Understanding Patho Quiz 2 Neurological System Exam 1 Questions Answered Correctly Graded A+
What are the 3 components of the neuron? - Answers cell body (soma), dendrites, axons
where is the cell body (soma) located? - Answers mainly in the CNS
Densely packed cell bodies in the CNS are?
PNS? - Answers nuclei.
ganglia.
What is located in the cell body (soma)? - Answers nucleus and cytoplasm.
Dendrites are the ________ portion of the neuron. - Answers Receptive portion.
They accept and sense external stimuli. Stimulate incoming signals to cell body.
Axons transmit impulses where? - Answers Transmit impulses AWAY from cell body of neuron.
the long thread like part of a nerve cell along which impulses are conducted from the cell body to other
cells.
what is the cone-shaped process where the axon leaves the cell body? - Answers axon hillock
As dendrites bring signals to the axon hillock, what occurs? - Answers the inhibitory and exhibitory
graded potentials are summed to determine if an action potential can occur to send a signal down the
axon hillock.
What part of the axon has the lowest threshold for stimulation?
and what occurs here? - Answers The initial segment of the axon.
the action potentials begin at this point.
Describe membrane polarization during a neuron's resting state. - Answers imbalance of ions is created
and maintained by ion pumps.
,The membrane lacks permeability to ions.
unit of measurement of ion concentration - Answers mM (mOsm)
the separation or ______________ of ions and charges creates _____________. - Answers polarization;
an electrical potential.
the further distance between the charges = - Answers the more polarized .
Therefore, the closer the distance between the ends results in: - Answers depolarization
The membrane potential refers to the _______________ of the cell. - Answers inside
If the membrane potential is -70 mV, this means: - Answers that the inside (cytoplasm) is more negative
than the extracellular environment.
The difference in potential is found where on the cell? - Answers at the membrane.
NOT the cell as a whole.
what ions cause the difference in potential found at the membrane? - Answers mostly Na+, but K+ too.
Which way would K+ move if left to diffusion and the membrane where permeable?
Na+? - Answers Move from high to low concentration. So K+ would move to ECF and Na+ to the ICF.
If there is 150mM Na+ and 5mM K+ outside the cell and 15mM Na+ and 150mM K+ inside, why would
they not diffuse equally fast across the membrane? - Answers If fully permeable, many more Na+ would
move into the cell than K+ out d/t negative charge and lower concentration of Na+ inside the cell.
Na+ has an electrical and chemical gradient that is driving Na+ into the ICF.
The positive Na+ will be highly attracted to the negative ICF. Additional force to pull Na+ in and retain
K+.
what is used to describe the forces affecting ion movement if allowed to become permeable to a
membrane? - Answers electrochemical gradient.
Chemical gradients move from __________ concentration to __________.
,This makes them become: - Answers high concentration to low conentration.
becomes more random -- lower energy state.
How to electrical gradients operate? - Answers opposite charges attract, similar charges repel.
This can set up a force to move charged particles.
Potentials are charges that are separated by:
They are measured in: - Answers a membrane.
volts or millivolts (mV)
Resting membrane potential is the result of: - Answers retained proteins within the cell and ions (mostly
Na+ and K+) creating electrochemical gradients.
This results in a relatively negative charge within the inner aspect of the plasma membrane.
Why does K+ not move as freely as Na+ with a fully permeable membrane? - Answers K+ has a chemical
gradient that favors its outflux into the ECF.
However, an electrical gradient is present inside the cell that favors K+ to remain inside the cell.
What is an equilibrium potential? - Answers a way to describe the voltage conditions necessary to
counterbalance the chemical gradient forces of a given single ion so that equilibrium is established for
that ion alone.
movement in = movement out.
, example: what will it take voltage-wise (membrane potential) to balance out chemical diffusion for that
ion.
compare the equilibrium potentials between K+, Na+, Ca2+ and Cl-. - Answers Na+ and Ca2+ have
positive equilibrium potentials.
K+ and Cl- have negative ones.
Moving a membrane potential from -70mV to -50mV would be characterized as a _______ polarizing
event. - Answers depolarizing.
true/false:
all depolarizations lead to action potentials. - Answers FALSE.
not all depolarizations lead to action potentials.
action potential vs graded potential - Answers action potentials have self-sustaining movements that are
similar, and sustain movements of signals down a membrane.
graded potentials are local, brief changes in membrane potentials that decrease over distance. They
cause depolarization or hyperpolarization, but do not trigger a movement of signals. (magniture varies).
An action potentials starts if a membrane is: - Answers depolarized enough to trigger voltage-gated ion
channels.
Na+ will cause this depolarization/voltage.
What is the term for the minimum depolarization needed to form an action potential? - Answers
threshold.
How are action potentials self-sustaining? - Answers when a voltage-gate opens, this further increases
Na+ influx and highly depolarizes the cell.
This can cause the neighboring voltage-gated channels to open and send a cascade of responses down
the membrane like dominos.
What are the 3 components of the neuron? - Answers cell body (soma), dendrites, axons
where is the cell body (soma) located? - Answers mainly in the CNS
Densely packed cell bodies in the CNS are?
PNS? - Answers nuclei.
ganglia.
What is located in the cell body (soma)? - Answers nucleus and cytoplasm.
Dendrites are the ________ portion of the neuron. - Answers Receptive portion.
They accept and sense external stimuli. Stimulate incoming signals to cell body.
Axons transmit impulses where? - Answers Transmit impulses AWAY from cell body of neuron.
the long thread like part of a nerve cell along which impulses are conducted from the cell body to other
cells.
what is the cone-shaped process where the axon leaves the cell body? - Answers axon hillock
As dendrites bring signals to the axon hillock, what occurs? - Answers the inhibitory and exhibitory
graded potentials are summed to determine if an action potential can occur to send a signal down the
axon hillock.
What part of the axon has the lowest threshold for stimulation?
and what occurs here? - Answers The initial segment of the axon.
the action potentials begin at this point.
Describe membrane polarization during a neuron's resting state. - Answers imbalance of ions is created
and maintained by ion pumps.
,The membrane lacks permeability to ions.
unit of measurement of ion concentration - Answers mM (mOsm)
the separation or ______________ of ions and charges creates _____________. - Answers polarization;
an electrical potential.
the further distance between the charges = - Answers the more polarized .
Therefore, the closer the distance between the ends results in: - Answers depolarization
The membrane potential refers to the _______________ of the cell. - Answers inside
If the membrane potential is -70 mV, this means: - Answers that the inside (cytoplasm) is more negative
than the extracellular environment.
The difference in potential is found where on the cell? - Answers at the membrane.
NOT the cell as a whole.
what ions cause the difference in potential found at the membrane? - Answers mostly Na+, but K+ too.
Which way would K+ move if left to diffusion and the membrane where permeable?
Na+? - Answers Move from high to low concentration. So K+ would move to ECF and Na+ to the ICF.
If there is 150mM Na+ and 5mM K+ outside the cell and 15mM Na+ and 150mM K+ inside, why would
they not diffuse equally fast across the membrane? - Answers If fully permeable, many more Na+ would
move into the cell than K+ out d/t negative charge and lower concentration of Na+ inside the cell.
Na+ has an electrical and chemical gradient that is driving Na+ into the ICF.
The positive Na+ will be highly attracted to the negative ICF. Additional force to pull Na+ in and retain
K+.
what is used to describe the forces affecting ion movement if allowed to become permeable to a
membrane? - Answers electrochemical gradient.
Chemical gradients move from __________ concentration to __________.
,This makes them become: - Answers high concentration to low conentration.
becomes more random -- lower energy state.
How to electrical gradients operate? - Answers opposite charges attract, similar charges repel.
This can set up a force to move charged particles.
Potentials are charges that are separated by:
They are measured in: - Answers a membrane.
volts or millivolts (mV)
Resting membrane potential is the result of: - Answers retained proteins within the cell and ions (mostly
Na+ and K+) creating electrochemical gradients.
This results in a relatively negative charge within the inner aspect of the plasma membrane.
Why does K+ not move as freely as Na+ with a fully permeable membrane? - Answers K+ has a chemical
gradient that favors its outflux into the ECF.
However, an electrical gradient is present inside the cell that favors K+ to remain inside the cell.
What is an equilibrium potential? - Answers a way to describe the voltage conditions necessary to
counterbalance the chemical gradient forces of a given single ion so that equilibrium is established for
that ion alone.
movement in = movement out.
, example: what will it take voltage-wise (membrane potential) to balance out chemical diffusion for that
ion.
compare the equilibrium potentials between K+, Na+, Ca2+ and Cl-. - Answers Na+ and Ca2+ have
positive equilibrium potentials.
K+ and Cl- have negative ones.
Moving a membrane potential from -70mV to -50mV would be characterized as a _______ polarizing
event. - Answers depolarizing.
true/false:
all depolarizations lead to action potentials. - Answers FALSE.
not all depolarizations lead to action potentials.
action potential vs graded potential - Answers action potentials have self-sustaining movements that are
similar, and sustain movements of signals down a membrane.
graded potentials are local, brief changes in membrane potentials that decrease over distance. They
cause depolarization or hyperpolarization, but do not trigger a movement of signals. (magniture varies).
An action potentials starts if a membrane is: - Answers depolarized enough to trigger voltage-gated ion
channels.
Na+ will cause this depolarization/voltage.
What is the term for the minimum depolarization needed to form an action potential? - Answers
threshold.
How are action potentials self-sustaining? - Answers when a voltage-gate opens, this further increases
Na+ influx and highly depolarizes the cell.
This can cause the neighboring voltage-gated channels to open and send a cascade of responses down
the membrane like dominos.
