Nervous Tissue

  1. endocrine system
    communicates with chemicals
  2. nervous system
    electrical and chemical to send messages
  3. neurobiology
    study of nervous system
  4. central nervous system (cns)
    consists of the brain and spinal cord
  5. periperal nervous system (pns)
    • everything besides spinal cord and brain
    • afferent and efferent division->somatic and visceral<-( sympathetic and parasympathetic divisions)
  6. Properties of Neurons
    • excitability
    • conductivity
    • secretion
  7. Functional classes of neurons
    • sensory-get
    • interneurons-process
    • motor-respond
  8. neurosoma
    • control center of neuron
    • aka soma or cell body
  9. neurofibrils
    bundles of actin filaments
  10. nerve
    • bundle of nerve fibers (axons) wrapped in fibrous connective tissue
    • carry signals to body parts
  11. ganglion
    knotlike swelling in a nerve where the celll bodies of neurons are concentrated
  12. dendrites
    branches of of soma
  13. axon hillock
    • mound where the axon originates
    • trigger zone
    • where neuron first generates action potentioals
  14. axon
    • originates from axon hillock
    • specialized for rapid conduction of nerve signals to points remote from the soma
  15. axoplasm
    axon's cytoplasm
  16. axolemma
    axon's membrane
  17. terminal arboriztion
    extensive complex of fine branches
  18. synaptic knob
    • end of terminal arborization
    • forms junction with a muscle cell, gland cell, or another neuron
  19. multipolar neurons
    one axon and 2+ dendrites
  20. bipolar neurons
    one axon and one dendrite
  21. unipolar neurons
    single process leading away from the soma
  22. anaxonic neurons
    • multiple dendrites but no axon
    • found in brain, retina, and adrenal medulla
  23. Neuroglia
    • protect neurons and aid their functions
    • aka glial cells
  24. oligodendrocytes
    make up myelin sheath
  25. ependymal
    produce significant fraction of the cerebrospinal fluid
  26. microglia
    • small macrophages that develop from stem cells related to the white blood cells called monocytes
    • concentrated in areas damaged by infection, trauma or stroke
  27. astrocytes
    • most abundant glial cells in cns
    • make 90% of tissue in some areas of the brain
  28. Schwann cells
    • make up neurilemma
    • aka neurilemmocytes
  29. Satellite cells
    • surround neurosomas in ganglia of the pns
    • provide electrical insutlation around the soma and regulate the chemical environment of the neurons
  30. Myelin
    insulating layer around a nerve fiber
  31. chemical synapse
    where presynaptic neuron releases a neurotransmitter to stimulate the postsynaptic cell
  32. electrical synapse
    • connects some neurons, neuroglia, and cardiac/single unit smooth muscle cells
    • adjacent cells are joined by gap junctions that allow ions to diffuese directly from one cell into the next
    • advantage of quick transmission
  33. neural pools
    ensembles of functioning neurons
  34. neural circuits
    • diverging-one fiber branches and synapses with several poststynaptic cells
    • converging circuit- opposite of diverging circuit
    • reverberating circuit-neurons stimulate each other in a linear swquence, but c sends axon collateral back to a (A->B->C->D)
    • parallel after-discharge circuit- input neuron diverges to stimulate several chains of neurons
  35. Neural plate
    gives rise to most neurons and to all glial cells except microglia
  36. neural groove
    thickened edges of neural plate
  37. neural fold
    raised fold along each side
  38. neural crest
    gives rise to most of pns includint sensory and autonomic nerves and ganglia
Card Set
Nervous Tissue
Nervous Tissue