Veterinary Physiology - Nervous System
UPDATED ACTUAL Exam Questions and
CORRECT Answers
excitable tissue - CORRECT ANSWER - cells that are able to transmit electrical signals
down their cell membranes
voltage-gated channel - CORRECT ANSWER - opens in response to changes int he
membrane potential
K voltage-gated channels are - CORRECT ANSWER - a mixture of leakage channels that
are always open and closed channels that require an action potential to open
voltage-gated sodium channel - CORRECT ANSWER - 1. increased Na
2. increase in open Na channels
3. positive feedback loop starts
4. membrane potential rises to +30mV
5. inactive Na VG channels begin to close
voltage-gated K channel - CORRECT ANSWER - 1. increase in K leaving the cell
2. cell's [+] decrease
3. RMP restored
4. negative feedback loop
depolarization - CORRECT ANSWER - the loss of difference in charge across the plasma
membrane
steps to depolarization - CORRECT ANSWER - 1. Na permeability increases
2. Na moves into the cell
, 3. Cell [+] increases
4. depolarization
*increased Na permeability causes depolarization
repolarization - CORRECT ANSWER - the increase in charge difference across the plasma
membrane
steps to repolarization - CORRECT ANSWER - 1. K moves outside the cell
2. cell [-] increase
3. Na channels close
4. Na-K pump is simultaneously working to move Na and K
5. [K] increases
6. repolarization
absolute refractory period - CORRECT ANSWER - the time just after depolarization when
the axon is incapable of producing another action potential
relative refractory period - CORRECT ANSWER - repolarization is currently occurring; K
channels are still open; another action potential can occur, but it requires a stronger stimulus
All or None law - CORRECT ANSWER - if a stimulus exceeds the threshold potential, the
nerve or muscle fiber will give a response; if the threshold potential is not exceeded there will be
no response
excitability threshold - CORRECT ANSWER - how much the membrane potential must
rise to the get to the threshold potential
threshold potential - CORRECT ANSWER - the membrane potential that needs to be
acquired for an action potential to be initiated
UPDATED ACTUAL Exam Questions and
CORRECT Answers
excitable tissue - CORRECT ANSWER - cells that are able to transmit electrical signals
down their cell membranes
voltage-gated channel - CORRECT ANSWER - opens in response to changes int he
membrane potential
K voltage-gated channels are - CORRECT ANSWER - a mixture of leakage channels that
are always open and closed channels that require an action potential to open
voltage-gated sodium channel - CORRECT ANSWER - 1. increased Na
2. increase in open Na channels
3. positive feedback loop starts
4. membrane potential rises to +30mV
5. inactive Na VG channels begin to close
voltage-gated K channel - CORRECT ANSWER - 1. increase in K leaving the cell
2. cell's [+] decrease
3. RMP restored
4. negative feedback loop
depolarization - CORRECT ANSWER - the loss of difference in charge across the plasma
membrane
steps to depolarization - CORRECT ANSWER - 1. Na permeability increases
2. Na moves into the cell
, 3. Cell [+] increases
4. depolarization
*increased Na permeability causes depolarization
repolarization - CORRECT ANSWER - the increase in charge difference across the plasma
membrane
steps to repolarization - CORRECT ANSWER - 1. K moves outside the cell
2. cell [-] increase
3. Na channels close
4. Na-K pump is simultaneously working to move Na and K
5. [K] increases
6. repolarization
absolute refractory period - CORRECT ANSWER - the time just after depolarization when
the axon is incapable of producing another action potential
relative refractory period - CORRECT ANSWER - repolarization is currently occurring; K
channels are still open; another action potential can occur, but it requires a stronger stimulus
All or None law - CORRECT ANSWER - if a stimulus exceeds the threshold potential, the
nerve or muscle fiber will give a response; if the threshold potential is not exceeded there will be
no response
excitability threshold - CORRECT ANSWER - how much the membrane potential must
rise to the get to the threshold potential
threshold potential - CORRECT ANSWER - the membrane potential that needs to be
acquired for an action potential to be initiated
