Passive Membrane Properties Flashcards
Neurons produce a non-propagated local potential called a(n) _____, due to a local change in _____.
electrotonic potential
ionic conductance
(e.g. channel opening due to synaptic response).
When a electrotonic potential spreads along a stretch of membrane, it becomes _____.
exponentially smaller
Electrotonic refers to the “_____” spread of charge inside a neuron.
passive
“Passive” means that voltage-dependent changes in membrane conductance do not contribute.
Neurons produce a propagated impulse called a(n) _____.
action potential
The electrotonic potential travels via _____.
electrotonic spread
Electrotonic potentials from multiple sources can sum _____ or _____.
spatially
temporally
electrotonic spread is a(n) _____ response.
graded
Electrotonic spread and summation of many inputs is responsible for increasing the _____ of the soma to _____ and trigger the_____.
voltage
exceed threshold
action potential
Electrotonic potentials are conducted _____ than
action potentials, but _____ rapidly, thus they are unsuitable for _____.
faster
attenuate
long-distance signaling
The action potential is a(n) _____ propagation down the _____ of the neuron during which the current is _____.
all-or-none
axon
regenerated
Input resistance _____ in outward or inward current pulses and produces _____ and _____
changes in membrane potential.
increases
proportional
symmetrical
An I-V curve is obtained by plotting the _____ against the _____.
steady state voltage
injected current
The slope of the I-V curve defines the _____ of the neuron.
input resistance
The input resistance of the cell determines how much the cell will _____ in response
to a steady current.
depolarize
The magnitude of a cell’s depolarization is given by _____.
Voltage is equal to the product of _____ and _____.
Ohm’s law
V = I * R
current
resistance
In a neuron, the input resistance depends on both the _____ and the _____.
density of the resting ion channels in the membrane
(i.e. the number of open channels per unit area of membrane)
size of the cell
The larger the neuron, the _____ its
membrane surface area will be and the _____ the input resistance.
greater
lower
(since there will be more
resting channels to conduct ions)
capacitance (unit = _____) is the ability
of a body to _____.
farad
hold an electrical charge
a capacitor is a device that stores energy in the _____ created between _____ on which _____ electric charges have been placed.
electric field
a pair of conductors
equal but opposite
A capacitor consists of two _____ separated by a(n) _____.
conductors (plates)
insulator (dielectric)
In a parallel plate capacitor, capacitance is directly proportional to _____ and inversely proportional to _____.
the surface area of the conductor plates
the separation distance between the plates
C = Q / V
The action potential is a regenerative wave of _____.
Na+ permeability increase
The length constant (_____) is a measure of the efficiency of the passive spread of _____ along the _____.
lambda
voltage changes
membrane (axon or dendrite)
