1. November 20-21, 2014

3. Researchers estimate that the brain has 10X as many glial cells as neurons But see this

4. All nervous tissue cells except neurons are known as neuroglia, or glial cells. “nerve glue”

5. Astrocytes (star-cell)  Exchange nutrients between blood and neurons  protect neurons from harmful materials.  “blood brain barrier”  Control flow of blood through brain (what is measured in MRI)  Control extracellular environment  change shape  release calcium and ‘glial transmitters’; uptaking ions and neurotransmitters  Digest waste  Moderate the behavior of neurons Astrocytes are the most abundant glial cell and may be the cells responsible for thought

6. Microglia  Shaped like astrocytes, but smaller, and don’t connect neurons to blood vessels  Digest debris, bacteria, and dead brain cells Ependymal Cells  Line the cavities of the brain and the spinal cord  Produce and circulate cerebrospinal fluid

7. Oligodendrocytes  Wrap around axon of CNS neurons, creating a fatty myelin sheath that insulates neurons  Each oligodendrocyte wraps around the axons of several neurons  Allow for efficient nerve impulse propagation Multiple sclerosis (MS) is an autoimmune disease characterized by the gradual destruction of the myelin sheath

10. Schwann Cells  Form myelin sheaths around peripheral neuron axons  Many Schwann cells per neuron  Give peripheral neurons some ability to regenerate Satellite Cells  Surround body of peripheral neurons  Function not fully understood – may have similar function as astrocytes??

11. Scholar whose birthday is earlier in the month...  Identify the two PNS glial cells, determine which cells in the CNS have similar function, and describe the similarities and differences in each pair of cells. Scholar whose birthday is later in the month …  Identify two similarities and one difference between astrocytes and microglia  Explain the location and function of ependymal cells

13. The cell body contains the nucleus and organelles Nissl substance is rough ER Neurofibrils are intermediate filaments

14. Processes carry information. Dendrites receive and carry messages towards the cell body. The axon generates messages and usually carries them away from the cell body. There may be 100’s of dendrites, but only 1 or 2 axons. The end of the axon branches into 100’s or 1000’s of axon terminals

15. Schwann cells wrap around most PNS axons, forming the myelin sheath. Nodes of Ranvier are gaps in the myelin sheath / spaces between Schwann cells. What cells cover the axons of CNS neurons? What cells cover the body of PNS neurons?

16. Schwann cells wrap around most PNS axons, forming the myelin sheath. Nodes of Ranvier are gaps in the myelin sheath / spaces between Schwann cells. What cells cover the axons of CNS neurons? oligodendrocytes What cells cover the body of PNS neurons? Satellite cells

17. Afferent neurons carry sensory information to the CNS. Interneurons connect sensory and motor neurons in the CNS. Efferent neurons carry messages from the CNS to muscles or glands.

18. The cell bodies of afferent neurons are found in the PNS in clusters called ganglia. The cell bodies of efferent and interneurons are found in the CNS in clusters called nuclei.

19. Neurons can also be classified by the number of extensions of the cell body. Multipolar neurons have 3 or more extensions Bipolar have 2 extensions Unipolar have 1 short extension, which branches into two axons

20. Write one question that you think might be on an exit ticket on the front of a note card. It should be something that can be answered in a sentence of less. Write the answer on the back.

21. Homework:  Read chapter 7  Quiz 12/5 -12/8

22.  What were our objectives and what did you learn about them?  What was our learner profile trait and how did we exemplify it?  How does what we learned today relate to our unit question?