Question 1

During the so called depolarization block the voltage-gated Na+ channels are in their 
 "closed and not capable" of opening configuration.

Accepted Answer

A) True 
 B)False

Question 2

During the initial, depolarizing phase of the action potential, the voltage-gated Na+-channel is in which conformation?

Accepted Answer

A)  closed but capable of opening 
B)  open, or activated 
C)  closed and not capable of opening 
D)  activation gate open; inactivation gate closed 
E)  activation gate closed; inactivation gate closed 
A)  closed but capable of opening 
B)  open, or activated 
C)  closed and not capable of opening 
D)  activation gate open; inactivation gate closed 
E)  activation gate closed; inactivation gate closed

Question 3

Action potentials are normally initiated at the axon hillock because

Accepted Answer

A)  there is a particularly high density of voltage-gated sodium channels there. 
B)  threshold potential is lower there than at other sites along the plasma membrane. 
C)  activation of sodium channels at the axon hillock results in a particularly strong inward current and consequent depolarization. 
D)  all of these. 
E)  none of these. 
A)  there is a particularly high density of voltage-gated sodium channels there. 
B)  threshold potential is lower there than at other sites along the plasma membrane. 
C)  activation of sodium channels at the axon hillock results in a particularly strong inward current and consequent depolarization. 
D)  all of these. 
E)  none of these.

Question 4

In cells where the equilibrium potential for Cl- equals the resting potential, opening Cl- channels in the subsynaptic membrane

Accepted Answer

A)  has no effect on the probability of the postsynaptic cell reaching threshold since there's no movement of Cl-. 
B)  increases the probability of the postsynaptic cell reaching threshold since the entry of Na+ into the cell (through another route) will make the cell less negative and allow Cl- to leave the cell, offsetting the effect of Na+. 
C)  decreases the probability of the postsynaptic cell reaching threshold since the entry of Na+ into the cell (through another route) will make the cell less negative and Cl- will enter the cell, offsetting the depolarizing effect of Na+. 
D)  none of these. 
A)  has no effect on the probability of the postsynaptic cell reaching threshold since there's no movement of Cl-. 
B)  increases the probability of the postsynaptic cell reaching threshold since the entry of Na+ into the cell (through another route) will make the cell less negative and allow Cl- to leave the cell, offsetting the effect of Na+. 
C)  decreases the probability of the postsynaptic cell reaching threshold since the entry of Na+ into the cell (through another route) will make the cell less negative and Cl- will enter the cell, offsetting the depolarizing effect of Na+. 
D)  none of these.

Question 5

Action potentials are transmitted unperturbed across electrical synapses.

Accepted Answer

A) True 
 B)False

Question 6

At a neuromuscular synapse receptors of the cholinergic type bind acetylcholine.

Accepted Answer

A) True 
 B)False

Question 7

Threshold potential is

Accepted Answer

A)  typically between -50 mV and -55 mV. 
B)  typically 10 mV to 15 mV higher than resting potential. 
C)  the membrane potential at which a graded potential is converted to an action potential. 
D)  all of these. 
E)  none of these. 
A)  typically between -50 mV and -55 mV. 
B)  typically 10 mV to 15 mV higher than resting potential. 
C)  the membrane potential at which a graded potential is converted to an action potential. 
D)  all of these. 
E)  none of these.

Question 8

When a single synaptic input fires repeatedly, generating a cumulative effect on the postsynaptic membrane potential, that phenomenon is known as summation.

Accepted Answer

A)  temporary 
B)  temporal 
C)  lateral 
D)  spatial 
E)  grand 
A)  temporary 
B)  temporal 
C)  lateral 
D)  spatial 
E)  grand

Question 9

Match each sentence with the most appropriate choice:
-Synaptic vesicle

Accepted Answer

A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency 
A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency

Question 10

Distinguish between excitatory and inhibitory postsynaptic events. Your answer should include a definition of each and an explanation of the ion currents associated with each.

Accepted Answer

Excitatory and inhibitory postsynaptic e

Question 11

During the absolute refractory period for a neuron, most voltage-gated Na+-channels are in which conformation?

Accepted Answer

A)  closed but capable of opening 
B)  open, or activated 
C)  closed and not capable of opening 
D)  Any of these. 
E)  None of these. 
A)  closed but capable of opening 
B)  open, or activated 
C)  closed and not capable of opening 
D)  Any of these. 
E)  None of these.

Question 12

Tetraethylammonium (TEA) is one compound that is used to block Na+ channels.

Accepted Answer

A) True 
 B)False

Question 13

Based on the urgency of the information they convey, would you expect pain fibers to be myelinated or unmyelinated, large in diameter or small in diameter? Justify your answer.

Accepted Answer

Pain fibers are expected to be unmyelina

Question 14

Match each sentence with the most appropriate choice:
-Neurotransmitter receptor

Accepted Answer

A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency 
A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency

Question 15

When compared to normal resting conditions, a neuron will become hyperpolarized

Accepted Answer

A)  when there is an increase in transmembrane potential. 
B)  if positive ions such as Ca2+ ions leak into the neuron. 
C)  if there is a decrease in number of intracellular potassium ions. 
D)  if positive ions such as Ca2+ ions leak into the neuron or when there is an increase in transmembrane potential. 
E)  if there is a decrease in number of intracellular potassium ions or when there is an increase in transmembrane potential . 
A)  when there is an increase in transmembrane potential. 
B)  if positive ions such as Ca2+ ions leak into the neuron. 
C)  if there is a decrease in number of intracellular potassium ions. 
D)  if positive ions such as Ca2+ ions leak into the neuron or when there is an increase in transmembrane potential. 
E)  if there is a decrease in number of intracellular potassium ions or when there is an increase in transmembrane potential .

Question 16

Retrograde signaling occurs when

Accepted Answer

A)  receptors on the presynaptic membrane are activated resulting in a depolarization of the presynaptic dendrites. 
B)  acetylcholinesterase levels in a synapse are too high . 
C)  a postsynaptic cell secretes a signaling molecule that influences the sensitivity of the presynaptic terminal. 
D)  enzymes responsible for the breakdown of the neurotransmitter at a synapse are not produced in sufficient quantity. 
E)  none of these. 
A)  receptors on the presynaptic membrane are activated resulting in a depolarization of the presynaptic dendrites. 
B)  acetylcholinesterase levels in a synapse are too high . 
C)  a postsynaptic cell secretes a signaling molecule that influences the sensitivity of the presynaptic terminal. 
D)  enzymes responsible for the breakdown of the neurotransmitter at a synapse are not produced in sufficient quantity. 
E)  none of these.

Question 17

Which of the following statements about giant axons is NOT true?

Accepted Answer

A)  They can be found in annelids and cockroaches. 
B)  They can be unicellular. 
C)  They are involved in the coordination of abrupt movements. 
D)  They were first identified and studied in squid. 
E)  They may arise as the result of fusion of smaller fibers. 
A)  They can be found in annelids and cockroaches. 
B)  They can be unicellular. 
C)  They are involved in the coordination of abrupt movements. 
D)  They were first identified and studied in squid. 
E)  They may arise as the result of fusion of smaller fibers.

Question 18

Match each sentence with the most appropriate choice:
-Myelination

Accepted Answer

A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency 
A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency

Question 19

Neurotransmitters are

Accepted Answer

A)  chemical messengers used at chemical synapses. 
B)  found in synaptic vesicles in the synaptic knob. 
C)  released in response to elevated calcium in the axon terminal. 
D)  able to bind to receptors on the post-synaptic cell. 
E)  All of these. 
A)  chemical messengers used at chemical synapses. 
B)  found in synaptic vesicles in the synaptic knob. 
C)  released in response to elevated calcium in the axon terminal. 
D)  able to bind to receptors on the post-synaptic cell. 
E)  All of these.

Question 20

Match each sentence with the most appropriate choice:
-Electrical synapse

Accepted Answer

A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency 
A)  Calcium 
B)  Postsynaptic neuron 
C)  Gap junction 
D)  Dense-core vesicles 
E)  All-or-none
F) Reduced membrane potential
G) Increased membrane potential
H) Decremental
I) Salutatory conduction
J) Action potential frequency

During the so called depolarization block the voltage-gated Na+ channels are in their "closed and not capable" of opening configuration.

During the initial, depolarizing phase of the action potential, the voltage-gated Na⁺-channel is in which conformation?

Action potentials are normally initiated at the axon hillock because

In cells where the equilibrium potential for Cl^- equals the resting potential, opening Cl^- channels in the subsynaptic membrane

Action potentials are transmitted unperturbed across electrical synapses.

At a neuromuscular synapse receptors of the cholinergic type bind acetylcholine.

Threshold potential is

When a single synaptic input fires repeatedly, generating a cumulative effect on the postsynaptic membrane potential, that phenomenon is known as summation.

Match each sentence with the most appropriate choice: -Synaptic vesicle

Distinguish between excitatory and inhibitory postsynaptic events. Your answer should include a definition of each and an explanation of the ion currents associated with each.

During the absolute refractory period for a neuron, most voltage-gated Na⁺-channels are in which conformation?

Tetraethylammonium (TEA) is one compound that is used to block Na⁺ channels.

Based on the urgency of the information they convey, would you expect pain fibers to be myelinated or unmyelinated, large in diameter or small in diameter? Justify your answer.

Match each sentence with the most appropriate choice: -Neurotransmitter receptor

When compared to normal resting conditions, a neuron will become hyperpolarized

Retrograde signaling occurs when

Which of the following statements about giant axons is NOT true?

Match each sentence with the most appropriate choice: -Myelination

Neurotransmitters are

Match each sentence with the most appropriate choice: -Electrical synapse

Homeostasis and Integration: The Foundations of Physiology

Cellular and Molecular Physiology

Membrane Physiology

Nervous Systems

Sensory Physiology

Endocrine Systems

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Defense Systems

Respiratory Systems

Excretory Systems

Fluid and Acid-Base Balance

Digestive Systems

Energy Balance and Thermal Physiology

Reproductive Systems

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Exam 4: Neuronal Physiology

During the so called depolarization block the voltage-gated Na+ channels are in their "closed and not capable" of opening configuration.

During the initial, depolarizing phase of the action potential, the voltage-gated Na+-channel is in which conformation?

Action potentials are normally initiated at the axon hillock because

In cells where the equilibrium potential for Cl- equals the resting potential, opening Cl- channels in the subsynaptic membrane

Action potentials are transmitted unperturbed across electrical synapses.

At a neuromuscular synapse receptors of the cholinergic type bind acetylcholine.

Threshold potential is

When a single synaptic input fires repeatedly, generating a cumulative effect on the postsynaptic membrane potential, that phenomenon is known as summation.

Match each sentence with the most appropriate choice: -Synaptic vesicle

Distinguish between excitatory and inhibitory postsynaptic events. Your answer should include a definition of each and an explanation of the ion currents associated with each.

During the absolute refractory period for a neuron, most voltage-gated Na+-channels are in which conformation?

Tetraethylammonium (TEA) is one compound that is used to block Na+ channels.

Based on the urgency of the information they convey, would you expect pain fibers to be myelinated or unmyelinated, large in diameter or small in diameter? Justify your answer.

Match each sentence with the most appropriate choice: -Neurotransmitter receptor

When compared to normal resting conditions, a neuron will become hyperpolarized

Retrograde signaling occurs when

Which of the following statements about giant axons is NOT true?

Match each sentence with the most appropriate choice: -Myelination

Neurotransmitters are

Match each sentence with the most appropriate choice: -Electrical synapse

Homeostasis and Integration: The Foundations of Physiology

Cellular and Molecular Physiology

Membrane Physiology

Nervous Systems

Sensory Physiology

Endocrine Systems

Muscle Physiology

Circulatory Systems

Defense Systems

Respiratory Systems

Excretory Systems

Fluid and Acid-Base Balance

Digestive Systems

Energy Balance and Thermal Physiology

Reproductive Systems

Filters

During the initial, depolarizing phase of the action potential, the voltage-gated Na⁺-channel is in which conformation?

In cells where the equilibrium potential for Cl^- equals the resting potential, opening Cl^- channels in the subsynaptic membrane

During the absolute refractory period for a neuron, most voltage-gated Na⁺-channels are in which conformation?

Tetraethylammonium (TEA) is one compound that is used to block Na⁺ channels.