Brain Cells

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Neurons

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Neurons are part of the nervous tissue and are very complex cells that can communicate with many thousand other neurons, tissues, cells and glands. They send messeges to and from the brain at high rates of speed. The neuron is made up of a cell body, which contains the nucleus. Structures that branch off of the cell body are called the dendrites; These structures are the signal recievers. A larger structure that branches off from the cell body is the Axon, which regulates the nerve signals. The myelin sheath is the fatty structure that covers the axon and acts as a catalyst for transmissions. Along the axon are spots that are not covered with myelin, called nodes of ranvier. Axon terminals are located at the end of the axon. These terminals transmit chemical signals across the synapse, which is a space between the axon terminal and a receiving cell.
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There are three different types of neurons: Sensory neurons, Motoneurons and Interneurons. Sensory neurons, also known as bipolar neurons, send and recieves messages with the sensory receptors, to and from the Central Nervous System (CNS). Motoneurons, also known as multipolar neurons, take the messages from the CNS and carry them to glands. Interneurons, also known as pseudopolar cells, form the internal makeup of the CNS. They also have two axons instead of an axon and dendrites.
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How Neurons Grow In The Brain from Cevriye Arzu Aydoğan on Vimeo.



Glial Cells or Neuroglia Cells

external image neuroglia_of_CNS.gifMeaning "Nerve Glue" these cells don't transmit nerve impulses like the neurons. Instead these cells support and protect the neurons. There are many of them and can go through mitosis. There are five types of glial cells: Schwann cell, Satellite cells, microglia, oligodendroglia and astroglia.
Schwann cells wrap themselves around the axon, basically creating the myalin, while oligodendroglia cells wrap around more than one axon at a time. They also help in the regrowth of neurons. Satellite cells mediate and repair skeletal muscle tissue and are believed to be the "committed stem cells of adult skeletal muscle" (
http://www.brown.edu/Courses/BI0032/adltstem/sc.htm) . Microglia cells are the first line of immune defense in the brain and spinal chord. Astroglia are found the most out of the glial cells and have been known to function in metobolic brain functions, homeostasis of the brain and neurotransmitting, naming just a few.

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1. Shwann cell

2. Oligodendroglia cells

3. Satellite cells

4. Microglia cell

5. Astroglia Cell (green)

Resources

http://www.daviddarling.info/encyclopedia/N/neuron.html (image)


http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml


http://www.siumed.edu/~dking2/ssb/neuron.htm (image)


http://gerardkeegan.com/glossary/interneurons (image)


http://blustein.tripod.com/Schwann_Cells/schwann_cells.htm


http://www.brown.edu/Courses/BI0032/adltstem/sc.htm


http://www.microglia.org/Microglia/Microglia.html


http://neuro.psychiatryonline.org/cgi/content/full/20/2/iv


http://www.google.com/imgres?


http://medical-dictionary.thefreedictionary.com/Microglial+cell (image)


http://newsroom.stemcells.wisc.edu/gallery/neurons_astroglia05.html (image)


http://brainfunctionss.com/2011/08/15/brain-cells/ (image)


http://vimeo.com/7488538

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