Nervous System

Subdecks (2)

Cards (91)

  • The nervous system works in conjunction with what?
    endocrine system
  • Nervous System
    responds to both internal and external environment change and maintains homeostasis within the body
  • Glial Cell
    structural and nutritional support
  • Neurons
    conduct nerve impulses throughout the body. they are supported by the glial cells
  • Dendrites
    branches which accept nerve impulses form other neurons and carry them towards the cell body
  • Axon
    longer branches which carry nerve impulses away from the cell body
  • Myelin Sheath
    around the axon, speeds up the rate of impulse transmission
  • Schwann Cell
    produces the myelin
  • Nodes of Ranvier
    gaps between the Schwann cells
  • Axon Terminal
    end of the axon and passes the electrical signal to other neurons
  • Myelinated Neurons

    "white matter" which conducts nerve impulses, can regenerate after injury
  • Unmyelinated Neurons

    "grey matter" responsible for processing information, cannot regenerate after injury
  • Sensory Neurons (afferent)

    gather information from sensory receptors, transmit the impulses to the brain
  • Interneurons
    process and integrate sensory information from sensory neurons and relay information to motor neurons
  • Motor Neurons (efferent)

    transmit information from the brain to muscles(effectors)
  • Reflex Arc
    neural circuit that passes through interneurons in the spinal cord for immediate response
  • Summation
    sum of multiple neurons leads to greater stimulation
  • What are the four stages of a nerve impulse?
    polarized, depolarization, repolarization, and refractory period
  • Resting State/Polarized

    inside of neuron has a slight positive charge at rest and the outside has a slight negative charge. has a potential at -70mV
  • Does sodium ions go in or out?
    in
  • Does potassium ions go in or out?
    out
  • Depolarization
    an impulse causes the sodium gates to open and sodium rushes into the cell, causing a more positive charge and reverses the membrane potential to +40mV
  • Threshold
    any stimulus that does not reach a potential of -55mV will have no effect
  • Stimulus Strength
    if an increase of stimulus strength occurs, there will not be an increase of impulse strength. there will only be an increased frequency of nerve impulses
  • Repolarization
    once action potential is reached sodium gates close and the potassium gates open, K+ rushes out of the axon and restores the positive charge on the outside and goes back to the initial resting potential of -70mV
  • Hyperpolarization
    will become too negative (-70mV to -90mV) until the resting potential has been restored by the sodium-potassium pump. a second action potential cannot be conducted along the axon
  • Neurotransmitters
    help "carry" the electrical impulse from one neuron to another
  • Pre-Synaptic Membrane
    axon terminal
  • Post-Synaptic Membrane
    dendrites
  • First step of Synapse
    action potential reaches the axon terminal and the calcium gates open causing calcium ions to flow into the cell triggering the vesicle to fuse into the membrane
  • Second step of Synapse
    neurotransmitters diffuse across the synaptic cleft to the post-synaptic membrane then bind to the receptors and induces or inhibits an action potentail