Question 1

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it. This is an example of ________.

Accepted Answer

A)  a voltage-gated sodium channel 
B)  a voltage-gated potassium channel 
C)  a ligand-gated sodium channel 
D)  a second-messenger-gated sodium channel 
E)  a chemical that inhibits action potentials 
A)  a voltage-gated sodium channel 
B)  a voltage-gated potassium channel 
C)  a ligand-gated sodium channel 
D)  a second-messenger-gated sodium channel 
E)  a chemical that inhibits action potentials

Question 2

Two fundamental concepts about the ion channels of a "resting" neuron are that the channels ________.

Accepted Answer

A)  are always open, but the concentration gradients of ions frequently change 
B)  are always closed, but ions move closer to the channels during excitation 
C)  open and close depending on stimuli and are specific as to which ion can traverse them 
D)  open and close depending on chemical messengers and are nonspecific as to which ion can traverse them 
E)  open in response to stimuli and then close simultaneously, in unison 
A)  are always open, but the concentration gradients of ions frequently change 
B)  are always closed, but ions move closer to the channels during excitation 
C)  open and close depending on stimuli and are specific as to which ion can traverse them 
D)  open and close depending on chemical messengers and are nonspecific as to which ion can traverse them 
E)  open in response to stimuli and then close simultaneously, in unison

Question 3

Damage to the frontal lobe, such as experienced by Phineas Gage, leads to ________.

Accepted Answer

A)  the loss of a sense of balance 
B)  the loss of all short-term memory 
C)  altered emotional responses 
D)  greatly increased long-term memory 
A)  the loss of a sense of balance 
B)  the loss of all short-term memory 
C)  altered emotional responses 
D)  greatly increased long-term memory

Question 4

Which of the following ions is most likely to cross the plasma membrane of a resting neuron?

Accepted Answer

A)  K+ 
B)  Na+ 
C)  Ca2+ 
D)  Cl− 
E)  Mg2+ 
A)  K+ 
B)  Na+ 
C)  Ca2+ 
D)  Cl− 
E)  Mg2+

Question 5

A common feature of action potentials is that they ________.

Accepted Answer

A)  cause the membrane to hyperpolarize and then depolarize 
B)  can undergo temporal and spatial summation 
C)  are triggered by a depolarization that reaches the threshold potential 
D)  move at the same speed along all axons 
E)  require the diffusion of Na+ and K+ through ligand-gated channels to propagate 
A)  cause the membrane to hyperpolarize and then depolarize 
B)  can undergo temporal and spatial summation 
C)  are triggered by a depolarization that reaches the threshold potential 
D)  move at the same speed along all axons 
E)  require the diffusion of Na+ and K+ through ligand-gated channels to propagate

Question 6

In a synapse, what initiates the release of neurotransmitter?

Accepted Answer

A)  when an action potential depolarizes the presynaptic membrane 
B)  when threshold potential is reached 
C)  when enough voltage-gated sodium channels open to release calcium into the synapse 
D)  the presence of gap junctions joining the synaptic membranes 
A)  when an action potential depolarizes the presynaptic membrane 
B)  when threshold potential is reached 
C)  when enough voltage-gated sodium channels open to release calcium into the synapse 
D)  the presence of gap junctions joining the synaptic membranes

Question 7

Refer to the following graph of an action potential to answer the question(s) below.  
-The cell is not hyperpolarized; however, repolarization is in progress, as the sodium channels are closing or closed, and many potassium channels have opened at label ________.

Accepted Answer

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

Question 8

An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to ________.

Accepted Answer

A)  K+ 
B)  Na+ 
C)  Ca2+ 
D)  ATP 
E)  acetylcholine 
A)  K+ 
B)  Na+ 
C)  Ca2+ 
D)  ATP 
E)  acetylcholine

Question 9

Although an exact count is not available, it is likely that the human brain has as many as ________.

Accepted Answer

A)  500,000 neurons 
B)  1 million neurons 
C)  10 million neurons 
D)  100 billion neurons 
E)  1 trillion neurons 
A)  500,000 neurons 
B)  1 million neurons 
C)  10 million neurons 
D)  100 billion neurons 
E)  1 trillion neurons

Question 10

Why are action potentials usually conducted in one direction?

Accepted Answer

A)  The nodes of Ranvier conduct potentials in one direction. 
B)  The brief refractory period prevents reopening of voltage-gated Na+ channels. 
C)  The axon hillock has a higher membrane potential than the terminals of the axon. 
D)  Ions can flow along the axon in only one direction. 
E)  Voltage-gated channels for both Na+ and K+ open in only one direction. 
A)  The nodes of Ranvier conduct potentials in one direction. 
B)  The brief refractory period prevents reopening of voltage-gated Na+ channels. 
C)  The axon hillock has a higher membrane potential than the terminals of the axon. 
D)  Ions can flow along the axon in only one direction. 
E)  Voltage-gated channels for both Na+ and K+ open in only one direction.

Question 11

In a simple synapse, neurotransmitter chemicals are received by ________.

Accepted Answer

A)  the postsynaptic membrane 
B)  the presynaptic membrane 
C)  axon hillocks 
D)  cell bodies 
E)  ducts on the smooth endoplasmic reticulum 
A)  the postsynaptic membrane 
B)  the presynaptic membrane 
C)  axon hillocks 
D)  cell bodies 
E)  ducts on the smooth endoplasmic reticulum

Question 12

If you experimentally increase the concentration of K+ inside a cell while maintaining other ion concentrations as they were, what would happen to the cell's membrane potential?

Accepted Answer

A)  The membrane potential would become more negative. 
B)  The membrane potential would become less negative. 
C)  The membrane potential would first become more negative then rebound to be positive. 
D)  The membrane potential would remain the same. 
A)  The membrane potential would become more negative. 
B)  The membrane potential would become less negative. 
C)  The membrane potential would first become more negative then rebound to be positive. 
D)  The membrane potential would remain the same.

Question 13

Forming new long-term memories is strikingly disrupted after damage to the ________.

Accepted Answer

A)  thalamus 
B)  hypothalamus 
C)  cerebral cortex 
D)  somatosensory cortex 
E)  primary motor cortex 
A)  thalamus 
B)  hypothalamus 
C)  cerebral cortex 
D)  somatosensory cortex 
E)  primary motor cortex

Question 14

Immediately after an action potential passes along an axon, it is not possible to generate a second action potential. Thus, we state that the membrane is briefly ________.

Accepted Answer

A)  hyperexcitable 
B)  refractory 
C)  fully depolarized 
D)  above threshold 
E)  at the equilibrium potential 
A)  hyperexcitable 
B)  refractory 
C)  fully depolarized 
D)  above threshold 
E)  at the equilibrium potential

Question 15

The activation of the parasympathetic branch of the autonomic nervous system is associated with ________.

Accepted Answer

A)  resting and digesting 
B)  release of epinephrine into the blood 
C)  increased metabolic rate 
D)  fight-or-flight responses 
E)  intensive aerobic exercise 
A)  resting and digesting 
B)  release of epinephrine into the blood 
C)  increased metabolic rate 
D)  fight-or-flight responses 
E)  intensive aerobic exercise

Question 16

After the depolarization phase of an action potential, the resting potential is restored by ________.

Accepted Answer

A)  the opening of sodium activation gates 
B)  the opening of voltage-gated potassium channels and the closing of sodium channels 
C)  a decrease in the membrane's permeability to potassium and chloride ions 
D)  a brief inhibition of the sodium-potassium pump 
E)  the opening of more voltage-gated sodium channels 
A)  the opening of sodium activation gates 
B)  the opening of voltage-gated potassium channels and the closing of sodium channels 
C)  a decrease in the membrane's permeability to potassium and chloride ions 
D)  a brief inhibition of the sodium-potassium pump 
E)  the opening of more voltage-gated sodium channels

Question 17

In multiple sclerosis the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?
I. Action potentials move in the opposite direction on the axon.
II. Action potentials move more slowly along the axon.
III. No action potentials are transmitted.

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

Question 18

ATP hydrolysis directly powers the movement of ________.

Accepted Answer

A)  K+ out of cells 
B)  Na+ out of cells 
C)  Na+ into cells 
D)  Ca2+ into cells 
E)  Cl− into cells 
A)  K+ out of cells 
B)  Na+ out of cells 
C)  Na+ into cells 
D)  Ca2+ into cells 
E)  Cl− into cells

Question 19

Neurotransmitters categorized as inhibitory are expected to ________.

Accepted Answer

A)  act independently of their receptor proteins 
B)  close potassium channels 
C)  open sodium channels 
D)  close chloride channels 
E)  hyperpolarize the membrane 
A)  act independently of their receptor proteins 
B)  close potassium channels 
C)  open sodium channels 
D)  close chloride channels 
E)  hyperpolarize the membrane

Question 20

Preparation for the fight-or-flight response includes activation of the ________ nervous system.

Accepted Answer

A)  sympathetic 
B)  somatic 
C)  central 
D)  visceral 
E)  parasympathetic 
A)  sympathetic 
B)  somatic 
C)  central 
D)  visceral 
E)  parasympathetic

Exam 43: Animal Nervous Systems

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it. This is an example of ________.

Two fundamental concepts about the ion channels of a "resting" neuron are that the channels ________.

Damage to the frontal lobe, such as experienced by Phineas Gage, leads to ________.

Which of the following ions is most likely to cross the plasma membrane of a resting neuron?

A common feature of action potentials is that they ________.

In a synapse, what initiates the release of neurotransmitter?

Refer to the following graph of an action potential to answer the question(s) below. -The cell is not hyperpolarized; however, repolarization is in progress, as the sodium channels are closing or closed, and many potassium channels have opened at label ________.

An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to ________.

Although an exact count is not available, it is likely that the human brain has as many as ________.

Why are action potentials usually conducted in one direction?

In a simple synapse, neurotransmitter chemicals are received by ________.

If you experimentally increase the concentration of K+ inside a cell while maintaining other ion concentrations as they were, what would happen to the cell's membrane potential?

Forming new long-term memories is strikingly disrupted after damage to the ________.

Immediately after an action potential passes along an axon, it is not possible to generate a second action potential. Thus, we state that the membrane is briefly ________.

The activation of the parasympathetic branch of the autonomic nervous system is associated with ________.

After the depolarization phase of an action potential, the resting potential is restored by ________.

ATP hydrolysis directly powers the movement of ________.

Neurotransmitters categorized as inhibitory are expected to ________.

Preparation for the fight-or-flight response includes activation of the ________ nervous system.

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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