BIOL 2113 – Chapter 12: The Nervous System and Nervous Tissue Study Guide
Topic
Identify the basic functions
of the Nervous System
Explanation
1.Sensation- environment around us.
2.Integration-association area
3.Response-motor functions
Describe the components of
the central and peripheral
nervous system.
Central nervous system – consists of the brain and spinal cord
Peripheral nervous system –all the nerves that branch out from the brain and the
spinal cord and extend to other parts of the body including muscles and organs
Describe the structure of a
neuron.
Extending from the cell body are short, branched dendrites which receive chemical
signals from other neurons or stimuli that initiate an electrical signal. ... The neuron
consists of a cell body, dendrites, and an axon. Information flows from the dendrites to
the cell body, and then on down the axon to its terminal.
Discuss the functional types
of neurons (may not be in
the text).
1. Sensory neurons- the nerve cells that are activated by sensory input from the
environment - for example, when you touch a hot surface with your fingertips, the
sensory neurons will be the ones firing and sending off signals to the rest of the
nervous system about the information they have received.
2. Motor neurons- are neuronal cells located in the central nervous system (CNS)
controlling a variety of downstream targets.
3. Interneurons- central nodes of neural circuits, enabling communication between
sensory or motor neurons and the central nervous system (CNS). They play roles in
reflexes, neuronal oscillations, and neurogenesis in the adult brain.
Discuss the structural types
of neurons.
1. Unipolar neurons- one process, called a neurite, extends from the cell body
2. Bipoloar neurons- has two extensions (one axon and one dendrite).
3. Multipolar neurons- possesses a single axon and many dendrites (and dendritic
branches), allowing for the integration of a great deal of information from other
neurons.
Identify and discuss the glial
cells of the CNS.
1.Atrocyte- star shaped connect neurons to blood vessels
Topic
Explanation
2.Microglial- phagocytic
3.Ependymal- Line cavities containing cerebro spinal fluid
4.Oligodendrocytes-myelinate axons (coats axon)
Identify and discuss the glial
cells of the PNS.
1.Sattelite Cells-support ganglia(cluster of cell bodies)
2.Schwann Cells- Myelinate axons in pns
Define synapse and describe
the events that occur at the
synapse.
A junction that mediates information transfer from one neuron to the next or from a
neuron to an effector cell
Describe an action potential,
its generation, and
An action potential is generated in the body of the neuron and propagated through its
transmission.
axon. ... Because of this, an action potential always propagates from the neuronal
body, through the axon to the target tissue. The speed of propagation largely depends
on the thickness of the axon and whether it's myelinated or not.
Discuss the “all-or-none”
principle of action
potentials.
The all-or-none law is the principle that the strength by which a nerve or muscle
fibergggyu0-rev responds to a stimulus is independent of the strength of the
stimulus. ... If that stimulus exceeds the threshold potential, the nerve or muscle fiber
will give a complete response; otherwise, there is no response.
Describe the following:
Excitatory Postsynaptic Potential (EPSP) – postsynaptic potential that makes the
postsynaptic neuron more likely to fire an action potential. ... When multiple EPSPs
occur on a single patch of postsynaptic membrane, their combined effect is the sum of
the individual EPSPs.
Inhibitory Postsynaptic Potential (IPSP) – kind of synaptic potential that makes a
postsynaptic neuron less likely to generate an action potential
Topic
Explanation
Spatial summation – the effect of triggering an action potential in a neuron from one
or more presynaptic neurons. This occurs when more than one excitatory postsynaptic
potential (EPSP) originates simultaneously and a different part of the neurone.
Temporal summation – occurs when a high frequency of action potentials in the
presynaptic neuron elicits postsynaptic potentials that summate with each other.
Discuss neuron regeneration
(not in textbook).
regeneration and repair in the nervous system is a process by which damaged tissue
undergoes regrowth or renewal, leading to eventual restoration of nervous system
function. This process happens more readily with axons, synapses, neurons and glia in
the peripheral nervous system.
Discuss the following
common neurotransmitters
(be sure to identify as
excitatory or inhibitory as
well as general type of
chemical category):
Acetylcholine – excitatory neurotransmitter secreted by motor neurons that innervate
muscle cells, basal ganglia, preganglionic neurons of the autonomic nervous system,
and postganglionic neurons of the parasympathetic and sympathetic nervous systems.
Its main function is to stimulate muscle contraction.
Serotonin – inhibitory neurotransmitter that is involved in emotion and mood,
balancing excessive excitatory neurotransmitter effects in your brain.
Dopamine – both excitatory and inhibitory. Dopamine helps with depression as well as
focus, which you will read about in the excitatory section. DOPAMINE is our main focus
neurotransmitter.
Norepinephrine and epinephrine – excitatory action are acetylcholine, norepinephrine,
and epinephrine while GABA is the major inhibitory neurotransmitter.
Describe these disorders
(you may have to research
beyond your text).
Multiple sclerosis – potentially disabling disease of the brain and spinal cord (central
nervous system) the immune system attacks the protective sheath (myelin) that covers
nerve fibers and causes communication problems between your brain and the rest of
your body.
Guillain-Barre – rare disorder in which your body's immune system attacks your
nerves. Weakness and tingling in your extremities are usually the first symptoms.
These sensations can quickly spread, eventually paralyzing your whole body.
Alzheimer’s disease – degenerative brain disease and the most common form of
dementia. Dementia is not a specific disease
Topic
Explanation
Parkinson’s disease – progressive nervous system disorder that affects movement.
Symptoms start gradually, sometimes starting with a barely noticeable tremor in just
one hand
Creutzfeld-Jacob disease – disease is a degenerative brain disorder that leads to
dementia and, ultimately, death. Symptoms of Creutzfeldt-Jakob disease (CJD) can
resemble those of other dementia-like brain disorders, such as Alzheimer's. But
Creutzfeldt-Jakob disease usually progresses much more rapidly.