Monica Hurtado
Taylor Gallo
Vanessa Alfaro
Steven Nuno
Period:2
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Function: To sense changes in their surroundings and
respond by transmitting nerve impulses along cellular
processes to other neurons or to muscles and glands.
◦ The complex patterns in which the neurons connect with each other and
with muscle and gland cells they can coordinate, regulate, and integrate
many body functions.
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Structure:
◦ Dendrites are treelike extensions that help increase the surface area of the
cell body. They receive information from other neurons and transmit
electrical stimulation to the soma.
◦ The soma is where the signals from the dendrites are connected and
passed on.
◦ The axon hillock is located at the end of the soma and controls the firing
of the neuron.
◦ The axon is the elongated fiber that extends from the cell body to the
terminal endings and transmits the neural signal.
◦ The terminal buttons are located at the end of the neuron and are
responsible for sending the signal on to other neurons.
◦ Synapse is a located at the end of the terminal button .Neurotransmitters
are used to carry the signal across the synapse to other neurons.
Structural differences:
1.Bipolar neurons:
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Cell body of a bipolar neuron has only two processes, one rising from wither end
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One is an axon and the other is a dendrite.
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Found within specialized parts of the eyes, nose, and ears.
2. Unipolar neurons
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Single process extending from its cell body.
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Process divides into two branches, but functions as a single axon.
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Cell bodies of cell unipolar neurons aggregate in specialized masses of neuron tissue
called ganglia, which are located outside of the brain and spinal cord.
3. Multipolar neurons
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Many processes arising from their cell bodies.
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Only one is an axon the rest are dendrites.
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Most neurons that cell bodies lie within the brain or spinal cord are of this type.
4.Pyramidal neurons
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The cell body, or soma of the pyramidal neurons has a distinct shape that gives them
their name.
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In fish, birds, reptiles and mammals.
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Made up of a cell body attached to an axon and dendrites.
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Both the axon and dendrites undergo extensive branching.
Functional differences:
1.Sensory Neurons
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Carry nerve impulses from peripheral body parts to the brain or in spinal cord.
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At their ends the dendrites of these neurons or specialized structures associated with
them act as sensory receptors, detecting changes in the outside world or within the
body.
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When stimulated, sensory receptors trigger impulses that travel on sensory neuron
axons into the brain or spinal cord.
2. Interneurons
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Lie within the brain or spinal cord
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Multipolar and form links between other neurons
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Transmit impulses from one part of the brain or spinal cord to another.
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May direct incoming sensory impulses to appropriate regions. Other incoming impulses
are transferred to motor neurons.
3.Motor neurons
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multiploar and carry nerve impulses out of the brain or spinal cord to effectors;
structures that respond, such as muscles or glands.
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Neuroglial Cells
◦ Structure and function
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Referred to as glial cells
Different from nerve cells
Don’t participate directly in synaptic interactions
Maintain the signaling abilities of neurons
Surrounds and supports neurons that are in the central nervous system
Main function is to insulate neurons from each other
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6 types
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oligodendrocytes
astrocytes
ependymal cells
microglia
schwann cells
satellite cells
Possesses slender cytoplasmic extensions. Many axons in
the CNS are completely sheathed in this process.
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Nervous system- The system of nerves and nerve centers(the
brain, spinal cord, nerves, and ganglia)
◦ Peripheral:
 Nervous system that consists of the nerves and ganglia outside of the brain and
spinal cord
◦ Autonomic:
 System of nerves and ganglia that control involuntary functions, consisting of
sympathetic and parasympathetic portions
 Also known as the involuntary nervous system
 Controls visceral functions
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Heart rate
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Digestion
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Salvation
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Respiratory rate
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Travels down the axon
There is a change in polarity across membrane.
The sodium channels open and sodium moves into axon.
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Is not an equilibrium potential.
Relies on the constant expenditure of energy.
Nothing stimulated to the nerve impulse.
Negative sign is the inside of the cell which is due to negative
charges in the cell membrane.
Sodium ions and potassium ions diffuse across the cell
membrane.
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Is a positive going change in a cell’s membrane potential.
In neurons and other cells, a large enough depolarization
may result in an action potential.
Hyperpolarization is the opposite of depolarization.
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Is a change in a cells membrane potential that
makes it more negative.
Opposite of depolarization.
It inhibits action potentials by increasing the
stimulus required to move the membrane potential
to the action potential threshold.
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Level where the membrane potential must be
depolarized in order to initiate an action potential.
Regulate and propagate signaling in both the
central and peripheral nervous system.
“fires up” an action potential.
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The refractory period is a nerve impulse condition
is when neuron responds or not.
When it does respond it responds fully.
The neurotransmitter has acetylcholine
The acetycholine stimulates skeletal muscle
contraction.
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http://www.innerbody.com/image/nervov.html
http://people.eku.edu/ritchisong/301notes2.htm
http://www.ncbi.nlm.nih.gov/books/NBK10869/
http://blustein.tripod.com/
http://www.britannica.com/EBchecked/topic/279678/hyperp
olarization
http://faculty.washington.edu/chudler/ap.html
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