Question 1

The outside of a neuron is positively charged at resting potential.Why don't negative ions exit from the cell to normalize charge across the membrane?

Accepted Answer

A)  The positive charge outside the cell repels negative ions.
B)  There are no negative ions inside the cell.
C)  All of the chloride ions are already outside the cell.
D)  The negative charge inside the cell is carried by large proteins that cannot diffuse through the membrane.E) B) and C)
F) A) and D)

Question 2

A Hawaiian legend tells of a village that angered a shark god.In revenge, a "seaweed" began to grow in the tidepools that killed anyone who touched it.In fact, this "limu-make-o-Hana" -- a zoanthid cnidarian -- contains a palytoxin that locks the sodium-potassium pump open, allowing free flow of ions.If a villager suffers palytoxin poisoning, which way will the ions in his neurons flow?

Accepted Answer

A)  all ions will flow out
B)  potassium in, sodium out
C)  chloride and sodium out, potassium in
D)  sodium in, potassium outE) A) and B)
F) A) and C)

Question 3

In contrast to these toxins, strychnine acts postsynaptically, to block glycine from binding to receptors on motor neurons.Would you expect the symptoms of strychnine poisoning to be more similar to those of botulinum or tetanus toxin?

Accepted Answer

A)  botulinum
B)  tetanus toxin
C)  botulinum.D) A) and B)
E) A) and C)

Question 4

How do temporal and spatial summation improve the processing power of the brain?

Accepted Answer

A)  Temporal summation allows circadian rhythms to regulate neuronal activity.Spatial summation allows latitude to regulate neuronal activity.
B)  Temporal summation allows a neuron to fire prolonged action potentials, and spatial summation allows a neuron to synapse onto new targets.
C)  Temporal and spatial summation both make the neuron more likely to fire action potentials.
D)  Temporal summation allows a neuron to recognize a persistent signal from a single presynaptic cell, and spatial summation allows a neuron to recognize a broad signal from multiple presynaptic cells.E) All of the above
F) A) and B)

Question 5

Is the resting membrane potential of a neuron closer to the equilibrium potential for K+ or Na+?

Accepted Answer

A)  K+
B)  Na+
C)  It is an average of the two.D) A) and C)
E) All of the above

Question 6

When acetylcholine stimulates the opening of ligand-gated ion channels on a postsynaptic cell, what is this event called?

Accepted Answer

A)  neuromuscular junction
B)  temporal summation
C)  inhibitory postsynaptic potential (IPSP) 
D)  excitatory postsynaptic potential (EPSP) E) C) and D)
F) B) and D)

Question 7

Marathon runners are encouraged to stop at water stations along the course to stay hydrated.However, occasionally a runner drinks too much water and suffers from hyponatremia, or "water intoxication".While water itself is not toxic, drinking too much can upset ion balance in the extracellular space.Based on what you know about ions and nerve signaling, the levels of which important ion are most likely to be disrupted in hyponatremia?

Accepted Answer

A)  hydrogen
B)  potassium
C)  calcium
D)  sodiumE) A) and B)
F) All of the above

Question 8

Since there is a larger concentration of potassium ions inside a neuron, why is the inside of the neuron negative (-70mV)  relative to the outside?

Accepted Answer

A)  Potassium ions carry a negative charge.
B)  Negatively-charged proteins inside the cell counteract the charge of the potassium ions.
C)  The negative sign is just a historical convention.
D)  The high concentration of sodium ions outside the cell makes the inside negative by comparison.E) A) and B)
F) A) and C)

Question 9

Damage to the substantia nigra, a specific region of the basal ganglia, can produce the resting muscle tremors characteristic of what disease?

Accepted Answer

A)  epilepsy
B)  Parkinson disease
C)  seizures
D)  Alzheimer diseaseE) A) and B)
F) A) and C)

Question 10

In early vertebrates, which component of the brain was devoted largely to coordinating motor reflexes?

Accepted Answer

A)  thalamus
B)  forebrain
C)  midbrain
D)  hindbrainE) B) and D)
F) A) and B)

Question 11

True or false: When a neuron is not firing, the sodium-potassium pump is inactive.

Accepted Answer

A) True 
 B)False

Question 12

How does the resting potential of a typical neuron compare to that of a 1.5V AA alkaline battery?

Accepted Answer

A)  A typical neuron has a resting potential of -70mV, or about 5% the voltage of the battery.
B)  A typical neuron has a resting potential of -70V, or about 50x the voltage of the battery.
C)  A typical neuron has a resting potential of +70mV, or about 5% the voltage of the battery.
D)  A typical neuron has a resting potential of +70V, or about 50x the voltage of the battery.E) B) and D)
F) B) and C)

Question 13

What would happen if the G-protein coupled receptor in heart cells that binds to ACh had a mutation that caused it to bind more tightly to the G-protein alpha subunit?

Accepted Answer

A)  G-protein activation and K+ channel opening would happen more quickly.Heart rate may remain abnormally low, impairing response to stress.
B)  This would lead to K+ flow out of heart cells, causing increased hyperpolarization.
C)  G-protein activation and K+ channel opening would be slowed.Heart rate may remain abnormally high, especially following stress.
D)  This would lead to K+ flow into heart cells, causing increased depolarization.E) C) and D)
F) B) and D)

Question 14

You accidentally consume botulinum toxin by eating a contaminated can of sausages.What do you predict will be the most harmful physiological effect?

Accepted Answer

A)  slowed action potential conduction
B)  respiratory failure due to spastic paralysis (constant muscle contraction) 
C)  respiratory failure due to flaccid paralysis (relaxed muscles) 
D)  pupil dilationE) None of the above
F) A) and B)

Question 15

How can mutations in different genes, functioning in different cells, lead to the same disease? From the following, choose the best responses to complete the sentences: "Physiological function requires that multiple cells work together.Various defects in different cells can impair function, leading to ___________ that are indistinguishable at the level of the whole organism.In Charcot-Marie-Tooth disease, motor nerve function can be impaired either by a problem within _______________ , or a problem in __________________ causing _______________."

Accepted Answer

A)  defects; somatic cells; oligodendrocytes; demyelination
B)  symptoms; motor neurons; Schwann cells; demyelination
C)  symptoms; sensory neurons; Schwann cells; fast axonal transport
D)  genotypes; dendrites; axons; fast axonal transportE) C) and D)
F) A) and B)

Question 16

What is the site of primary sensory integration in the brain?

Accepted Answer

A)  medulla oblongata
B)  cerebrum
C)  cerebellum
D)  thalamusE) A) and D)
F) A) and B)

Question 17

Genetic studies have found that Charcot-Marie-Tooth may be caused by a mutation in the gene Mitofusin-2 (MFN2) , which causes mitochondria to form large clumps.In what area of a neuron are these clumps most likely to cause a problem?

Accepted Answer

A)  axon
B)  synapse
C)  soma
D)  dendriteE) A) and B)
F) All of the above

Question 18

If K+ can exit the cell through leak channels, why don't they flow out until there are equal concentrations on both sides of the membrane?

Accepted Answer

A)  K+ can act as an enzymatic cofactor, and most K+ ions are bound to cellular enzymes.
B)  The leak channels allow a very slow leak that cannot keep pace with active import of K+ ions.
C)  Chelator molecules trap K+ on the inside of the membrane.
D)  The negative electrical potential inside the cell creates a force that holds the K+ ions in.E) C) and D)
F) A) and B)

Question 19

You are an EMT on duty for the marathon.It is an extremely hot day.You say to your partner, "This weather is likely to _____________ the risk of hyponatremia, because ______________ will cause the athletes to lose ______________."

Accepted Answer

A)  increase, sweating, sodium
B)  decrease, urination, calcium
C)  decrease, shivering, potassium
D)  increase, panting, oxygenE) A) and B)
F) All of the above

Question 20

What additional factor is required to mediate the parasympathetic effects of acetylcholine?

Accepted Answer

A)  G-protein coupled receptor
B)  GABA
C)  AMPAR
D)  habituationE) A) and C)
F) A) and D)

Exam 43: The Nervous System

What would happen if the G-protein coupled receptor in heart cells that binds to ACh had a mutation that caused it to bind more tightly to the G-protein alpha subunit?

Correct Answer
verified

Correct Answer
verified

Damage to the substantia nigra, a specific region of the basal ganglia, can produce the resting muscle tremors characteristic of what disease?

Correct Answer
verified

You accidentally consume botulinum toxin by eating a contaminated can of sausages.What do you predict will be the most harmful physiological effect?

Correct Answer
verified

Is the resting membrane potential of a neuron closer to the equilibrium potential for K⁺ or Na⁺?

Correct Answer
verified

Genetic studies have found that Charcot-Marie-Tooth may be caused by a mutation in the gene Mitofusin-2 (MFN2) , which causes mitochondria to form large clumps.In what area of a neuron are these clumps most likely to cause a problem?

Correct Answer
verified

When acetylcholine stimulates the opening of ligand-gated ion channels on a postsynaptic cell, what is this event called?

Correct Answer
verified

What additional factor is required to mediate the parasympathetic effects of acetylcholine?

Correct Answer
verified

Correct Answer
verified

True or false: When a neuron is not firing, the sodium-potassium pump is inactive.

Correct Answer
verified

In contrast to these toxins, strychnine acts postsynaptically, to block glycine from binding to receptors on motor neurons.Would you expect the symptoms of strychnine poisoning to be more similar to those of botulinum or tetanus toxin?

Correct Answer
verified

If K⁺ can exit the cell through leak channels, why don't they flow out until there are equal concentrations on both sides of the membrane?

Correct Answer
verified

What is the site of primary sensory integration in the brain?

Correct Answer
verified

How does the resting potential of a typical neuron compare to that of a 1.5V AA alkaline battery?

Correct Answer
verified

Since there is a larger concentration of potassium ions inside a neuron, why is the inside of the neuron negative (-70mV) relative to the outside?

Correct Answer
verified

How do temporal and spatial summation improve the processing power of the brain?

Correct Answer
verified

You are an EMT on duty for the marathon.It is an extremely hot day.You say to your partner, "This weather is likely to _ the risk of hyponatremia, because will cause the athletes to lose ____."

Correct Answer
verified

The outside of a neuron is positively charged at resting potential.Why don't negative ions exit from the cell to normalize charge across the membrane?

Correct Answer
verified

Correct Answer
verified

In early vertebrates, which component of the brain was devoted largely to coordinating motor reflexes?

Correct Answer
verified

Exam 43: The Nervous System

What would happen if the G-protein coupled receptor in heart cells that binds to ACh had a mutation that caused it to bind more tightly to the G-protein alpha subunit?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Damage to the substantia nigra, a specific region of the basal ganglia, can produce the resting muscle tremors characteristic of what disease?

Correct AnswerverifiedShow Answer

You accidentally consume botulinum toxin by eating a contaminated can of sausages.What do you predict will be the most harmful physiological effect?

Correct AnswerverifiedShow Answer

Is the resting membrane potential of a neuron closer to the equilibrium potential for K+ or Na+?

Correct AnswerverifiedShow Answer

Genetic studies have found that Charcot-Marie-Tooth may be caused by a mutation in the gene Mitofusin-2 (MFN2) , which causes mitochondria to form large clumps.In what area of a neuron are these clumps most likely to cause a problem?

Correct AnswerverifiedShow Answer

When acetylcholine stimulates the opening of ligand-gated ion channels on a postsynaptic cell, what is this event called?

Correct AnswerverifiedShow Answer

What additional factor is required to mediate the parasympathetic effects of acetylcholine?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

True or false: When a neuron is not firing, the sodium-potassium pump is inactive.

Correct AnswerverifiedShow Answer

In contrast to these toxins, strychnine acts postsynaptically, to block glycine from binding to receptors on motor neurons.Would you expect the symptoms of strychnine poisoning to be more similar to those of botulinum or tetanus toxin?

Correct AnswerverifiedShow Answer

If K+ can exit the cell through leak channels, why don't they flow out until there are equal concentrations on both sides of the membrane?

Correct AnswerverifiedShow Answer

What is the site of primary sensory integration in the brain?

Correct AnswerverifiedShow Answer

How does the resting potential of a typical neuron compare to that of a 1.5V AA alkaline battery?

Correct AnswerverifiedShow Answer

Since there is a larger concentration of potassium ions inside a neuron, why is the inside of the neuron negative (-70mV) relative to the outside?

Correct AnswerverifiedShow Answer

How do temporal and spatial summation improve the processing power of the brain?

Correct AnswerverifiedShow Answer

You are an EMT on duty for the marathon.It is an extremely hot day.You say to your partner, "This weather is likely to _____________ the risk of hyponatremia, because ______________ will cause the athletes to lose ______________."

Correct AnswerverifiedShow Answer

The outside of a neuron is positively charged at resting potential.Why don't negative ions exit from the cell to normalize charge across the membrane?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In early vertebrates, which component of the brain was devoted largely to coordinating motor reflexes?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Is the resting membrane potential of a neuron closer to the equilibrium potential for K⁺ or Na⁺?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

If K⁺ can exit the cell through leak channels, why don't they flow out until there are equal concentrations on both sides of the membrane?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

You are an EMT on duty for the marathon.It is an extremely hot day.You say to your partner, "This weather is likely to _ the risk of hyponatremia, because will cause the athletes to lose ____."

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified