A&P 2

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A&P 2
2010-05-01 11:10:56
Nervous System

Nervous System
Show Answers:

  1. CNS stands for and is made up of what?
    • Central Nervous System
    • Brain and spinal cord
  2. PNS stands for and is made up of what?
    Peripheral Nervous System

    Nerves and Ganglia (groups of neuron cell bodies outside the cns)
  3. Afferent Division

    Means What?

    towards brain

    sensory NS (visceral and somatic)
  4. Efferent Division

    Means What?

    Away from brain (It takes EFFORT to move muscles)

    Motor NS
  5. Somatic NS

    Means What?

    Soma = Body

    Voluntary NS
  6. Autonomic NS

    Means what?

    Automatic NS (cardiac m etc)

    Visceral NS
  7. Sympathetic NS
    Fight or Flight

    Initiates Stress response
  8. Parasympathetic SN
    rest and repose

    operates during normal relaxed conditions
  9. 3 Functions of the NS
    1-Sensory (Afferent)

    2-Integrative (CNS) Interneurons

    3-Motor (Efferent)
  10. Nervous Tissue

    2 types?
    Neurons-amitotic-cells that transmit the action potentials (nerve impulses)

    Neuroglia- mitotic-cells that support/protect and nourish the neurons
  11. 3 parts to a neuron
    1-Soma Cell body of the neuron

    2-Axon-process that carries the impulse away from the cell body (axon/away)

    3-Dendrite-process that carries impulse towards cell body
  12. 4 types of neurons
    1-Multipolar -1 axon many dendrites

    2-Bipolar- 1 axon and 1 dendrite -rare-

    3-Unipolar- 1 process off cell body that splits into axonic and dendritic processes

    4-anaxonic- many short processes
  13. 2 Functional characteristics of Neurons
    1-Excitability- ability to recieve and respond to a stimulus

    2- Conductivity- ability to transmit an impulse
  14. Resting Membrane potential is
    -70 mV
  15. 4 Steps in Action Potential
    1-Depolarization- when the Na+ gates open and depolarized from -70mV to 0mV

    2-Reverse Polarization-So much Na+ that for instant membrane is positive

    3-Repolarization- when K+ gates open and cell is back to -70mV

    4-Sodium-potassium pump- cell being reset
  16. Refractory Periods (2)
    Absolute Refractory Pd- pd of time cell ABSOLUTLEY cannot fire because it hasnt been reset enough

    Relative refractory Pd- pd of time it takes a larger than normal stimulus to fire b/c cell is only partially reset
  17. Threshold is
    The minimum stimulus needed to achieve an action potential
  18. All or None Prinicipal is
    Nerves fire completely and as hard as they can.....there are NO weak nerve firings
  19. Schwann cells produce and are a part of what?
    Myelin and PNS
  20. Nodes of Ranvier
    gaps in myelin sheath
  21. Continuous conduction is
    Type of conduction in UNMYELINATED nerve fibers
  22. Saltatory conduction is
    LEAPING conduction in myelinated fibers
  23. A Neurilemma is
    Nerve cell membrane
  24. Synapse is
    region of communication between 2 neurons
  25. Synaptic Cleft is
    fluid filled space between pre and post synaptic neurons
  26. Excitatory transmission
    reaction between neurotransmitter and receptor depolarizes post synaptic membrane- EXCITES nerve firing
  27. Inhibitory Transmission
    Reaction between neurotransmitter and receptor-hyperpolarization of membrane- INHIBITS nerve firing
  28. 3 types of circuits
    1-Single series- 1 neuron synapses with another single neuron

    • 2-Divergence circuit- 1 neuron synapses with multiple neurons (DIVERGES)
    • 3-Convergence Circuit- many neurons synapse with a single neuron. (CONVERGES)
  29. 5 basic components of typical reflex are

    2-afferent neuron-sensory


    4-Efferent neuron-motor


    Random Acts Include Empathetic Elephants
  30. A Nerve Fiber is
    individual axon or dendrite
  31. A Endoneurium is
    CT covering surrounding single nerve fiber and its neurilemma
  32. A fascicle is
    bundle of nerve fibers
  33. A Perineurium is
    ct covering surrounding fascicle
  34. Epineurium is
    CT covering surrounding entire nerve
  35. Do nerves have blood vessels?
    Yes...because of high demand for energy