Question 1

Motor neurons that carry information away from the brain or spinal cord are known as ________ neurons.

Accepted Answer

The answer of Motor neurons that carry information away from...

Question 2

The ________ can be defined as the specific value a membrane depolarization reaches to begin an action potential.

Accepted Answer

The answer of The ________ can be defined as the...

Question 3

________ refers to the jumping of a nerve impulse from one node of Ranvier to the next.

Accepted Answer

The answer of ________ refers to the jumping of a...

Question 4

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

Accepted Answer

The answer of During an action potential,the ________ ions rush...

Question 5

Ouabain is a chemical used on poison arrows in Africa.It works by inhibiting the Na+/K+ pump.What effect would this have on an action potential?

Accepted Answer

The Na+/K+ pump maintains ion gradients across the cell membrane, but it does not directly cause action potentials. Action potentials are generated by the opening of voltage-gated ion channels, not by the Na+/K+ pump.

Question 6

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

Accepted Answer

The answer of ________ is a progressive disorder in which...

Question 7

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

Accepted Answer

The answer of Immediately after an action potential occurs,the sodium...

Question 8

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

Accepted Answer

The answer of A(n)________,or sensory neuron,conducts information toward the brain...

Question 9

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

Accepted Answer

The answer of ________ are numerous short,branching projections from the...

Question 10

Axons and dendrites,or both,arranged in bundles and covered by connective tissue are ________.

Accepted Answer

The answer of Axons and dendrites,or both,arranged in bundles and...

Question 11

A(n)________ synaptic neuron releases neurotransmitters that act on the ________ synaptic neuron to start an action potential.

Accepted Answer

The answer of A(n)________ synaptic neuron releases neurotransmitters that act...

Question 12

The enzyme ________ removes the neurotransmitter acetylcholine from synapses after it has been released.

Accepted Answer

The answer of The enzyme ________ removes the neurotransmitter acetylcholine...

Question 13

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 impact the development of the nervous system.What could be affected?

Accepted Answer

Lipids are required by glial cells to produce myelin, which insulates and protects nerve fibers. Without enough lipids, the myelin sheath may not develop properly, leading to problems with nerve conduction and communication. Therefore, a low-fat diet could negatively impact the development of the nervous system. Options B, C, and D are not accurate because fats do not play a direct role in generating energy or neurotransmitters, or in generating action potentials.

Question 14

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

Accepted Answer

A lack of serotonin is associated with depression, so raising serotonin levels with prescription drugs like Prozac can act as an antidepressant.

Question 15

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

Accepted Answer

Sensory neurons are responsible for transmitting information from sensory receptors to the central nervous system (brain and spinal cord), allowing us to perceive and interpret sensations such as touch, pain, temperature, and pressure. In leprosy, these neurons are damaged, leading to a loss of sensation in the affected area. As a result, the person may not feel injuries or infections in their feet, which can lead to further complications.

Question 16

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?

Accepted Answer

Motor neurons are responsible for transmitting signals from the nervous system to the skeletal muscles for movement. When motor neurons are affected, the skeletal muscles lose their signal to contract and thus undergo atrophy or shrinkage. This is observed in Lou Gehrig's disease or ALS (amyotrophic lateral sclerosis), where motor neurons in the brain and spinal cord degenerate, leading to progressive muscle weakness and wasting.

Question 17

The synaptic ________ is the narrow space between two neurons.

Accepted Answer

The answer of The synaptic ________ is the narrow space...

Question 18

________ form the myelin sheath,which wraps around the axon,to insulate against short-circuiting between neurons.

Accepted Answer

The answer of ________ form the myelin sheath,which wraps around...

Question 19

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

Accepted Answer

The answer of ________ involves an insufficient amount of several...

Question 20

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?

Accepted Answer

Novocain inhibits the opening of sodium channels. Sodium channels are responsible for depolarizing the membrane potential and initiating an action potential. If the opening of sodium channels is inhibited, more stimulation will be needed to reach the threshold for an action potential to be initiated. Therefore, the threshold for a sensory neuron will increase with the use of Novocain.

Quiz 7: Neurons: the Matter of the Mind