Campbell Biology Concepts & Connections

Martha R. Taylor, Jean L. Dickey, Eric J. Simon, Kelly Hogan, Jane B. Reece

Chapter 28

Nervous Systems - all with Video Answers

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Chapter Questions

Problem 1

Test your understanding of the nervous system by matching the following labels with their corresponding letters: CNS, effector cells, interneuron, motor neuron, PNS, sensory neuron, sensory receptor, spinal cord, synapse.
(FIGURE CAN'T COPY)

Ali Crampton

Ali Crampton

Numerade Educator

Problem 2

The inside of the neuron has a lower concentration of positive ions than the outside of the neuron. Is the membrane potential positive or negative?

Ali Crampton

Numerade Educator

Problem 3

Fill in the blanks to match some brain structures with their associated functions.
a. If the ______ is severed, the right and left cerebral hemispheres cannot communicate.
b. The ______ and the hippocampus are two components of the______system that help store memories.
c. Accounting for most of the weight of your brain is the highly folded_____; it is the outer region of the _____
d. The_____is responsible for hand-eye coordination.
e. The ____ formation keeps you alert, but the_____with its sleep-inducing center and internal timekeeping region, counteracts alertness.

Ali Crampton

Numerade Educator

Problem 4

What causes a nerve signal to move from one end of a neuron along the length of the neuron to the other end? What is a nerve signal, exactly? Why can't it go backward? How is a nerve signal transmitted from one neuron to the next across a synapse? Write a short paragraph that answers these questions.

Ali Crampton

Numerade Educator

Problem 5

Joe accidentally touched a hot pan. His arm jerked back, and an instant later, he felt a burning pain. How would you explain the fact that his arm moved before he felt the pain?
a. His limbic system blocked the pain momentarily, but the important pain signals eventually got through.
b. His response was a spinal cord reflex that occurred before the pain signals reached the brain.
c. Motor neurons are myelinated; sensory neurons are not. The signals traveled faster to his muscles.
d. This scenario is not actually possible. The brain must register pain before a person can react.

Ali Crampton

Numerade Educator

Problem 6

Which division of the autonomic nervous system would you expect to be activated if a person heard an intruder at the front door?
a. parasympathetic
b. sympathetic
c. enteric

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Numerade Educator

Problem 7

Anesthetics block pain by blocking the transmission of nerve signals. Which of these three chemicals might work as anesthetics? (Choose all that apply and explain your selections.)
a. a chemical that prevents the opening of voltage-gated $\mathrm{Na}^{+}$ channels in membranes
b. a chemical that inhibits the enzymes that degrade neurotransmitters
c. a chemical that blocks neurotransmitter receptors

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Numerade Educator

Problem 8

A proposal to test an SSRI in a large number of individuals with depression was submitted to the FDA. Through random assignments, half of the patients would be controls, receiving nothing at all, and half the patients would receive the drug in pill form. Patients in both groups would note changes in their own mood in a daily journal. What flaw(s) do you note in this experimental design?

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Numerade Educator

Problem 9

Using microelectrodes, a researcher recorded nerve signals in four neurons in the brain of a snail, called $A, B, C,$ and $D$ in the table below. $A, B,$ and $C$ can all transmit signals to $D .$ In three experiments, the animal was stimulated in different ways. The number of nerve signals transmitted per second by each of the cells is recorded in the table. Write a short paragraph explaining the different results of the three experiments.
$$\begin{array}{|lllll|}
\hline & \text { A } & \text { B } & \text { c } & \text { D } \\
& & \text { Signals/sec } & \\
\hline \text { Experiment } \# 1 & 50 & 0 & 40 & 30 \\
\hline \text { Experiment } \# 2 & 50 & 0 & 60 & 45 \\
\hline \text { Experiment } \# 3 & 50 & 30 & 60 & 0 \\
\hline
\end{array}$$

Ali Crampton

Numerade Educator

Problem 10

Design an experiment with a group of taxi drivers in a new city to examine the role of neuroplasticity on learning. Assume you have the ability to image their brains to measure changes in the volume of gray matter.

Ali Crampton

Numerade Educator