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BIOL 2010 Human Anatomy & Physiology I
What are the functions of the Nervous System?
• _____ ________
(environment & self)
• Conduct ________
• _________
&
__________ impulses
(stimuli)
• __________
What are the functions of the Nervous System?
Out of this comes
_________, & ability
to ___________
How is the Nervous System organized?
________
______ _____
________
______ _____
Central Nervous
System (CNS)
Peripheral
Nervous System
(PNS)
43:
( ___ cranial &
___ spinal nerves)
How is the Nervous System organized?
CNS
____
Afferent
_________
Somatic
____________
Sympathetic
_____________
What are the Structural/functional units
of the Nervous System?
• Nerve cells ~ _______
• Maintaining cells ~
______ ______
Neuron anatomy:
___________________
____________
_________
What are the different types of Neurons?
Structural types: Functional types:
________
______
________
Association ~
Interneurons
Afferent ~ Sensory
neurons
Efferent ~ Motor
neurons
What are the types of glial cells and what
tasks do they accomplish?
___________:
control substances
entering/leaving
CSF
Associated with
_______________
which is formed by
endothelial cells of
blood vessels.
What are the types of glial cells and what
tasks do they accomplish?
_______________:
Line the ventricles
(cavities) of CNS,
create cerebral
spinal fluid and aid
in its circulation.
What are the types of glial cells and what
tasks do they accomplish?
_____________:
Small specialized
macrophages that are
attracted to areas of
damage in the CNS
and phagocytize
debris
What are the types of glial cells and what
tasks do they accomplish?
________________:
Cells in the CNS that
have multiple
extensions that wrap
around multiple
axons forming
myelin sheaths.
What are the types of glial cells and what
tasks do they accomplish?
_______________:
Cells in the PNS that
wrap around single
axons forming
myelin sheaths.
The gaps in between
Schwann cells are
called ______ __
___________
What are the differences between Myelinated
and Unmyelinated Neurons?
_______________:
Action potential
occurs along entire
plasma
membrane…
________
_______________:
Action potentials
jump from one node
to the next…
_________
What is Saltatory Conduction and why is it
important?
Thick myelin
sheaths insulate
plasma membrane
and force “jumping”
(__________)
movement of
electrical charge
(action potential)
____________
effects myelin
sheaths in CNS
How can you tell if nervous tissue is myelinated?
Myelin sheaths contribute
to white appearance =
_____ _________
Neuron cell bodies and
dendrites contribute to a
darker color = _______
__________
Clusters of cell bodies are
called _______ or _____
in the PNS and the CNS
respectively
How are signals sent along the axon highway?
Make sure you are comfortable with:
• Establishment of resting potentials
• Formation and propagation of action
potentials.
• Mechanisms involved with conducting
action potentials between cells
(Intercellular action potential propagation).
BI 201 Human Anatomy & Physiology
How does the body generate electric potential?
Electric signals (called
_______________) are
essential to nerve cell
function and muscle
contraction.
Refer to tables 11.2, 3 & 4
BI 201 Human Anatomy & Physiology
How does the body maintain electrical
gradients?
_________ with “-” charge
stuck inside cells
• __________ channels
that allow K+ to diffuse in Non-gated
or out of the cell
• Very few Na+ ions can
diffuse through cell
membrane EXCEPT via
_____________
• ___________ contributes
to gradient
Gated
BI 201 Human Anatomy & Physiology
How does the body maintain electrical
gradients?
•As K+ diffuse out they
leave ____________ inside
the cell and develop an
electric potential. When
the “-” attraction inside the
cell is = to the tendency for
K+ to leave then
__________ is established.
•Usually around -70 to -90
mVolts… called _______
___________
BI 201 Human Anatomy & Physiology
What are the 2 primary ways to change the
resting potential?
1)
2)
Decrease potential…
_____________
(hypopolarization)
Increase potential…
_____________
BI 201 Human Anatomy & Physiology
Take 5!!!
What would the effect on the resting
membrane potential be if the
permeability of the plasma membrane
to K+ was reduced? Why?
Discuss with your
neighbor and predict
an answer.
BI 201 Human Anatomy & Physiology
What is the effect on the resting potential that results
from changing Na+ concentrations?
Change in Na+ ion
concentration
DOESN”T have
much effect
Change in
permeability DOES
Why?
BI 201 Human Anatomy & Physiology
What properties make some cells electrically excitable?
Cells such as muscle and
nerve cells have >#...
Depolarization causes the ___
channels to open quickly…
(___ open more slowly and
close more slowly)
BI 201 Human Anatomy & Physiology
What about the effects of Ca2+ ions on the
resting potential?
When extracellular
Ca2+ ions are reduced
then they _________
_____ ______
(including gated Na+
channels, which causes
them to open).
What is the result of
Hypocalcemia?
Ca 2+
BI 201 Human Anatomy & Physiology
Are there any potentials other than resting
potentials?
A localized stimulus usually causes… a _____
_______ (change in resting membrane potential).
Can be caused by:
1)
2)
3)
4)
5)
BI 201 Human Anatomy & Physiology
What are the properties of local potentials?
Changes in the
resting potential
can be at
different levels
of magnitude,
i.e. ________
Influence of
local potentials
can be
increased by
___________
Local potentials taper off as they move
away from the stimulus source
(see table 11.3)
BI 201 Human Anatomy & Physiology
Do local potentials have any potential?
If the threshold potential is
reached… then an _______
_________ results
3 phases:
These are propagated along
the plasma membrane and
are “_____________”
Below the threshold = local
potential ~ “______”
Above the threshold =
action ~ “______”
(see table 11.4)
BI 201 Human Anatomy & Physiology
How do those waves correlate with cellular
reality?
BI 201 Human Anatomy & Physiology
What happens after all the excitement?
Refractory period
Until the voltage gated
channels return to the
resting state, no further
action potential is possible.
When totally
insensitive…then ________
__________ _________
BI 201 Human Anatomy & Physiology
How do action potentials move along a cell?
What keeps
the action
potential
from
reversing
direction?
BI 201 Human Anatomy & Physiology
What about getting the electrical “message”
(action potential) to the next cell?
Generally accomplished
via _________ _________
If ligand opens Na+
channels then…
If ligand opens K+
channels then…
BI 201 Human Anatomy & Physiology
What about getting the electrical “message”
(action potential) to the next cell?
Cardiac & smooth muscle
tissue have _________
____________.
Action potentials can be
propagated across
adjacent cells via the ___
_________, which allow
ions to pass through.
BI 201 Human Anatomy & Physiology
Do all neurons respond to continued
stimulation equally?
Some neurons will
continue to maintain a
local potential sufficient
to initiate action
potentials.
other neurons begin to
become insensitive to
continued stimulus and
the frequency drops off
until the local potential
drops below threshold
(_____________).
How are signals sent along the axon highway?
In addition to
neurotransmitters,
there are also
________________
(w/c influence
_________ of pre- or
post-synaptic
membrane)
Example: ___________, w/c when bound w/
receptors on pre-synaptic neurons limit
neurotransmitter release (see table 11.5)
What is the difference between Excitatory &
Inhibitory neurons?
Ligands binding with postsynaptic receptors can cause:
A _____________ in postsynaptic
membrane potential (_________ ~
closer to zero… depolarization)
Example: ___ ~ opens Na+
channels
An __________ in postsynaptic
membrane potential (_________ ~
further from
zero…hyperpolarized) Example:
________ ~ opens Cl- channels
Are action potentials always propagated
between cells?
Action potentials in pre-synaptic terminal don’t always
result in an action potential on the postsynaptic
membrane…
________ ___________
________ __________
Are action potentials always propagated
between cells?
Different action
potentials from
varying neurons
can
simultaneously
influence the
neuron they
collectively
synapse with to
create ________
___________
How are reflexes and pathways integrated?
___________
Reflexes and
Pathways
___________
___________
Can nervous tissue recover from injury?
Why would the
portion of an axon
severed from the
neuron cell body die?
If a nerve is cut, the ____ ______ and _____ _______ are
phagocytized. However, the Schwann cell bodies remain.
The proximal axon “________” for reconnection
If it encounters ________ _____ then it grows inside this
pathway to re-innervate the organ (muscle)
Why would this not readily occur in the CNS?