BIO 669 Neuro I Questions and verified
answers
As dendrites bring signals into the ___________ ____ _______ some may be _____________-more
likely to generate signal or ____________-prevent signal from being developed. ✔️✔️Correct Ans-
neuron cell body, excitatory, inhibitory
The initial segment of the axon is the area of the axon having the _________ threshold for
stimulation, so the AP ________ at this point. ✔️✔️Correct Ans-lowest, begin
During the __________ state, an imbalance of ions is created and maintained by ion pumps and lack
of permeability to ions. ✔️✔️Correct Ans-resting state
3 components of a neuron ✔️✔️Correct Ans-cell body/soma, dendrites, axons
Densely packed cell bodies in the CNS are ______________. ✔️✔️Correct Ans-nuclei
Densely packed cell bodies in the PNS are _____________. ✔️✔️Correct Ans-ganglia
_______________ are the receiving part of the neuron. They receive incoming signals and send
signals to the neuron ____ ________. They eventually converge into the ___________
____________. ✔️✔️Correct Ans-Dendrites, cell body, axon hillock
_____________ are able to be affected by external stimuli. ✔️✔️Correct Ans-Dendrites
_________- take the signal to the end of the cell and carry impulses AWAY from the cell body
toward another neuron or effector. ✔️✔️Correct Ans-axons
The ____________ ___________ is a cone-shape where the axon leaves the cell body. The axon
hillock determines whether there is enough ____________ ______________ _______________ to
develop and sustain an AP to send down the axon hillock. ✔️✔️Correct Ans-axon hillock, excitatory
graded potentials
,The concentration of ions are given in ___. The separation or _______________ of ions and charges
creates an ____________ _____________. Little to no difference in charges between inside and
outside __________________. ✔️✔️Correct Ans-mOsm,mM
polarization
electrical potential
depolarization
The __________ __________ refers to the inside of the cell, a -70mV -the charge associated with the
inside of the cell means that the inside aka the ____________ is more __________ than the
extracellular environment. ✔️✔️Correct Ans-membrane potential, cytoplasm, more negative
The inside of the cell is __________ charged and the outside of the cell is _____________ charged.
The different in charges is found at the ______________ not the cell as a whole. What ions cause this
difference? ✔️✔️Correct Ans-negatively, positively
membrane, K & Na but mostly Na
Which way would K & Na move if left to diffusion and the membrane were permeable? ✔️✔️Correct
Ans-High to low if left solely to diffusion.
IF there is 150 mM Na and 5mM K outside the cell and 15 mM Na and 150 mM K inside, why would
they not diffuse equally fast across the membrane? ✔️✔️Correct Ans-There are two forces acting on the
ions. Iff both Na & K were fully permeable, there would be a lot more Na move in than K move out
bc the 2nd thing to help drive these ions is the cell charges. Since the inside of the cell is negative, it
lends an additional force to move the Na in and retain K.
The _____________ ______________ is used to describe the forces affecting ion movement if
allowed to become permeable to a membrane. ___________ gradients move from high to low
concentration, thus becoming more ___________ aka a _________ energy state. ✔️✔️Correct Ans-
electrochemical gradient, Chemical, random, lower energy state
___________ gradients where opposite charges attract, similar charges repel which can set up a force
to move charged particles. ____________ are charges separated by a membrane and are measured in
_______ ✔️✔️Correct Ans-Electrical gradients-where opposite charges attract,
potentials
volts, mV
, _________ __________ __________ is the result of retained proteins within the cell and ions mostly
Na & K, creating ____________- gradients resulting in a relatively ________ charge within the inner
aspect of the plasma membrane. ✔️✔️Correct Ans-Resting membrane potential
electrochemical
negative
Na is _________ charged and attracted to a ______ environment inside the cell. It also has a high
____________ gradient helping to pull Na _____ as well. Both forces help to favor movement of Na
_______ the cell. ✔️✔️Correct Ans-Na is postitively charged, negative
concentration, in, into
How to tell whether the K will leave the cell or stay? Look at the _______________- gradient. In this
case, K is more likely to ______. It will continue to leave until the cell's inside is _________ enough
to pull back as many K ions in as are leaving, that will be K ____________ potential. ✔️✔️Correct
Ans-electrochemical gradient, leave, negative, equilibrium
_____________ ____________ a way to describe the voltage conditions necessary to counterbalance
the chemical gradient forces of a given _____________ ______ so that equilibrium is established. The
movement in=movement out for only that ______. I.E. What will it take voltage wise or __________
__________ to balance out the __________ __________ for that ion? ✔️✔️Correct Ans-Equilibrium
potential
single ion
ion
membrane potential, chemical diffusion
At what potential or membrane polarization does it require for K to be balanced in terms of the
concentration and electrical gradient OR what charge does the inside need to be negative to
counterbalance the outflow of K bc of the concentration gradient? ✔️✔️Correct Ans-Probably around -
80mV
The closer an ion is to equilibrium potential, the more ____________ the membrane will be to that
ion. ✔️✔️Correct Ans-permeable
Moving a membrane potential from -70mV to -50mV would be characterized as a ___________
event.
Not all depolarization lead to _________ __________. ✔️✔️Correct Ans-Depolarizing AP
answers
As dendrites bring signals into the ___________ ____ _______ some may be _____________-more
likely to generate signal or ____________-prevent signal from being developed. ✔️✔️Correct Ans-
neuron cell body, excitatory, inhibitory
The initial segment of the axon is the area of the axon having the _________ threshold for
stimulation, so the AP ________ at this point. ✔️✔️Correct Ans-lowest, begin
During the __________ state, an imbalance of ions is created and maintained by ion pumps and lack
of permeability to ions. ✔️✔️Correct Ans-resting state
3 components of a neuron ✔️✔️Correct Ans-cell body/soma, dendrites, axons
Densely packed cell bodies in the CNS are ______________. ✔️✔️Correct Ans-nuclei
Densely packed cell bodies in the PNS are _____________. ✔️✔️Correct Ans-ganglia
_______________ are the receiving part of the neuron. They receive incoming signals and send
signals to the neuron ____ ________. They eventually converge into the ___________
____________. ✔️✔️Correct Ans-Dendrites, cell body, axon hillock
_____________ are able to be affected by external stimuli. ✔️✔️Correct Ans-Dendrites
_________- take the signal to the end of the cell and carry impulses AWAY from the cell body
toward another neuron or effector. ✔️✔️Correct Ans-axons
The ____________ ___________ is a cone-shape where the axon leaves the cell body. The axon
hillock determines whether there is enough ____________ ______________ _______________ to
develop and sustain an AP to send down the axon hillock. ✔️✔️Correct Ans-axon hillock, excitatory
graded potentials
,The concentration of ions are given in ___. The separation or _______________ of ions and charges
creates an ____________ _____________. Little to no difference in charges between inside and
outside __________________. ✔️✔️Correct Ans-mOsm,mM
polarization
electrical potential
depolarization
The __________ __________ refers to the inside of the cell, a -70mV -the charge associated with the
inside of the cell means that the inside aka the ____________ is more __________ than the
extracellular environment. ✔️✔️Correct Ans-membrane potential, cytoplasm, more negative
The inside of the cell is __________ charged and the outside of the cell is _____________ charged.
The different in charges is found at the ______________ not the cell as a whole. What ions cause this
difference? ✔️✔️Correct Ans-negatively, positively
membrane, K & Na but mostly Na
Which way would K & Na move if left to diffusion and the membrane were permeable? ✔️✔️Correct
Ans-High to low if left solely to diffusion.
IF there is 150 mM Na and 5mM K outside the cell and 15 mM Na and 150 mM K inside, why would
they not diffuse equally fast across the membrane? ✔️✔️Correct Ans-There are two forces acting on the
ions. Iff both Na & K were fully permeable, there would be a lot more Na move in than K move out
bc the 2nd thing to help drive these ions is the cell charges. Since the inside of the cell is negative, it
lends an additional force to move the Na in and retain K.
The _____________ ______________ is used to describe the forces affecting ion movement if
allowed to become permeable to a membrane. ___________ gradients move from high to low
concentration, thus becoming more ___________ aka a _________ energy state. ✔️✔️Correct Ans-
electrochemical gradient, Chemical, random, lower energy state
___________ gradients where opposite charges attract, similar charges repel which can set up a force
to move charged particles. ____________ are charges separated by a membrane and are measured in
_______ ✔️✔️Correct Ans-Electrical gradients-where opposite charges attract,
potentials
volts, mV
, _________ __________ __________ is the result of retained proteins within the cell and ions mostly
Na & K, creating ____________- gradients resulting in a relatively ________ charge within the inner
aspect of the plasma membrane. ✔️✔️Correct Ans-Resting membrane potential
electrochemical
negative
Na is _________ charged and attracted to a ______ environment inside the cell. It also has a high
____________ gradient helping to pull Na _____ as well. Both forces help to favor movement of Na
_______ the cell. ✔️✔️Correct Ans-Na is postitively charged, negative
concentration, in, into
How to tell whether the K will leave the cell or stay? Look at the _______________- gradient. In this
case, K is more likely to ______. It will continue to leave until the cell's inside is _________ enough
to pull back as many K ions in as are leaving, that will be K ____________ potential. ✔️✔️Correct
Ans-electrochemical gradient, leave, negative, equilibrium
_____________ ____________ a way to describe the voltage conditions necessary to counterbalance
the chemical gradient forces of a given _____________ ______ so that equilibrium is established. The
movement in=movement out for only that ______. I.E. What will it take voltage wise or __________
__________ to balance out the __________ __________ for that ion? ✔️✔️Correct Ans-Equilibrium
potential
single ion
ion
membrane potential, chemical diffusion
At what potential or membrane polarization does it require for K to be balanced in terms of the
concentration and electrical gradient OR what charge does the inside need to be negative to
counterbalance the outflow of K bc of the concentration gradient? ✔️✔️Correct Ans-Probably around -
80mV
The closer an ion is to equilibrium potential, the more ____________ the membrane will be to that
ion. ✔️✔️Correct Ans-permeable
Moving a membrane potential from -70mV to -50mV would be characterized as a ___________
event.
Not all depolarization lead to _________ __________. ✔️✔️Correct Ans-Depolarizing AP
