Review for Skeletal System Test

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Class Topics
Title Anat Phys 11/8/06
Objectives

• To assess knowledge of the skeletal system and
  learn about the nervous system.

• Review for Skeletal System Test
• Nervous System
• Do what you can, with what you have, where you
  are.
• Theodore Roosevelt

Wednesday, December 16, 2009 306 AM
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Class Assignments
By When
What

• Skeletal System Test 11/8/06
• Read 240-270
• Due this class period
• Due next class period
• Due in the future

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Posttest Activities

• Read 240-270

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Neuroglia (Figure 9-2)

• Astrocytes - CNS - control blood flow
• ependymal cells - CNS - form CSF
• Microglia - CNS - used to clean
• Oligodendrocytes - CNS - used to speed up action
  potentials
• Schwann cells - found in PNS - aids in conduction
  of action potential and helps large neurons

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Neuron Parts

• Cell body
• cytoplasm, nucleus (with nucleolus), and
  organelles
• organelles including Nissl bodies (like RER) and
  lacking mitotic spindles
• Dendrites
• numerous
• conduct action potential towards cell body
• Axon
• single
• conduct action potential away from cell body

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Resting Membrane Potential

• Difference in charge on inside and outside of
  plasma membrane
• unequal distribution of ions
• Ion channels
• integral proteins that regulate ion movement in
  cell membrane
• not only in nerve cells

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Resting Membrane Potential (cont.)

• Ions most often found
• Na, K
• More sodium outside and potassium inside
• this imbalance is kept by the sodium- potassium
  pump
• uses energy to move the ions out/in the cell

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Sodium-Potassium Pump

• Forces Na out and K in the cell
• Creates a concentration gradient
• Na diffuses in and K diffuses out
• Pump doesnt work evenly
• 3 Na for every 2 K
• Creates an electrical gradient with more positive
  charges on the outside
• K diffuses more readily than Na
• Increases the electrical gradient

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• Inside the cell
• Negatively charged
• Lack of positive ions and presence of Cl- ions
• Cell is at resting potential
• Ready to go at stimulus
• POLARIZED
• Voltage
• About 70 mV (millivolts)
• Very small amount
• A D battery has about 1.5 volts