Card Set Information
what are the 3 distinct segments of neurons?
1.cell body or perikaryon
(dentrites and axon are collectively referred to as processes)
what is the difference between nerve process and nerve fiber?
is and extension of neuron cell body
refers to a process and
what is a cell body or perikaryon?
the main ventral portion of the cell
what does a cell body or perikaryon contain?
it contains most of cytoplasm, nucleus, and "most" typical cell organelles
what does the cell body or perikaryon do? and what does it not have?
a. it carries on metabolism for entire cell
b. no centrioles-> can not produce mitotic apparatus
what are 2 structures unique to neurons?
b. nissl bodies or nissl substance
what are neurofibrils?
small fibrils(filaments) composed of microtubules and intermediate filaments
where are neurofibrils found?
found in the cell body and extend into the processes
what is the function of neurofibrils?
they function as an internal skeleton and transport routes
what do nissl bodies or nissl substance appear as?
they appear as orderly arranged granules in the cell body and dendrites but not axons
what do nissl bodies or nissl substance consist of?
they consist of rough ER and accumulated product (protein)
what is the condition of nissl bodies or nissl substacnces?
their conditions change with conditions of the neuron
what happens to nissl substance after neuron damage?
what happens during repair?
large amounts of nissl substance appear
what is the structural description of dendrites?
short, thick, highly branched extensions of the cell body-> usually several per neuron
what is the functional description of dendrites? (most important description)
picks up nerve impulses and carries them to neuron cell body
what is the structural description of an axon?
a single, thin, long process origination from the "axon hillock" of cell body(conical portion of cell body)
an axon may branch forming what?
how to axons terminate?
they terminate in fine filaments->telodendrin
what are on the ends of telodendria that are enlargements? (axon)
what is the functional description of an axon(most important description)?
carries nerve impulse away from neuron cell body to another neuron or and effector