Muscle and neural tissues

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Muscle and neural tissues

  1. 1. Muscle and Neural Tissues
  2. 2. Muscle <ul><li>Specialized for contraction </li></ul><ul><li>Actin & myosin </li></ul>
  3. 3. Skeletal Muscle <ul><li>Striated </li></ul><ul><li>Voluntary </li></ul><ul><li>Large cells </li></ul><ul><li>Fasciae </li></ul><ul><li>Multinucleate </li></ul><ul><li>Nerve stimulated </li></ul><ul><li>Attached to bones </li></ul>
  4. 4. Cardiac muscle <ul><li>Striated </li></ul><ul><li>Involuntary </li></ul><ul><li>Single nucleus </li></ul><ul><li>Intercalated disks </li></ul><ul><li>Branching </li></ul><ul><li>Pacemaker cells </li></ul><ul><li>Heart </li></ul>
  5. 5. Smooth muscle <ul><li>Nonstriated </li></ul><ul><li>Involuntary </li></ul><ul><li>Spindle shaped cells </li></ul><ul><li>Single nucleus </li></ul><ul><li>Hormone or nerve stimulation </li></ul><ul><li>peristalsis </li></ul><ul><li>Hollow organs </li></ul>
  6. 6. Neural Tissue <ul><li>Conduct impulses </li></ul><ul><li>Brain </li></ul><ul><li>Spinal cord </li></ul><ul><li>Peripheral nerves </li></ul>
  7. 7. Neural Tissue <ul><li>Neurons </li></ul><ul><ul><li>1 meter </li></ul></ul><ul><ul><li>Dendrites </li></ul></ul><ul><ul><li>Soma </li></ul></ul><ul><ul><li>Axon </li></ul></ul><ul><ul><li>Synaptic (axon) terminals </li></ul></ul><ul><li>Neuroglia </li></ul><ul><ul><li>Support cells – phagocytic, isolation, framework, connect to blood vessels </li></ul></ul>
  8. 8. Neuron diagram
  9. 9. Action Potential (impulse) <ul><li>Stimulus produces electrical impulse </li></ul><ul><li>affects cell membrane of the dendrite </li></ul><ul><li>alters membrane properties of soma </li></ul><ul><li>produces massive change in transmembrane potential </li></ul><ul><li>sweeps along the length of the axon </li></ul><ul><li>Skips along Nodes of Ranvier in between myelin </li></ul><ul><li>to synaptic terminals </li></ul>
  10. 10. Synapse - junction between nerve cells, a very small gap <ul><li>impulse reaches synaptic terminals </li></ul><ul><li>release of a chemical neurotransmitter </li></ul><ul><li>Acetylcholine is the neurotransmitter for muscle stimulation, dopamine and serotonin are others </li></ul><ul><li>crosses synapse by diffusion and contacts the adjacent cell membrane </li></ul><ul><li>Next cell may be another neuron or some other cell (muscle, gland) </li></ul>
  11. 11. Curare <ul><li>a poison used by Native Americans </li></ul><ul><li>Curare binds to acetylcholine receptors and blocks them </li></ul><ul><li>Muscles are paralyzed by being stuck in the relaxed state </li></ul><ul><li>Cholinesterase is an enzyme which breaks down acetylcholine and stops a contraction </li></ul>
  12. 12. Tetanus <ul><li>A toxin that travels backwards through neurons to the spinal cord </li></ul><ul><li>Blocks inhibiting neurons </li></ul><ul><li>Causes muscles spasms and tetanii (extended contractions) that can tear muscles </li></ul>

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