Question 1

Neural transmission across a mammalian synapse is accomplished by ________.

Accepted Answer

A)  the movement of sodium and potassium ions from the presynaptic neuron into the postsynaptic neuron 
B)  impulses traveling as electrical currents across the synapse 
C)  impulses causing the release of a chemical signal and its diffusion across the synapse 
D)  impulses ricocheting back and forth across the synapse 
E)  the movement of calcium ions from the presynaptic into the postsynaptic neuron 
A)  the movement of sodium and potassium ions from the presynaptic neuron into the postsynaptic neuron 
B)  impulses traveling as electrical currents across the synapse 
C)  impulses causing the release of a chemical signal and its diffusion across the synapse 
D)  impulses ricocheting back and forth across the synapse 
E)  the movement of calcium ions from the presynaptic into the postsynaptic neuron

Question 2

The motor (somatic nervous) system can alter the activities of its targets, the skeletal muscle fibers, because ________.

Accepted Answer

A)  it is electrically coupled by gap junctions to the muscles 
B)  its signals bind to receptor proteins at synapses on the muscles 
C)  its signals reach the muscles via the blood 
D)  its light pulses activate contraction in the muscles 
E)  it is connected to the internal neural network of the muscles 
A)  it is electrically coupled by gap junctions to the muscles 
B)  its signals bind to receptor proteins at synapses on the muscles 
C)  its signals reach the muscles via the blood 
D)  its light pulses activate contraction in the muscles 
E)  it is connected to the internal neural network of the muscles

Question 3

Refer to the following graph of an action potential to answer the question(s) below.  
-The minimum depolarization needed to operate the voltage-gated sodium and potassium channels is indicated by the label ________.

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 4

Hyperpolarization of a membrane can be induced by ________.

Accepted Answer

A)  increasing its membrane's permeability to Na+ 
B)  decreasing its membrane's permeability to H+ 
C)  decreasing its membrane's permeability to Cl− 
D)  increasing its membrane's permeability to Ca++ 
E)  increasing its membrane's permeability to K+ 
A)  increasing its membrane's permeability to Na+ 
B)  decreasing its membrane's permeability to H+ 
C)  decreasing its membrane's permeability to Cl− 
D)  increasing its membrane's permeability to Ca++ 
E)  increasing its membrane's permeability to K+

Question 5

When two excitatory postsynaptic potentials (EPSPs) occur at a single synapse so rapidly in succession that the postsynaptic neuron's membrane potential has not returned to the resting potential before the second EPSP arrives, the EPSPs add together, producing ________.

Accepted Answer

A)  summation 
B)  inhibition 
C)  tetanus 
D)  the refractory state 
E)  an action potential with an abnormally high peak of depolarization 
A)  summation 
B)  inhibition 
C)  tetanus 
D)  the refractory state 
E)  an action potential with an abnormally high peak of depolarization

Question 6

What type of neuron exists entirely within the central nervous system (CNS)?

Accepted Answer

A)  interneuron 
B)  motor neuron 
C)  sensory neuron 
D)  interneuron and motor neuron 
E)  interneuron, sensory neuron, and motor neuron 
A)  interneuron 
B)  motor neuron 
C)  sensory neuron 
D)  interneuron and motor neuron 
E)  interneuron, sensory neuron, and motor neuron

Question 7

Which of the following statements about action potentials is correct?

Accepted Answer

A)  Action potentials for a given neuron vary in magnitude. 
B)  Action potentials for a given neuron vary in duration. 
C)  Action potentials are propagated down the length of the axon. 
D)  Movement of ions during the action potential occurs mostly through the sodium pump. 
A)  Action potentials for a given neuron vary in magnitude. 
B)  Action potentials for a given neuron vary in duration. 
C)  Action potentials are propagated down the length of the axon. 
D)  Movement of ions during the action potential occurs mostly through the sodium pump.

Question 8

Although the membrane of a "resting" neuron is highly permeable to potassium ions, its membrane potential does not exactly match the equilibrium potential for potassium because the neuronal membrane is also ________.

Accepted Answer

A)  fully permeable to sodium ions 
B)  slightly permeable to sodium ions 
C)  fully permeable to calcium ions 
D)  impermeable to sodium ions 
E)  highly permeable to chloride ions 
A)  fully permeable to sodium ions 
B)  slightly permeable to sodium ions 
C)  fully permeable to calcium ions 
D)  impermeable to sodium ions 
E)  highly permeable to chloride ions

Question 9

The botulinum toxin, which causes botulism, reduces the synaptic release of ________.

Accepted Answer

A)  acetylcholine 
B)  epinephrine 
C)  endorphin 
D)  nitric oxide 
E)  gamma-aminobutyric acid (GAB
A)  
A)  acetylcholine 
B)  epinephrine 
C)  endorphin 
D)  nitric oxide 
E)  gamma-aminobutyric acid (GAB
A)

Question 10

Increased activity in the sympathetic nervous system leads to ________.

Accepted Answer

A)  decreased heart rate 
B)  increased secretion by the pancreas 
C)  increased secretion by the gallbladder 
D)  increased contractions of the stomach 
E)  relaxation of the airways in the lungs 
A)  decreased heart rate 
B)  increased secretion by the pancreas 
C)  increased secretion by the gallbladder 
D)  increased contractions of the stomach 
E)  relaxation of the airways in the lungs

Question 11

-Which letter in the accompanying figure corresponds to closed voltage-gated sodium channels and closed voltage-gated potassium channels?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D

Question 12

The nucleus and most of the organelles in a neuron are located in the ________.

Accepted Answer

A)  dendritic region 
B)  axon hillock 
C)  axon 
D)  cell body 
E)  axon terminals 
A)  dendritic region 
B)  axon hillock 
C)  axon 
D)  cell body 
E)  axon terminals

Question 13

The fastest possible conduction velocity of action potentials is observed in ________.

Accepted Answer

A)  small diameter, non-myelinated neurons 
B)  small diameter, myelinated neurons 
C)  large diameter, non-myelinated neurons 
D)  large diameter, myelinated neurons 
A)  small diameter, non-myelinated neurons 
B)  small diameter, myelinated neurons 
C)  large diameter, non-myelinated neurons 
D)  large diameter, myelinated neurons

Question 14

Neurotransmitters are released from axon terminals via ________.

Accepted Answer

A)  osmosis 
B)  active transport 
C)  diffusion 
D)  transcytosis 
E)  exocytosis 
A)  osmosis 
B)  active transport 
C)  diffusion 
D)  transcytosis 
E)  exocytosis

Question 15

The human knee-jerk reflex requires an intact ________.

Accepted Answer

A)  spinal cord 
B)  hypothalamus 
C)  corpus callosum 
D)  cerebellum 
E)  medulla 
A)  spinal cord 
B)  hypothalamus 
C)  corpus callosum 
D)  cerebellum 
E)  medulla

Question 16

Opening all of the sodium channels of a neuron at rest should move its membrane potential to ________.

Accepted Answer

A)  −90 mV 
B)  −70 mV 
C)  0 mV 
D)  +10 mV 
E)  +40 mV 
A)  −90 mV 
B)  −70 mV 
C)  0 mV 
D)  +10 mV 
E)  +40 mV

Question 17

What happens when a resting neuron's membrane depolarizes?

Accepted Answer

A)  There is a net diffusion of Na+ out of the cell. 
B)  The equilibrium potential for K+ (EK) becomes more positive. 
C)  The neuron's membrane voltage becomes more positive. 
D)  The neuron is less likely to generate an action potential. 
E)  The cell's inside is more negative than the outside. 
A)  There is a net diffusion of Na+ out of the cell. 
B)  The equilibrium potential for K+ (EK) becomes more positive. 
C)  The neuron's membrane voltage becomes more positive. 
D)  The neuron is less likely to generate an action potential. 
E)  The cell's inside is more negative than the outside.

Question 18

The depolarization phase of an action potential requires ________.

Accepted Answer

A)  opening of K+ channels in the membrane 
B)  opening of Na+ channels in the membrane 
C)  opening of Ca2+ channels in the membrane 
D)  a K+ concentration gradient across the membrane 
E)  a Ca2+ concentration gradient across the membrane 
A)  opening of K+ channels in the membrane 
B)  opening of Na+ channels in the membrane 
C)  opening of Ca2+ channels in the membrane 
D)  a K+ concentration gradient across the membrane 
E)  a Ca2+ concentration gradient across the membrane

Question 19

The "selectivity" of a particular ion channel refers to its ________.

Accepted Answer

A)  permitting passage by positive but not negative ions 
B)  permitting passage by negative but not positive ions 
C)  ability to change its size depending on the ion needing transport 
D)  binding with only one type of neurotransmitter 
E)  permitting passage only to a specific ion 
A)  permitting passage by positive but not negative ions 
B)  permitting passage by negative but not positive ions 
C)  ability to change its size depending on the ion needing transport 
D)  binding with only one type of neurotransmitter 
E)  permitting passage only to a specific ion

Question 20

Which of the following manipulations would reduce the release of neurotransmitter from a presynaptic neuron terminal?
I. reduction in extracellular calcium ion concentration at the axon terminal
II. increase in extracellular sodium ion concentrations at the axon terminal
III. addition of tetrodotoxin to the extracellular fluid at the axon terminal

Accepted Answer

A)  only I 
B)  only II 
C)  only III 
D)  only II and III 
E)  only I and II 
A)  only I 
B)  only II 
C)  only III 
D)  only II and III 
E)  only I and II

Exam 43: Animal Nervous Systems

Neural transmission across a mammalian synapse is accomplished by ________.

The motor (somatic nervous) system can alter the activities of its targets, the skeletal muscle fibers, because ________.

Refer to the following graph of an action potential to answer the question(s) below. -The minimum depolarization needed to operate the voltage-gated sodium and potassium channels is indicated by the label ________.

Hyperpolarization of a membrane can be induced by ________.

When two excitatory postsynaptic potentials (EPSPs) occur at a single synapse so rapidly in succession that the postsynaptic neuron's membrane potential has not returned to the resting potential before the second EPSP arrives, the EPSPs add together, producing ________.

What type of neuron exists entirely within the central nervous system (CNS)?

Which of the following statements about action potentials is correct?

Although the membrane of a "resting" neuron is highly permeable to potassium ions, its membrane potential does not exactly match the equilibrium potential for potassium because the neuronal membrane is also ________.

The botulinum toxin, which causes botulism, reduces the synaptic release of ________.

Increased activity in the sympathetic nervous system leads to ________.

-Which letter in the accompanying figure corresponds to closed voltage-gated sodium channels and closed voltage-gated potassium channels?

The nucleus and most of the organelles in a neuron are located in the ________.

The fastest possible conduction velocity of action potentials is observed in ________.

Neurotransmitters are released from axon terminals via ________.

The human knee-jerk reflex requires an intact ________.

Opening all of the sodium channels of a neuron at rest should move its membrane potential to ________.

What happens when a resting neuron's membrane depolarizes?

The depolarization phase of an action potential requires ________.

The "selectivity" of a particular ion channel refers to its ________.

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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