2. NERVOUS SYSTEM

• What are the two divisions of the nervous system?

  Central and peripheral nervous systems
• What is the primary function of neurons?

  Computation and communication in the nervous system
• What are the two types of cells in the nervous system?

  Neurons and neuroglia
• How do neuroglia support neurons?

  By maintaining homeostasis and protection
• How does the shape of a neuron relate to its function?

  Shape is determined by function and location
• What are the three parts of a neuron?

  Cell body, axon, dendrites
• What is the role of the cell body in a neuron?

  Integrates signals and metabolism
• What is the function of dendrites?

  Receive information and transmit it
• What does the axon do?

  Transmits information away from the cell body
• What is the term for the membrane surrounding the axon?

  Axolemma
• What type of neurons are most common in the brain and spinal cord?

  Multipolar neurons
• Where are bipolar neurons typically found?

  In the retina, ear, and olfactory area
• What are unipolar neurons associated with?

  Sensory functions
• What is the function of glial cells?

  Support and protect neurons
• What do oligodendrocytes do?

  Form myelin sheath around axons
• What is the role of microglia?

  Protect CNS cells from diseases
• What do ependymal cells line?

  Central cavities of the brain and spinal cord
• What is the function of astrocytes?

  Maintain chemical environment for neurons
• What is myelination?

  Wrapping neurons in a lipid sheath
• What are the functions of myelination?

  Protection, insulation, and speed increase
• What are the two types of neuroglia that produce myelin sheath?

  Schwann cells and oligodendrocytes
• What is a synapse?

  Functional junction between neurons
• What are the two types of signal transmission at synapses?

  Electrical and chemical
• How do electrical synapses communicate?

  Directly through gap junctions
• What happens at a chemical synapse?

  Electrical signal converts to chemical signal
• What is an excitatory postsynaptic potential (EPSP)?

  Depolarization of the postsynaptic membrane
• What causes hyperpolarization in inhibitory transmission?

  Opening of chloride or potassium channels
• What is the role of the neuromuscular junction?

  Connects motor neurons to muscle fibers
• What is the typical structure of a motor neuron at the muscle layer?

  Divides into several branches
• What disease is mentioned in the study material related to the nervous system?

  Myasthenia gravis
• What is the function of Schwann cells?


  Produce myelin sheath in PNS
• What is the difference between action potential and resting potential?

  Action potential is a nerve impulse; resting potential is inactive state
• Why are neurotransmitters important in synaptic transmission?

  They convert electrical signals to chemical signals
• What connects motor neurons to muscle fibers?

  Motor end-plates or neuromuscular junction
• How many neuromuscular junctions are typically found per skeletal muscle fiber?

  Usually one neuromuscular junction
• What type of process is the transmission of neural messages along a neuron?

  Electrochemical process
• What is the charge difference across a neuron's plasma membrane?

  Positive outside, negative inside
• What ions contribute to the resting potential of a neuron?

  Sodium and potassium ions
• What is the typical resting potential value in millivolts?

  • 70 millivolts
• What maintains the charge difference across the neuron's membrane?

  Sodium-potassium pump