Deck 8: Neurons: the Matter of the Mind

Question 1

In saltatory conduction, nerve impulses jump from one exposed region of the axon to another. This exposed region is called the ________.

A) motor end plate
B) node of Ranvier
C) Schwann cell gap
D) interneurons

Answer 1

B

Question 2

Muscle cells that are not exercised will atrophy, or shrink in size. Lou Gehrig's disease affects nervous tissue but also causes muscle atrophy. What type of nerve cell must be affected to cause this muscle-wasting condition?

A) interneurons
B) sensory neurons
C) neuroglial cells
D) motor neurons

Answer 2

D

Question 3

Which of the following is a chemical signal that diffuses across the gap between adjacent neurons to convey a message to the next cell?

A) neurotransmitter
B) synapse
C) dendrite
D) action potential

Answer 3

A

Question 4

Multiple sclerosis is a disease in which the myelin sheath is destroyed. What will happen to nerve conduction speed in affected neurons?

A) It will slow down dramatically.
B) It will speed up dramatically.
C) It will speed up just a little bit.
D) There will be no effect.

Question 5

The specialized membrane proteins that actively transport sodium and potassium ions across the plasma membrane are known as the ________.

A) sodium-chloride pump
B) sodium-manganese pump
C) sodium-potassium pump
D) sodium pump

Question 6

When traveling down the neuron, which of the following parts of the neuron does the action potential pass through before the axon?

A) glial cell
B) dendrite
C) synapse
D) cell body

Question 7

Which one of the following ions outside the neuron would make it very difficult for a depolarization to occur?

A) potassium
B) sodium
C) chloride
D) manganese

Question 8

Which of these diseases involves the destruction of the myelin sheath on certain neurons within the brain and spinal cord?

A) depression
B) Alzheimer's disease
C) Parkinson's disease
D) multiple sclerosis

Question 9

A nerve impulse does not vary in intensity with regard to the strength of the stimulus. What do we call this phenomenon?

A) resting membrane potential
B) refractory period
C) all-or-nothing principle
D) graded response

Question 10

A neuron's membrane that maintains a charge difference across its surface in which the inside is more negative than the outside is called ________.

A) graded potential
B) resting potential
C) action potential
D) summation

Question 11

Infants require many nutrients early in life, including lipids such as fats. A low-fat diet for infants is not recommended because, among other things, it can affect the development of the nervous system. Why does the developing nervous system need lipids?

A) Glial cells need lipids to produce the myelin sheath.
B) Fats are needed for energy because infants are often on a low-carbohydrate diet.
C) Lipids are needed to produce the polypeptide neurotransmitters used by neurons.
D) Fats are required to generate action potentials on nerve cells.

Question 12

Which type of neuron is found only in the brain and spinal cord?

A) sensory neuron
B) interneuron
C) motor neuron
D) glial cell

Question 13

Inhaling or "huffing" is a way to achieve a high, usually by breathing in a fat-soluble substance. Which of the following structures would be most likely attacked first?

A) myelin sheath
B) axon
C) neuron
D) dendrite

Question 14

A new drug interferes with the function of the dendrites of a neuron. What will happen to this neuron?

A) The neuron will continuously send signals.
B) The neuron cannot be stimulated to send a signal along its axon.
C) The neuron will die off.
D) The neuron will sometimes send signals and will sometimes not send signals.

Question 15

Some drugs modulate the activity of ion channels. For example, Novocain somewhat inhibits the opening of sodium channels. What happens to the threshold of a sensory neuron if this drug is used?

A) It will take less stimulation to reach threshold.
B) It will take more stimulation to reach threshold.
C) Threshold will not change.
D) The nerve will not function and will die off.

Question 16

Which of the following parts of the nervous system is closest to a muscle?

A) neuron
B) interneuron
C) motor neuron
D) neuroglial cell

Question 17

Leprosy destroys nerve tissue, so an afflicted person is likely to hurt his or her foot without even knowing it. Which types of neurons are likely to be affected?

A) neuroglial cells
B) motor neurons
C) sensory neurons
D) interneurons

Question 18

Which type of cell found in the nervous system is the most numerous?

A) neuron
B) neuroglial cell
C) sensory cell
D) Schwann cell

Question 19

Sodium and potassium ions cross the neuron's membrane to cause which of the following processes?

A) action potential
B) passive transport
C) refractory period
D) transmission

Question 20

Ouabain is a chemical used on poison arrows in Africa. It works by inhibiting the sodium-potassium pump. What effect does this chemical have on an action potential?

A) It prevents the stimulation of an action potential by removing sodium from the cell.
B) It immediately causes an action potential to be generated.
C) There is no direct effect because the pump is used to maintain ion distributions, not to cause an action potential.
D) It causes the release of a neurotransmitter that causes an action potential.

Question 21

Look at the accompanying figure. In Step 1 ________ ions enter the neuron, while in Step 2 ________ ions leave the neuron.

Question 22

During an action potential, the ________ ions rush into the axon.

Question 23

Prescription drugs such as Prozac help maintain higher levels of serotonin in the brain. What effect will this have on an individual?

A) It will act as an antidepressant because a lack of serotonin is considered a cause of depression symptoms.
B) It will act to suppress impulsive behavior because too much serotonin causes children to act out.
C) It will cause a patient to be sleepy because serotonin is essential to a good night's sleep.
D) It will cause tetany due to an overproduction of acetylcholine.

Question 24

The jumping of a nerve impulse from one node of Ranvier to the next is known as ________.

Question 25

The combined effects of inhibitory and excitatory effects on a postsynaptic cell will decide whether that cell generates an action potential. This principle is called ________.

A) threshold
B) internalization
C) summation
D) potentiation

Question 26

Axons and dendrites of individual neurons, arranged in bundles and covered by connective tissue, make up ________.

Question 27

You might have been accidentally exposed to an insecticide while working in a citrus grove. What symptoms of poisoning would you watch for?

A) depression
B) Alzheimer's disease
C) muscle tremors
D) excessive urination

Question 28

Which neurotransmitter may function to regulate emotions and is involved in pathways that control complex movements?

A) dopamine
B) serotonin
C) norepinephrine
D) synapse

Question 29

________ is the name of the cell that wraps around the axon, forming the myelin sheath.

Question 30

________ is a progressive brain disease in which the dopamine-producing neurons in the movement control center of the brain die.

Question 31

A(n) ________, or afferent, neuron conducts information toward the brain and spinal cord.

Question 32

Your classmate does not have much muscle strength. Her doctor says she has an autoimmune disease, but you didn't quite catch the name the physician gave for the illness. Based on what you have learned, what do you think the diagnosis is?

A) Alzheimer's disease
B) schizophrenia
C) senility
D) myasthenia gravis

Question 33

Which neurotransmitter appears to be associated with an energizing "good" feeling and is essential in hunger, thirst, and sex drive?

A) dopamine
B) serotonin
C) norepinephrine
D) synapse

Question 34

Prior to their release, where are the special chemicals called neurotransmitters stored in a neuron?

A) axon
B) synaptic knob
C) dendrites
D) cell body

Question 35

________ is the name given to the motor neurons that carry information away from the brain or spinal cord.

Question 36

The neuron that releases neurotransmitters is known as ________, while the neuron that receives the neurotransmitters is knows as ________.

Question 37

The neuron requires a certain level of depolarization of its membrane in order to generate an action potential. This level of depolarization is known as the ________.

Question 38

________ are numerous short, branching projections from the neuron that create a huge surface for receiving signals from other cells.

Question 39

Immediately after an action potential occurs, the sodium channels close and cannot be reopened. What is this period called?

Question 40

Which of the following is a neurotransmitter that triggers a contraction of a voluntary muscle?

A) synapse
B) action potential
C) sodium
D) acetylcholine

Question 41

Compare and contrast the sensory neurons, motor neurons, and interneurons.

Question 42

If a drug had the side effect of destroying dopamine-producing neurons, what effect would this have on a person?

Question 43

What is the function of the myelin sheath in the nervous system?

Question 44

In the disease myasthenia gravis, the immune system attacks the receptors for the neurotransmitter acetylcholine. A drug is used to inhibit the enzyme acetylcholinesterase, which normally removes the neurotransmitter. This improves the condition of the patient. How does this work?

Question 45

Explain the anatomy of a typical neuron.

Question 46

________ involves an insufficient amount of several neurotransmitters, such as serotonin, dopamine, and norepinephrine, for extended periods of time.

Question 47

The enzyme that removes the neurotransmitter acetylcholine from synapses after it has been released is known as ________.

Question 48

What are some of the dangers associated with the use of organophosphate pesticides that might be of concern for humans? (Organophosphates inhibit acetylcholinesterase.) What are some ethical concerns related to their use?

Question 49

Tay-Sachs disease is a genetic disorder in which fat deposits build up in nerve cells of the brain, leading to a slow loss of function. Because this disease usually strikes children under 1 year of age, the symptoms are not immediately apparent. Think about the symptoms that this condition would cause. List some that you think are possible. What would be the inevitable end result as the disease progresses?

Question 50

Some nerves are myelinated, and others are not. Myelinated nerves send signals faster than unmyelinated neurons. Draw two neurons of equal length, and wrap segments of myelin along one. Be careful to leave spaces for the nodes of Ranvier. Now, measure the exposed axons of each, and total up the distance. Describe why the myelinated neurons send signals faster.

Question 51

Association neurons that are located between the sensory and motor neurons, where they integrate or interpret the sensory signals.

Question 52

Potassium ions are important in the resting membrane potential and the action potential of the nerve and to the contraction of muscle cells. The concentration gradient of potassium ions is critical to both. An excess of potassium outside a neuron or muscle cell would negate the concentration gradient. What would happen if the heart were injected with massive amounts of potassium? Explain your answer.

Question 53

________ is a neurotransmitter released at every neuromuscular junction (the junction of a motor neuron and a skeletal muscle cell), where it triggers contraction of voluntary (skeletal) muscles.

Question 54

The synaptic ________ is the narrow space between two neurons.