Exam 43: The Nervous System

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

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

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?

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

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?

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

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

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

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 ______________."

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?

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?

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 _______________."

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?

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

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

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?

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?

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

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?

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