PSIO 201 FINAL EXAM WITH PRECISE |! |! |! |! |! |!
DETAILED ANSWERS |!
neuronal tissue (two cell types): - Correct answer ✔a. nerve cells: neurons
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-involved in the generation and interpretation of 'electrical signals'
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b. glial cells: neuroglia
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-supports neuronal cell activity |! |! |!
resting membrane potential is the..... - Correct answer ✔baseline electrical
|! |! |! |! |! |! |! |! |! |!
condition of all cells |! |! |!
distribution of charges in resting membrane potential: - Correct answer
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✔extracellular fluid: equal number of + and - charges |! |! |! |! |! |! |! |!
plasma membrane: equal number of + and - charges
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cytosol: equal number of + and - charges
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resting membrane potential has what two parameters? - Correct answer ✔-
|! |! |! |! |! |! |! |! |! |!
transmembrane ion gradients (Na+ and K+) |! |! |! |! |!
-membrane permeability |!
transmembrane ion gradients: - Correct answer ✔-Na+ leaves the cell while |! |! |! |! |! |! |! |! |! |! |!
K+ is entering the cell
|! |! |! |!
,-ATPase allows this (ATPase develops and maintains steady-state ion
|! |! |! |! |! |! |! |! |!
gradients for ALL cells) |! |! |!
-K+ being pulled into the cell is an electrical force
|! |! |! |! |! |! |! |! |!
-K+ leak channels are present and allows K+ to leave the cell (chemical
|! |! |! |! |! |! |! |! |! |! |! |! |!
force)
-K+ leak channels are present in ALL cells
|! |! |! |! |! |! |!
membrane permeability: - Correct answer ✔-K+ leak channel
|! |! |! |! |! |! |!
-K+ from intracellular/cytoplasm is pushed out into the extracellular
|! |! |! |! |! |! |! |! |!
(chemical force) |!
-pumping creates ionic gradient for K+ |! |! |! |! |!
-K+ leaks out/down its concentration gradient which makes the inside of the
|! |! |! |! |! |! |! |! |! |! |! |!
cell more negative and the outside of the cell more positive
|! |! |! |! |! |! |! |! |! |!
-2 forces: (chemical force, push K+ out and electrical force, pull K+ in)
|! |! |! |! |! |! |! |! |! |! |! |!
in a typical cell (including neuronal cells): - Correct answer ✔-chemical and
|! |! |! |! |! |! |! |! |! |! |! |!
electrical forces for K+ are nearly in balance (results: inside-negative
|! |! |! |! |! |! |! |! |! |!
electrical potential) |!
the electrical potential difference is measured in: - Correct answer ✔volts
|! |! |! |! |! |! |! |! |! |!
(typical value: -0.05 volts to -0.1 volts)
|! |! |! |! |! |!
all cells at rest: - Correct answer ✔K+ is dominated and has an inside-
|! |! |! |! |! |! |! |! |! |! |! |! |!
negative membrane potential |! |!
, changes in membrane permeability can produce large changes in the..... -
|! |! |! |! |! |! |! |! |! |! |!
Correct answer ✔membrane potential |! |! |!
membrane permeability to an ion (K+ or Na+) = - Correct answer ✔opens
|! |! |! |! |! |! |! |! |! |! |! |! |!
channels for that ion |! |! |!
regulation of channel-mediated ion permeability allows cells to generate.... -
|! |! |! |! |! |! |! |! |! |!
Correct answer ✔electrical signals |! |! |!
keys to manipulation of membrane potential: - Correct answer ✔1. maintains
|! |! |! |! |! |! |! |! |! |! |!
stable Na+ and K+ gradients (Na/K because of ATPase)
|! |! |! |! |! |! |! |!
2. vary the activity of specific ion channels
|! |! |! |! |! |! |!
manipulation of membrane permeability: |! |! |!
-ion channels - Correct answer ✔-integral membrane proteins
|! |! |! |! |! |! |!
-channels can be open or closed (K+ leakage) |! |! |! |! |! |! |!
-some channels are routinely open
|! |! |! |!
-some channels have their open states regulated
|! |! |! |! |! |!
chemical (ligand) -gated channels: - Correct answer ✔-the ligand-gated
|! |! |! |! |! |! |! |! |!
channel opens when a signal molecule (ACh) binds to the channel protein
|! |! |! |! |! |! |! |! |! |! |! |!
-allows Ca2+, Na+, and K+ enter and leave the cell
|! |! |! |! |! |! |! |! |!
mechanically-gated channels: - Correct answer ✔-mechanically-gated channel |! |! |! |! |! |!
opens when the membrane gets stretched
|! |! |! |! |! |!
DETAILED ANSWERS |!
neuronal tissue (two cell types): - Correct answer ✔a. nerve cells: neurons
|! |! |! |! |! |! |! |! |! |! |!
-involved in the generation and interpretation of 'electrical signals'
|! |! |! |! |! |! |! |!
b. glial cells: neuroglia
|! |! |!
-supports neuronal cell activity |! |! |!
resting membrane potential is the..... - Correct answer ✔baseline electrical
|! |! |! |! |! |! |! |! |! |!
condition of all cells |! |! |!
distribution of charges in resting membrane potential: - Correct answer
|! |! |! |! |! |! |! |! |! |!
✔extracellular fluid: equal number of + and - charges |! |! |! |! |! |! |! |!
plasma membrane: equal number of + and - charges
|! |! |! |! |! |! |! |!
cytosol: equal number of + and - charges
|! |! |! |! |! |! |!
resting membrane potential has what two parameters? - Correct answer ✔-
|! |! |! |! |! |! |! |! |! |!
transmembrane ion gradients (Na+ and K+) |! |! |! |! |!
-membrane permeability |!
transmembrane ion gradients: - Correct answer ✔-Na+ leaves the cell while |! |! |! |! |! |! |! |! |! |! |!
K+ is entering the cell
|! |! |! |!
,-ATPase allows this (ATPase develops and maintains steady-state ion
|! |! |! |! |! |! |! |! |!
gradients for ALL cells) |! |! |!
-K+ being pulled into the cell is an electrical force
|! |! |! |! |! |! |! |! |!
-K+ leak channels are present and allows K+ to leave the cell (chemical
|! |! |! |! |! |! |! |! |! |! |! |! |!
force)
-K+ leak channels are present in ALL cells
|! |! |! |! |! |! |!
membrane permeability: - Correct answer ✔-K+ leak channel
|! |! |! |! |! |! |!
-K+ from intracellular/cytoplasm is pushed out into the extracellular
|! |! |! |! |! |! |! |! |!
(chemical force) |!
-pumping creates ionic gradient for K+ |! |! |! |! |!
-K+ leaks out/down its concentration gradient which makes the inside of the
|! |! |! |! |! |! |! |! |! |! |! |!
cell more negative and the outside of the cell more positive
|! |! |! |! |! |! |! |! |! |!
-2 forces: (chemical force, push K+ out and electrical force, pull K+ in)
|! |! |! |! |! |! |! |! |! |! |! |!
in a typical cell (including neuronal cells): - Correct answer ✔-chemical and
|! |! |! |! |! |! |! |! |! |! |! |!
electrical forces for K+ are nearly in balance (results: inside-negative
|! |! |! |! |! |! |! |! |! |!
electrical potential) |!
the electrical potential difference is measured in: - Correct answer ✔volts
|! |! |! |! |! |! |! |! |! |!
(typical value: -0.05 volts to -0.1 volts)
|! |! |! |! |! |!
all cells at rest: - Correct answer ✔K+ is dominated and has an inside-
|! |! |! |! |! |! |! |! |! |! |! |! |!
negative membrane potential |! |!
, changes in membrane permeability can produce large changes in the..... -
|! |! |! |! |! |! |! |! |! |! |!
Correct answer ✔membrane potential |! |! |!
membrane permeability to an ion (K+ or Na+) = - Correct answer ✔opens
|! |! |! |! |! |! |! |! |! |! |! |! |!
channels for that ion |! |! |!
regulation of channel-mediated ion permeability allows cells to generate.... -
|! |! |! |! |! |! |! |! |! |!
Correct answer ✔electrical signals |! |! |!
keys to manipulation of membrane potential: - Correct answer ✔1. maintains
|! |! |! |! |! |! |! |! |! |! |!
stable Na+ and K+ gradients (Na/K because of ATPase)
|! |! |! |! |! |! |! |!
2. vary the activity of specific ion channels
|! |! |! |! |! |! |!
manipulation of membrane permeability: |! |! |!
-ion channels - Correct answer ✔-integral membrane proteins
|! |! |! |! |! |! |!
-channels can be open or closed (K+ leakage) |! |! |! |! |! |! |!
-some channels are routinely open
|! |! |! |!
-some channels have their open states regulated
|! |! |! |! |! |!
chemical (ligand) -gated channels: - Correct answer ✔-the ligand-gated
|! |! |! |! |! |! |! |! |!
channel opens when a signal molecule (ACh) binds to the channel protein
|! |! |! |! |! |! |! |! |! |! |! |!
-allows Ca2+, Na+, and K+ enter and leave the cell
|! |! |! |! |! |! |! |! |!
mechanically-gated channels: - Correct answer ✔-mechanically-gated channel |! |! |! |! |! |!
opens when the membrane gets stretched
|! |! |! |! |! |!
