Exam2 Flashcards
what is the three box model?
input (PNS)–>analysis/integration (CNS)–>output (PNS)
input
sensory afferent
“to carry forward”
PNS
analysis/integration
brain
spinal cord
CNS
output
motor efferent
“to carry away”
PNS
transduction
the conversion of 1 energy form to another
what are the three types of energy?
electromagnetic radiation–>(light–>vision)
mechanical(movement–>touch,hearing)
chemical (molecule –>taste, smell)
neuron
the functional unit of the nervous system
functional organization of a neuron
input-->dendrites
ligand gated channels
stretch activated
conductile-->axon
v-gated Na+ and K+ channels
output-->v-gated Ca2+ channelslaw of dynamic polarization
the information in the form of action potential will flow in one direction
cell body——->
axoplasmic transport
fast and slow
fast axoplasmic transport
get on an airplane and go directly somewhere vesicular proteins (neurotransmitters), kinesin, microtubules
slow axoplasmic transport
“move now and again”–>hitchhiker analogy
cytoplasmic (cytoskeleton), kinesin, microtubules, katanan
Glial cells in the CNS
astorcytes
oligondendrocytes
astrocytes
pick up ions and neurotransmitter
maintain the extracellular environment condosive to neuron
regulates the extracellular K+ concentration
regulates the neurotransmitter concentration at synapses
the output region releases a neurotransmitter into the synaptic cleft
basically bind neurotransmitters at the input site and vacuum them together
oligodendrocytes
-will myelinate many neurons
-insulating fat layer made out of cell membrane of the oligondendrocytes
-sends out a process that allows it to stick to the plasma membrane of the axon but it doesn’t stop, it then continues to send an extension around the cell
-the leading edge insinuated itself under the first layer then breaks the bonds between the two membranes
and then it will go around and around in circles and after a while it will go back around to the oligondendrocytes
-used to send out process to generate an insulating layer
-schwann cells do pretty much the same thing
multiple sclerosis
- reduced mylination disease of the glia cells
- disease of the oligodendrocytes
electrical movement through a membrane
chemical
electrical
chemical
ions –> ion goes down the concentration gradient /diffusion
electrical
negative charged impermeable things
“brake”
the membrane potential seeks…
the equilibrium potential for the ion that is most dominance (most permeable)
where are the K+ leak channels located
on the cell body (important for membrane resistance)
where are the stretch activated channels located
idkkk
where are the ligand gated channels located
on the dendrites
where are the v-gated Na+ channels located
in the nodes
where are the v-gated K+ channels located
in the nodal region
what are the 4 steps of the action potential
resting
depolarization
repolarization
hyperpolarization
at resting potential v-gated channels are…
all channels are closed
depolarization v-gated channels are…
Na+ channels are open
repolarization v-gated channels are…
Na+ channels inactivate
–>ball and chain
K+ channels are open
hyperpolarization v-gated channels are…
some K+ channels are open
Na+ channel resets
during resting ion permeability
K+ (due to the K+ leak)
depolarization ion permeability
Na+ flows into the cell
repolarization ion permeability
K+ flows out of the cell (down the concentration gradient)
hyperpolarization ion permeability
K+
resting action potential curve
flat
-70mv (around the Ek)
depolarization curve
sharp upward curve (approaching Ena=40)
repolarization curve
downward curve (approaching the Ek=-80)
hyperpolarization curve
below the resting potential (-70) to the -80mv=Ek
what is released from a lower motor neuron and binds to ligand gated channels found concentrated at the neuromuscular junction on the sarcolemma membrane
Acetylcholine Ach
an EPSP is generated in the muscle fiber and if threshold is met BLANK channels open which are located along BLANK
V-gated Na+
sarcolema
an action potential is generated in the muscle cell causing the BLANK plug to be removed from the BLANK located on the BLANK
DHP plug
RYR
sarcoplasmic reticulum
calcium is released into the sarcoplasm and binds to BLANK which causes BLANK to uncover myosin binding sites on actin filaments
trophonin C
tropomyosin
Actin and myosin bind when ATP is BLANK
hydrolyzed (cleaved)
The BLANK occurs when ADP + Pi leave
power stroke
For the muscle to relax, myosin and actin need to disassociate by BLANK binding to myosin
In addition BLANK needs to be pumped back into the BLANK
ATP
Ca2+
sarcoplasmic reticulum
what is the nervous system composed of
individual units called neurons
directionality of information flow
law of dynamic polarization
the neuron doctrine
the neuron as the fundamental structural unit of the nervous system
what did santiago say?
the nervous system was composed of individual units called neurons
directionality of information flow
law of dynamic polarization
where is protein synthesis confined to?
the neuronal cell body
what kind of channels are in the input region
ligand gated channels
the response is proportional to the number of channels that open
what kind of channels are in the conductile region
voltage gated channels (all or nothing)
Na+
K+
**action potential propogated along conductile region
**carried electrical information for long distances
neurons
assymmetric cells
axoplasmic transport
fast 200-400 m a day
vesillos and microtubules
slow -0.1-2mm a day
intermitten movement
what is a ganglian
a collection of nerve cell bodies that exists outside the central nervous system
threshold
the point where Na+ influx is balanced by K+ efflux
point where Na+ permeability is balanced by K+ permeability
membrane potential
seeks the equilibrium potential of the ion whose permeability is dominant
Ena
40mv
Ek
70-80mv
glial cells
act as glue–> cells holding the nervous system together
in the CNS glia are essential for regulating the environment in which neurons function
astrocytes
oligondendrocytes
mylination
they wrap conductile regions of neurons with concentric rings (layers) of plasma membrane that we call myelin (laid down in layers)
nerust potential
the equilibrium potential for potassium
sulcatory conduction
to hop
synapse
to clasp or to hold
