©JUSTTRACY EXAM SOLUTIONS
25/11/2024 1:25PM
BIO 669 Neuro I Revised Exam
Questions And Solutions
3 components of a neuron - answers✔✔cell body/soma, dendrites, axons
Densely packed cell bodies in the CNS are ______________. - answers✔✔nuclei
Densely packed cell bodies in the PNS are _____________. - answers✔✔ganglia
_______________ are the receiving part of the neuron. They receive incoming signals and
send signals to the neuron ____ ________. They eventually converge into the ___________
____________. - answers✔✔Dendrites, cell body, axon hillock
_____________ are able to be affected by external stimuli. - answers✔✔Dendrites
_________- take the signal to the end of the cell and carry impulses AWAY from the cell
body toward another neuron or effector. - answers✔✔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. -
answers✔✔axon hillock, excitatory graded potentials
As dendrites bring signals into the ___________ ____ _______ some may be
_____________-more likely to generate signal or ____________-prevent signal from being
developed. - answers✔✔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. - answers✔✔lowest, begin
During the __________ state, an imbalance of ions is created and maintained by ion pumps
and lack of permeability to ions. - answers✔✔resting state
, ©JUSTTRACY EXAM SOLUTIONS
25/11/2024 1:25PM
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 __________________. - answers✔✔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. - answers✔✔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? - answers✔✔negatively, positively
membrane, K & Na but mostly Na
Which way would K & Na move if left to diffusion and the membrane were permeable? -
answers✔✔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? - answers✔✔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. -
answers✔✔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 _______ - answers✔✔Electrical gradients-where opposite charges attract,
, ©JUSTTRACY EXAM SOLUTIONS
25/11/2024 1:25PM
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. - answers✔✔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. - answers✔✔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. - answers✔✔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? - answers✔✔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? - answers✔✔Probably
around -80mV
The closer an ion is to equilibrium potential, the more ____________ the membrane will be
to that ion. - answers✔✔permeable
25/11/2024 1:25PM
BIO 669 Neuro I Revised Exam
Questions And Solutions
3 components of a neuron - answers✔✔cell body/soma, dendrites, axons
Densely packed cell bodies in the CNS are ______________. - answers✔✔nuclei
Densely packed cell bodies in the PNS are _____________. - answers✔✔ganglia
_______________ are the receiving part of the neuron. They receive incoming signals and
send signals to the neuron ____ ________. They eventually converge into the ___________
____________. - answers✔✔Dendrites, cell body, axon hillock
_____________ are able to be affected by external stimuli. - answers✔✔Dendrites
_________- take the signal to the end of the cell and carry impulses AWAY from the cell
body toward another neuron or effector. - answers✔✔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. -
answers✔✔axon hillock, excitatory graded potentials
As dendrites bring signals into the ___________ ____ _______ some may be
_____________-more likely to generate signal or ____________-prevent signal from being
developed. - answers✔✔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. - answers✔✔lowest, begin
During the __________ state, an imbalance of ions is created and maintained by ion pumps
and lack of permeability to ions. - answers✔✔resting state
, ©JUSTTRACY EXAM SOLUTIONS
25/11/2024 1:25PM
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 __________________. - answers✔✔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. - answers✔✔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? - answers✔✔negatively, positively
membrane, K & Na but mostly Na
Which way would K & Na move if left to diffusion and the membrane were permeable? -
answers✔✔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? - answers✔✔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. -
answers✔✔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 _______ - answers✔✔Electrical gradients-where opposite charges attract,
, ©JUSTTRACY EXAM SOLUTIONS
25/11/2024 1:25PM
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. - answers✔✔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. - answers✔✔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. - answers✔✔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? - answers✔✔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? - answers✔✔Probably
around -80mV
The closer an ion is to equilibrium potential, the more ____________ the membrane will be
to that ion. - answers✔✔permeable
