Histology lecture Flashcards
What are the three functions of the nervous system?
Sensory inputIntegrationMotor output
Describe the two types of cells found in nervous tissue.
Nerve cells/neurons: main functional cells of the nervous system that generate and transmit action potentialsNeuroglia, glia, or supporting cells:these are much smaller than nerve cell and they have a supportive role
The three special characteristics of neurons are?
Extreme longevity- can function for 100 yearsMost are amiotic- lose their ability to divide as they become communication links in the nervous systemHigh metabolic rate: they will die within a few minutes without oxygen
What goes on in the neuron cell body?
It is the biosynthetic center of the neuron. It makes necessary molecules and sends them down the line
True or false, action potentials are associated with the cell body?
False. They are not
What are Nissl bodies?
clumps of ribosomes
What do the dendrites do?
They are the main receptive/main input regions of the neuron
Are dendrites myelinated? Why or why not?
No- no action potentials here.
What is the purpose of the axon/nerve fiber?
Generation and conduction of action potentials
How many axons can a neuron have?
Just one
A collection of cell bodies in the CNS is called….
a nucleus
A collection of cell bodies in the PNS is called…
a ganglion
What is the axon hillock?
It is kind of the base of the cell body where the axon begins to start- no organelles found here and it’s not myelinated
Where are interneurons found?
Between motor and sensory neurons
How are neurons classified?
By the number of dendritic processes
Which types of neurons are the most abundant?
multipolar
Where are unipolar neurons mainly found?
In the PNS
True or false, multipolar neurons are usually for special sensory?
False- most are for motor function or are interneurons