Nervous System:
made up of nervous tissue used for communication throughout the body
cells are elgonated and perform many processes the elgonation helps increase the surface area
there are two fundamental attributes - irritability and conductivity
the ability to react and to transmit

The Central Nervous System:
consists of the brain and spinal cord
contains nerve cells - called neurons
neuroglia- glial cells
it is estimated that there are one hundred billion nerves in the human body
each nerve can recieve a signal from one-thousand nerves and transmit a signal to one-thousand nerves
the impulses of the body are conveyed all over by long processes of axon together
the cells contain a "highly specialized epithelium" but have the same cell junctions and origins

The Peripheral Nervous System:
all nervous tissue outside of the brain and spinal cord
groups of nerve cells - ganglia or cell nests
cells are star-shaped with dendrites extending off of them - these are usually motor neurons which send reflex signals
Ganglia also called “plexus”
Nerves of the brain are called “cranial nerves"

Two basic types of morphology in nerve cells:

1. star-shaped ones with a lot of dendrites are usually called motor neurons/ afferent
   
2. Sensory neurons, which are round, and usually have satellite cells around the outside, bring information in to CNS from PNS.

Cytoplasm that surrounds the nucleus: perisomethin
Many dendrites, one axon (maybe myelinated).
Axon Hillock lacks nissl substance.
Node of Ranvier, is an interruption on the axon.
Pacinian corpuscles are deep touch receptors.
Supportive cells in the nervous system are neuroglia, also called “glial” cells. These are not sensory or motor neurons. Collectively they outnumber neurons in the body by about 10x.
There are two types of neuroglia:
Schwann cells, and satellite cells

Astrocytes, Oligodendrocytes, and Microglia are three other types of glial cells.

Different kinds of astrocytes. Within each glial cell type, there are a wide array of forms that they can take.
Astrocytes: star-shaped, contain a lot of glycogen, called on for nutrients
occur mainly in the grey matter.
Involved in scar forming of the nervous system.
Places where the scar is formed are termed “sclerosis”- the little knot you get.
“Sclerrotized” means cornified.
Oligodendrocytes: produce myelin sheath in CNS
 Microglia: occur throughout the CNS
most common of all glial cell
sometimes called “glialblasts”
totipotent
little black dots you can see within grey matter in spinal cord.
Thought to be able to differentiate into astrocytes and oligodendrocytes.
Garbage collectors within brain as well.
Have long pseudopods that come out and can be cerebral “macrophages”.