Question 1

What would be a consequence of a person having Na+ levels in the blood and interstitial fluids that are well below normal?

Accepted Answer

A)  Neurons would not be able to undergo normal action potentials. 
B)  Action potentials would occur with greater frequency. 
C)  Neurons would all be depolarized. 
D)  Neurons would remain refractory following closure of voltage- gated sodium channels. 
E)  K+ channels would open to compensate for changes in membrane potential. 
A)  Neurons would not be able to undergo normal action potentials. 
B)  Action potentials would occur with greater frequency. 
C)  Neurons would all be depolarized. 
D)  Neurons would remain refractory following closure of voltage- gated sodium channels. 
E)  K+ channels would open to compensate for changes in membrane potential. A

Question 2

Which nervous pathway does sensory information travel through to elicit a response in the effector cells?

Accepted Answer

A)  PNS efferent division CNS interneuron PNS afferent division effector 
B)  CNS efferent division CNS interneuron PNS afferent division effector 
C)  CNS afferent division CNS interneuron PNS efferent division effector 
D)  PNS afferent division CNS interneuron PNS efferent division effector 
A)  PNS efferent division CNS interneuron PNS afferent division effector 
B)  CNS efferent division CNS interneuron PNS afferent division effector 
C)  CNS afferent division CNS interneuron PNS efferent division effector 
D)  PNS afferent division CNS interneuron PNS efferent division effector D

Question 3

If a person were to have a stroke in the occipital lobe of the cerebrum, which of the following functions would
Most likely be affected?

Accepted Answer

A)  sense of touch 
B)  sense of hearing 
C)  sense of taste 
D)  sense of sight 
A)  sense of touch 
B)  sense of hearing 
C)  sense of taste 
D)  sense of sight D

Question 4

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

Accepted Answer

A)  Na+  
B)  Mg++  
C)  Cl-  
D)  Ca++  
E)  K+ 
A)  Na+  
B)  Mg++  
C)  Cl-  
D)  Ca++  
E)  K+

Question 5

Why do Na+ ions enter the cell when voltage- gated Na+ channels are opened in neurons?

Accepted Answer

A)  because the Na+ concentration is much higher outside the cell than it is inside 
B)  because the Na+ ions are attracted to the negatively charged interior 
C)  because the Na+ ions are actively transported by the sodium- potassium pump into the cell 
D)  both A and B 
E)  both A and C 
A)  because the Na+ concentration is much higher outside the cell than it is inside 
B)  because the Na+ ions are attracted to the negatively charged interior 
C)  because the Na+ ions are actively transported by the sodium- potassium pump into the cell 
D)  both A and B 
E)  both A and C

Question 6

Neurotransmitters categorized as inhibitory are expected to

Accepted Answer

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

Question 7

Why are action potentials usually conducted in one direction?

Accepted Answer

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

Question 8

If the activity of the sodium-potassium pump was completely stopped, what would happen to the neuron's membrane potential?

Accepted Answer

A)  no effect 
B)  slow rise in membrane potential 
C)  immediate loss of action potentials 
D)  immediate loss of resting potential 
A)  no effect 
B)  slow rise in membrane potential 
C)  immediate loss of action potentials 
D)  immediate loss of resting potential

Question 9

Action potentials are normally generated at the axon hillock and propagated down the axon away from the cell body. If you experimentally depolarized an axon to the threshold level at a point halfway down the axon, what would happen?

Accepted Answer

A)  An action potential would be generated that would travel to the synapse with the next neuron. 
B)  An action potential would be generated that would travel back towards the cell body. 
C)  No action potential could be generated at this location. 
D)  Answers A and B both apply. 
A)  An action potential would be generated that would travel to the synapse with the next neuron. 
B)  An action potential would be generated that would travel back towards the cell body. 
C)  No action potential could be generated at this location. 
D)  Answers A and B both apply.

Question 10

Where are the sodium channels that trigger an action potential located?

Accepted Answer

A)  axon dendrite 
B)  axon hillock 
C)  axon terminal 
D)  axon cell body 
A)  axon dendrite 
B)  axon hillock 
C)  axon terminal 
D)  axon cell body

Question 11

The corpus callosum is a network of axons that connects the two hemispheres of the cerebrum. What do you hypothesize the primary function of the corpus callosum is?

Accepted Answer

A)  structural support for both hemispheres 
B)  transport of proteins between the hemispheres 
C)  source of nutrients for both hemispheres 
D)  communication between the hemispheres 
A)  structural support for both hemispheres 
B)  transport of proteins between the hemispheres 
C)  source of nutrients for both hemispheres 
D)  communication between the hemispheres

Question 12

Figure 43.1
-Which letter on Figure 43.1 corresponds to the action of the sodium- potassium pump and potassium leak channels?

Accepted Answer

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

Question 13

Figure 43.1
-How do myelin sheaths increase the speed with which action potentials are propagated along an axon?

Accepted Answer

A)  They increase the permeability of Na+ ions in the plasma membrane. 
B)  They cause action potentials to "jump" down the axon rather than travel in a continuous path along every site on the axon. 
C)  They amplify the action potential by increasing sodium influx along the entire distance of the neuron. 
D)  All of the above answers apply. 
A)  They increase the permeability of Na+ ions in the plasma membrane. 
B)  They cause action potentials to "jump" down the axon rather than travel in a continuous path along every site on the axon. 
C)  They amplify the action potential by increasing sodium influx along the entire distance of the neuron. 
D)  All of the above answers apply.

Question 14

How could you increase the magnitude of inhibitory postsynaptic potentials IPSPs) generated at a synapse?

Accepted Answer

A)  Increase K+ permeability. 
B)  Increase the influx of calcium. 
C)  Increase sodium- potassium pump activity. 
D)  All of the above apply. 
A)  Increase K+ permeability. 
B)  Increase the influx of calcium. 
C)  Increase sodium- potassium pump activity. 
D)  All of the above apply.

Question 15

What type of neuron can exist entirely within the central nervous system CNS)?

Accepted Answer

A)  interneuron 
B)  motor neuron 
C)  sensory neuron 
D)  A and B 
E)  all of the above 
A)  interneuron 
B)  motor neuron 
C)  sensory neuron 
D)  A and B 
E)  all of the above

Question 16

Functional studies of the human brain have involved

Accepted Answer

A)  lesion studies of individuals with damage to particular brain regions. 
B)  direct electrical stimulation of regions of cerebral cortex. 
C)  recording from single neurons during memory tasks. 
D)  both A and B. 
E)  all of the above. 
A)  lesion studies of individuals with damage to particular brain regions. 
B)  direct electrical stimulation of regions of cerebral cortex. 
C)  recording from single neurons during memory tasks. 
D)  both A and B. 
E)  all of the above.

Question 17

You are walking your dog at night in the forest. Your dog barks at a strange noise and you are startled. Which of the following physiological responses are most likely to occur?

Accepted Answer

A)  the gallbladder is stimulated to release bile 
B)  pupils dilate 
C)  heartbeat is slowed 
D)  digestive activity is stimulated 
A)  the gallbladder is stimulated to release bile 
B)  pupils dilate 
C)  heartbeat is slowed 
D)  digestive activity is stimulated

Question 18

If an action potential is triggered in a neuron, what must have happened?

Accepted Answer

A)  membrane potential was reached 
B)  threshold potential was reached 
C)  resting potential was reached 
A)  membrane potential was reached 
B)  threshold potential was reached 
C)  resting potential was reached

Question 19

The autonomic nervous system does NOT control

Accepted Answer

A)  stomach activity. 
B)  pupil dilation and constriction. 
C)  airway diameter. 
D)  heart rate. 
E)  contraction of skeletal muscle. 
A)  stomach activity. 
B)  pupil dilation and constriction. 
C)  airway diameter. 
D)  heart rate. 
E)  contraction of skeletal muscle.

Question 20

If twice as many inhibitory postsynaptic potentials IPSPs) as excitatory postsynaptic potentials EPSPs) arrive at a postsynaptic neuron in close proximity, is the integration of signals by the postsynaptic neuron likely to produce an action potential?

Accepted Answer

A)  yes 
B)  no 
A)  yes 
B)  no

Exam 43: Animal Nervous Systems

What would be a consequence of a person having Na+ levels in the blood and interstitial fluids that are well below normal?

Which nervous pathway does sensory information travel through to elicit a response in the effector cells?

If a person were to have a stroke in the occipital lobe of the cerebrum, which of the following functions would Most likely be affected?

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

Why do Na+ ions enter the cell when voltage- gated Na+ channels are opened in neurons?

Neurotransmitters categorized as inhibitory are expected to

Why are action potentials usually conducted in one direction?

If the activity of the sodium-potassium pump was completely stopped, what would happen to the neuron's membrane potential?

Action potentials are normally generated at the axon hillock and propagated down the axon away from the cell body. If you experimentally depolarized an axon to the threshold level at a point halfway down the axon, what would happen?

Where are the sodium channels that trigger an action potential located?

The corpus callosum is a network of axons that connects the two hemispheres of the cerebrum. What do you hypothesize the primary function of the corpus callosum is?

Figure 43.1 -Which letter on Figure 43.1 corresponds to the action of the sodium- potassium pump and potassium leak channels?

Figure 43.1 -How do myelin sheaths increase the speed with which action potentials are propagated along an axon?

How could you increase the magnitude of inhibitory postsynaptic potentials IPSPs) generated at a synapse?

What type of neuron can exist entirely within the central nervous system CNS)?

Functional studies of the human brain have involved

You are walking your dog at night in the forest. Your dog barks at a strange noise and you are startled. Which of the following physiological responses are most likely to occur?

If an action potential is triggered in a neuron, what must have happened?

The autonomic nervous system does NOT control

If twice as many inhibitory postsynaptic potentials IPSPs) as excitatory postsynaptic potentials EPSPs) arrive at a postsynaptic neuron in close proximity, is the integration of signals by the postsynaptic neuron likely to produce an action potential?

Biology and the Tree of Life

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Nucleic Acids and the Rna World

An Introduction to Carbohydrates

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What would be a consequence of a person having Na⁺levels in the blood and interstitial fluids that are well below normal?

Why do Na⁺ions enter the cell when voltage- gated Na⁺channels are opened in neurons?