Nervous System Flashcards
What is the Nervous System made up of?
Neurons + glial cells
1) What is the neuron?
2) What are the glial cells and what are they involved in?
1) functional cell of NS
2) supporting cells - they wrap axons in myelin
What 3 actions is the neuron involved in?
1) receives excitation (at a synapse or receptor) or becomes excited
2) conducts excitation along an axxon
3) transmits excitation (via release of chemical at synapse)
What is a multipolar neuron?
the cell body is located where input excitation occurs (in center of receptor region)
What is a unipolar neuron?
the cell body is located along the axon (in a spinal ganglion)
Are most neurons multipolar or unipolar?
multipolar
- Label which neuron is mutlipolar and unipolar
- Label all the structures of each neuron.
Answers:
- Multipolar
- unipolar
- dendrites
- cell body
- axon
- synapse
- receptor
- axon
- cell body
- synapse
True or False:
Sensory neurons are multipolar.
False
Sensory neurons are unipolar
Excitable cell =
polarized plasma membrane
Define excitation
flow of ions across plasma membrane (membrane breaks down to allow ion flow)
What drives the flow of ions?
electrical gradient and ionic mileu
In unipolar neurons…
1) what does the receptor act as?
2) what triggers excitability
1) conducer
2) environmental energy
What are neurons dependent on?
local environment of ions
Define these terms:
1) nerve
2) root
3) ganglion
1) bundle of axons ensheathed by supporting cells adn enveloped by connective tissue
2) nerve that is adjacent to the CNS adn eveloped by meninges
3) localized site where a nerve is enlarged due to a collection of cell bodies
1) Name the two types of ganglia
2) Name which type of cell body each contain
1) spinal ganglia:
unipolar cell bodies
2) autonomic ganglia:
mutlipolar cell bodies
True of False:
Autonomic ganglia have synapses on them
True
they contain multipolar cell bodies which are located next to synapses
Where are spinal ganglia located?
on dorsal roots of cell bodies
What do autonomic ganglia innervate?
viscera