Nervous system 12.2

1.  Nervous tissue is composed of two types of cells, neurons and glial cells.
2. Glial cells, or glia, are known to play a supporting role for nervous tissue. 
3. Neurons are important, but without glial support they would not be able to perform their function.
4. Neurons are responsible for the electrical signals that communicate information about sensations, and that produce movements in response to those stimuli, along with inducing thought processes within the brain.
5. There are 3 types of neurons cell.
6.  Unipolar cells have one process that includes both the axon and dendrite. 
7. Bipolar cells have two processes, the axon and a dendrite. 
8. Multipolar cells have more than two processes, the axon and two or more dendrites.
9. The other processes of the neuron are dendrites, which receive information from other neurons at specialized areas of contact called synapses.
10. There are six types of glial cells. Four of them are found in the CNS and two are found in the PNS.
11. Satellite cell found in PNS the function is support the neuron.
12. Astrocyte found in CNS its support neurons
13. Oligodendrocyte found in CNS it function insulation, myelination.
14. Schwann cell found in PNS its function Insulation and myelination.
15. Ependymal cell it creating CSF .
16. Microglia found in CNS it function immune surveillance and phagocytosis.
17. Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells.
18. Nutrient molecules, such as glucose or amino acids, can pass through the BBB, but other molecules cannot. 
19. Where the axon emerges from the cell body, there is a special region referred to as the axon hillock.
20. The main part of a neuron is the cell body, which is also known as the soma (soma = “body”).
21.