves do?

  Carry impulses to and from the spinal cord
• What do cranial nerves do?

  Carry impulses to and from the brain
• What is a reflex arc?

  • Rapid, predictable, involuntary response
  • Follows the same route every time
  • Cannot be stopped once initiated
• What are the five elements of a reflex arc?

  1. Sensory receptor
  2. Sensory neuron
  3. Integration center (CNS)
  4. Motor neuron
  5. Effector
• What is the difference between somatic and autonomic reflexes?

  Somatic reflexes stimulate skeletal muscle; autonomic reflexes stimulate smooth muscle
• What are the two main components of nervous tissue?

  • Neurons
  • Neuroglia
• What is the function of neurons?

  Transmit nerve impulses

  
• What is the function of neuroglia?

  Support and protect neurons
• What are the key components of a neuron?

  1. Cell body (soma)
  2. Dendrites
  3. Axon

  
• What is the role of the cell body in a neuron?

  It is the nucleus and metabolic center
• What do dendrites do?

  Convey incoming messages towards the cell body
• What does the axon do?

  Generates and conducts nerve impulses away from the cell body
• What is the resting membrane potential (RMP) of a neuron?

  • 70 mV
• What is the chief extracellular ion in a resting neuron?

  Sodium (Na+)
• What is the chief intracellular ion in a resting neuron?

  Potassium (K+)
• What maintains the resting membrane potential?

  Na+/K+ pump
• What happens when a neuron is excited by a sensory stimulus?

  It depolarizes and sodium channels open
• What is a graded potential?

  Local change in membrane potential

  
• What are the types of sensory stimuli?

  1. Mechanical: touch, pressure
  2. Thermal: heat, cold
  3. Chemical: histamine, oxygen levels
  4. Environmental: light, sound
• What triggers an action potential?

  Strong enough stimulus and influx of Na+
• How does the action potential propagate along the axon?

  Membrane permeability changes rapidly in adjacent areas

  
• How does myelination affect nerve impulse propagation?

  It allows impulses to jump from node to node
• What is the nature of the action potential response?

  All or nothing response