Question 1

When comparing action potentials to graded potentials,an/two important distinguishing characteristic/s is/are

Accepted Answer

A)  graded potentials can undergo summation. 
B)  action potentials can undergo summation. 
C)  that the rate of action potentials is limited by the refractory period. 
D)  graded potentials can undergo summation and the rate of action potentials is limited by the refractory period. 
E)  action potentials can undergo summation and the rate of action potentials is limited by the refractory period. 
A)  graded potentials can undergo summation. 
B)  action potentials can undergo summation. 
C)  that the rate of action potentials is limited by the refractory period. 
D)  graded potentials can undergo summation and the rate of action potentials is limited by the refractory period. 
E)  action potentials can undergo summation and the rate of action potentials is limited by the refractory period.

Question 2

Caffeine,nicotine,and alcohol all have effects on

Accepted Answer

A)  action potential conduction. 
B)  long-term potentiation. 
C)  synaptic activity. 
D)  neurotransmitter degradation. 
E)  neurotransmitter reuptake. 
A)  action potential conduction. 
B)  long-term potentiation. 
C)  synaptic activity. 
D)  neurotransmitter degradation. 
E)  neurotransmitter reuptake.

Question 3

Compare and contrast action and graded potentials.Your answer should include a definition of each,types,characteristics,ionic basis,functions,and anything else necessary to answer the question.

Accepted Answer

Action potentials are stereotyped change

Question 4

A compound action potential is recorded using electrodes on a nerve.How does a nerve differ from an axon? Amplitude and duration of a compound action potential vary according to the stimulus intensity applied to the nerve.Given that there is no such variation in the action potential of a single axon,how can you explain this?

Accepted Answer

A nerve consists of many axons.A regular

Question 5

Match the term with its description (answers may be used more than once).
-receive(s)most of the incoming synapses

Accepted Answer

A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia 
A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia

Question 6

If potassium channels in a neuron were blocked,would it be possible to produce an action potential? If so,describe the probable appearance of these components of a graph: threshold,rising phase,peak,falling phase,undershoot.If not,explain.

Accepted Answer

Assuming sodium channels are functioning

Question 7

Spatial summation refers to

Accepted Answer

A)  electrical signals reaching neurons from outer space. 
B)  multiple graded potentials arriving at one location simultaneously. 
C)  repeated graded potentials reaching the trigger zone one after the other. 
D)  suprathreshold potentials triggering action potentials that are extra large. 
E)  All of the answers are correct. 
A)  electrical signals reaching neurons from outer space. 
B)  multiple graded potentials arriving at one location simultaneously. 
C)  repeated graded potentials reaching the trigger zone one after the other. 
D)  suprathreshold potentials triggering action potentials that are extra large. 
E)  All of the answers are correct.

Question 8

Multiple sclerosis (MS)is one of the better known diseases resulting from demyelination of axons (in MS,only CNS axons are affected).Some of the earliest symptoms of the disease are difficulty in focusing the eyes,such as in reading,and difficulty in maintaining balance,and frequently not being able to make adjustments in posture to avoid falling.How do these symptoms "fit" with what you know about nerve impulses,myelin sheaths,and the location of gated ion channels in the membranes of axons?

Accepted Answer

Symptoms listed all involve loss of moto

Question 9

Compare and contrast the communication mechanisms between the nervous and endocrine systems.In other words,how do neurons and neurotransmitters signal to their postsynaptic cells,compared to the way endocrine glands and hormones communicate with their target cells?

Accepted Answer

(Note to instructor: Students must have

Question 10

Why are mitochondria necessary at axon terminals?

Accepted Answer

Energy is required i

Question 11

The multiple thin,branched structures on a neuron whose main function is to receive incoming signals are the

Accepted Answer

A)  cell bodies. 
B)  axons. 
C)  dendrites. 
D)  somata. 
E)  None of the answers are correct. 
A)  cell bodies. 
B)  axons. 
C)  dendrites. 
D)  somata. 
E)  None of the answers are correct.

Question 12

Conduction occurs along an axon because

Accepted Answer

A)  outflow of K+ triggers the adjacent channels to open. 
B)  inflow of Na+ triggers the adjacent channels to open. 
C)  once Na+ enters the cell, the entire membrane depolarizes simultaneously. 
D)  axonal transport "walks" voltage changes along the membrane. 
A)  outflow of K+ triggers the adjacent channels to open. 
B)  inflow of Na+ triggers the adjacent channels to open. 
C)  once Na+ enters the cell, the entire membrane depolarizes simultaneously. 
D)  axonal transport "walks" voltage changes along the membrane.

Question 13

Polio is an uncommon disease in most developed countries,but prior to widespread use of the polio vaccine,it was very common.Polio is caused by a virus that infects somatic motor neurons and destroys them.From this information,would you expect a polio victim to lose sensation,motor control,other organ function,and/or cognitive function? Explain.While most victims of polio survive,some do not.What is the most likely cause of death?

Accepted Answer

If only motor neurons are affe

Question 14

The total amount of neurotransmitter released at the axon terminal is directly related to

Accepted Answer

A)  the amplitude of the action potential. 
B)  the length of the axon. 
C)  the total number of action potentials. 
D)  the amplitude of the graded potential. 
A)  the amplitude of the action potential. 
B)  the length of the axon. 
C)  the total number of action potentials. 
D)  the amplitude of the graded potential.

Question 15

If a stimulating electrode is placed in the middle of a resting axon and an above-threshold voltage is applied to the electrode action potentials

Accepted Answer

A)  will not occur. 
B)  will start at that point and proceed only toward the axon terminal. 
C)  will start at that point and proceed only toward the cell body. 
D)  will start at that point and travel in both directions in the axon. 
A)  will not occur. 
B)  will start at that point and proceed only toward the axon terminal. 
C)  will start at that point and proceed only toward the cell body. 
D)  will start at that point and travel in both directions in the axon.

Question 16

How would blocking retrograde transport in an axon affect the activity of a neuron?

Accepted Answer

A)  The neuron would not be able to produce neurotransmitters. 
B)  The neuron would not be able to produce action potentials. 
C)  The cell body would not be able to export products to the axon terminals. 
D)  The cell body would not be able to respond to changes in the distal end of the axon. 
E)  The neuron would be unable to depolarize when stimulated. 
A)  The neuron would not be able to produce neurotransmitters. 
B)  The neuron would not be able to produce action potentials. 
C)  The cell body would not be able to export products to the axon terminals. 
D)  The cell body would not be able to respond to changes in the distal end of the axon. 
E)  The neuron would be unable to depolarize when stimulated.

Question 17

The inactivation gate

Accepted Answer

A)  quickly opens and closes after depolarization. 
B)  is coupled to the movement of the activation gate, but is much slower. 
C)  depends on a change of +100 mV from rest to be signaled to close. 
D)  depends on a loss of Na+ permeability to be triggered. 
E)  depends on a loss of K+ permeability to be triggered. 
A)  quickly opens and closes after depolarization. 
B)  is coupled to the movement of the activation gate, but is much slower. 
C)  depends on a change of +100 mV from rest to be signaled to close. 
D)  depends on a loss of Na+ permeability to be triggered. 
E)  depends on a loss of K+ permeability to be triggered.

Question 18

The amplitude of an action potential depends in part on the amount of sodium in the extracellular fluid.Stanley Student has carefully impaled a neuron with an intracellular electrode.He tests the role of extracellular sodium by changing the concentration in the bathing fluid and recording an action potential after each change.The data he generated are shown in the table,where amplitude listed is the peak amplitude of the action potential; make an appropriate graph.

Accepted Answer

The answer of The amplitude of an action potential depends...

Question 19

Match the term with its description (answers may be used more than once).
-cells that form supportive capsules around cell bodies

Accepted Answer

A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia 
A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia

Question 20

When multiple,possibly even conflicting signals reach a neuron,the neuron evaluates the signals and may respond or not.This property is called

Accepted Answer

A)  temporal summation. 
B)  spatial summation. 
C)  postsynaptic integration. 
D)  graded potentials. 
E)  EPSPs. 
A)  temporal summation. 
B)  spatial summation. 
C)  postsynaptic integration. 
D)  graded potentials. 
E)  EPSPs.

Exam 8: Neurons: Cellular and Network Properties

When comparing action potentials to graded potentials,an/two important distinguishing characteristic/s is/are

Caffeine,nicotine,and alcohol all have effects on

Compare and contrast action and graded potentials.Your answer should include a definition of each,types,characteristics,ionic basis,functions,and anything else necessary to answer the question.

Match the term with its description (answers may be used more than once). -receive(s)most of the incoming synapses

If potassium channels in a neuron were blocked,would it be possible to produce an action potential? If so,describe the probable appearance of these components of a graph: threshold,rising phase,peak,falling phase,undershoot.If not,explain.

Spatial summation refers to

Compare and contrast the communication mechanisms between the nervous and endocrine systems.In other words,how do neurons and neurotransmitters signal to their postsynaptic cells,compared to the way endocrine glands and hormones communicate with their target cells?

Why are mitochondria necessary at axon terminals?

The multiple thin,branched structures on a neuron whose main function is to receive incoming signals are the

Conduction occurs along an axon because

The total amount of neurotransmitter released at the axon terminal is directly related to

If a stimulating electrode is placed in the middle of a resting axon and an above-threshold voltage is applied to the electrode action potentials

How would blocking retrograde transport in an axon affect the activity of a neuron?

The inactivation gate

Match the term with its description (answers may be used more than once). -cells that form supportive capsules around cell bodies

When multiple,possibly even conflicting signals reach a neuron,the neuron evaluates the signals and may respond or not.This property is called

Introduction to Physiology

Molecular Interactions

Compartmentation: Cells and Tissues

Energy and Cellular Metabolism

Membrane Dynamics

Communication, Integration, and Homeostasis

Introduction to the Endocrine System

The Central Nervous System

Sensory Physiology

Efferent Division: Autonomic and Somatic Motor Control

Muscles

Integrative Physiology I: Control of Body Movement

Cardiovascular Physiology

Blood Flow and the Control of Blood Pressure

Blood

Mechanics of Breathing

Gas Exchange and Transport

The Kidneys

Integrative Physiology II: Fluid and Electrolyte Balance

The Digestive System

Metabolism and Energy Balance

Endocrine Control of Growth and Metabolism

The Immune System

Integrative Physiology III: Exercise

Reproduction and Development

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