Deck 30: Nervous and Sensory Systems

Question 1

A strong stimulus produces

A)stronger action potentials.
B)more action potentials.
C)both more and stronger action potentials.
D)more nodes of Ranvier.

Answer 1

B

Question 2

The figure below illustrates how a neuron with a myelinated axon transmits signals.
What is happening in Region A of this figure?

A)An action potential is moving between two nodes of Ranvier.
B)Neurotransmitters are rapidly diffusing between two nodes of Ranvier.
C)An electric charge is moving rapidly between two nodes of Ranvier.
D)Myelin is carrying sodium ions between two nodes of Ranvier.

Answer 2

C

Question 3

Which of the following best describes the flow of signals in our nervous system?

A)from motor neurons to sensory neurons to interneurons
B)from sensory neurons to interneurons to motor neurons
C)from interneurons to sensory neurons to motor neurons
D)from sensory neurons to motor neurons to interneurons

Answer 3

B

Question 4

Which of the following is the pathway an action potential would travel in a neuron?

A)cell body to axon to dendrite
B)axon to dendrite to cell body
C)dendrite to axon to cell body
D)dendrite to cell body to axon

Question 5

Which of the following is most likely to be myelinated?

A)an interneuron
B)the axon between your spinal cord and your big toe
C)an axon that only exists within the spinal cord
D)a neuron in the thalamus

Question 6

Action potentials move faster in myelinated nerve fibers because

A)sodium ions can leap from node to node.
B)dendrites do not need to connect directly to axons.
C)sodium ions can pass through myelin faster than they do across the plasma membrane of a neuron.
D)action potentials leap from node to node.

Question 7

An action potential travels in only one direction, because

A)the nodes of Ranvier are open only at the site of the action potential.
B)only the sodium channels "downstream" are open.
C)only the sodium channels at the site of the action potential remain open.
D)sodium ions can move only between the nodes of Ranvier.

Question 8

Which of the following statements about axons is false?

A)They transmit self-sustaining signals.
B)They transmit signals in two directions.
C)They are a long extension of a neuron.
D)They have a terminus that transmits signals to other cells.

Question 9

How does the central nervous system recognize how important a particular stimulus is?

A)by the frequency at which the action potentials are created by the stimulus
B)by the overall strength of the action potential produced by the stimulus
C)by the number of neurotransmitters that reach the brain through the circulatory system
D)by the amount of hormone that the stimulus releases from endocrine glands

Question 10

A myelin sheath

A)stores sodium ions.
B)acts as an electrical conductor.
C)acts as an insulator.
D)contains action potentials.

Question 11

The branched receiving ends of a nerve cell are called

A)dendrites.
B)axons.
C)neurons.
D)synapses.

Question 12

Initially, when a neuron receives a stimulus,

A)sodium diffuses out of the neuron.
B)neurotransmitters are released from axon terminals.
C)sodium channels close.
D)sodium enters the neuron.

Question 13

Which of the following is an example of a reflex arc?

A)After reading all the possible answers to this question, you choose answer A.
B)The pupils of your eyes increase in diameter when you walk into a dark room.
C)A cell in your body releases insulin in response to the intake of food.
D)On a hot day, your body releases sweat. As the sweat evaporates, your body cools.

Question 14

Neurotransmitters carry a signal from a stimulated nerve cell to another nerve cell across a gap known as a

A)synaptic cleft.
B)target.
C)receptor.
D)cytokinin.

Question 15

If a stimulus is strong enough to reach a threshold level,

A)an action potential is shut down.
B)an action potential occurs.
C)sodium channels in the myelin open.
D)the resting potential is restored.

Question 16

A person with vitamin B deficiency often exhibits a "slow" nervous system. For example, their knee-jerk reflex is much slower than normal. Which of the following might explain why this is the case?

A)The neurons of people with vitamin B deficiency have more sodium channels in the plasma membranes of their neurons than normal.
B)People with a vitamin B deficiency produce less myelin than a normal person does.
C)Axons are slightly longer in a person with vitamin B deficiency, so the distance between transmitting and receiving cells is shorter.
D)People with vitamin B deficiencies produce weaker action potentials than normal people do.

Question 17

Axons transmit information in the form of

A)resting potentials.
B)sodium channels.
C)action potentials.
D)myelin sheaths.

Question 18

At resting potential, the overall charge of the plasma membrane is

A)positive because of the movement of myelin out of a neuron.
B)negative because of the sodium ions being pumped out of a neuron.
C)positive because sodium channels open in the axon but not in the cell body.
D)negative because sodium channels close in the dendrite but not in the axon.

Question 19

A reflex arc

A)has only sensory and interneurons.
B)is composed of three interneurons.
C)has a sensory neuron, an interneuron, and a motor neuron.
D)has an interneuron between two motor neurons.

Question 20

Although many people worry about their sodium intake from salty foods, it would be unwise to eliminate sodium from one's diet completely. Which of the following problems would occur if there were no sodium in the body?

A)The myelin sheath of the neurons would begin to break down.
B)Axons would be unable to create the action potential necessary for rapid signal movement.
C)The synapses between neurons and their adjacent cells would collapse.
D)The speed of the neuron's action potential would increase to a dangerously high level.

Question 21

The cerebrum has four major lobes. Which of the following is one of these?

A)parietal
B)cerebellum
C)thalamus
D)medulla oblongata

Question 22

Which area of our brain acts as a "traffic manager"?

A)the thalamus
B)the cerebral cortex
C)the pons
D)the cerebellum

Question 23

Botulism is a type of paralysis (inability to move muscles)caused by a specific type of bacteria. The bacteria release a toxin that prevents the release of acetylcholine (a neurotransmitter)from the neurons that form synapses with muscle cells. Why might botulism toxin cause paralysis?

A)Without acetylcholine, action potentials never get to muscle cells because they cannot move from one node of Ranvier to the next.
B)Since acetylcholine is responsible for establishing the concentration gradient of sodium ions, action potentials cannot form in the neurons of individuals with botulism.
C)If acetylcholine is not released, action potentials that stimulate muscle contraction cannot be transmitted across the synaptic cleft to muscle cells.
D)In the absence of acetylcholine, sensory neurons are unable to communicate with motor neurons so motor neurons never receive the signal to cause muscle contraction.

Question 24

The area of the brain that filters and sorts signals from the spinal cord also determines which signals require an action without awareness and which signals need to be sent to the conscious perception centers. This area of the brain is known as the

A)cerebrum.
B)pituitary gland.
C)thalamus.
D)cortex.

Question 25

The cerebral cortex of the human brain is much more highly and intricately folded than the same region in other animals. Why might this be the case?

A)The folds create more surface area for the production and release of the hormones that allow the human nervous system to interact with the endocrine system.
B)The folds are the remnants of the compression of the brain that occurs during childbirth.
C)The folds increase the surface area available for the complex thoughts and processing that occur in that region of the human brain.
D)Evolution has caused the brain to increase in size faster than the skull has increased in size. Folding allows our larger brain to more easily fit into our skulls.

Question 26

To best help it "sniff out" a fox, a hunting dog probably has a high concentration of

A)chemoreceptors in its nasal cavity.
B)mechanoreceptors in its ears.
C)proprioreceptors in its nasal cavity.
D)thermoreceptors in its front paws.

Question 27

Researchers have suggested a fifth taste in humans known as umami and attribute the taste to the compound glutamate. Which of the following would support the belief that umami is a real "taste"?

A)Identifying a chemoreceptor in the nasal cavity that glutamate can bind to.
B)The isolation of a sensory neuron that creates nerve impulses in response to pressure from glutamate.
C)Finding chemoreceptors in a taste bud that create nerve impulses in response to an interaction with glutamate.
D)Identification of glands in the oral cavity that release saliva in response to the presence of glutamate.

Question 28

The distance between an axon terminal and the receiving cell must be very small because

A)the plasma membranes of the two cells must be almost touching for action potentials to pass from one to the other.
B)neurons use the diffusion of neurotransmitters to transmit stimuli between cells and diffusion is only rapid over short distances.
C)the short distance creates a large surface area so that the receiving cell can receive a large number of neurotransmitters at once, ensuring rapid signal transmission.
D)the short distance allows sodium to be exchanged between the two cells, ensuring that the receiving cell has enough sodium to create an action potential.

Question 29

The brain has important interactions with the endocrine system. Which part of the brain directly stimulates the release of hormones from the pituitary gland?

A)hypothalamus
B)cerebrum
C)cerebellum
D)central cortex

Question 30

A drug that decreases your ability to taste and smell might inhibit the function of

A)photoreceptors.
B)thermoreceptors.
C)mechanoreceptors.
D)chemoreceptors.

Question 31

Our overall perception of food depends on

A)chemoreceptors.
B)photoreceptors.
C)mechanoreceptors.
D)all of the above

Question 32

After a signal has been transmitted to a receiving cell, neurotransmitters are rapidly removed from the synaptic cleft because

A)if even one neurotransmitter escapes from the synaptic cleft, it will produce action potentials in other neurons.
B)if neurotransmitters are not removed, they will enter the receiving cell and stimulate action potentials in organelle membranes.
C)neurotransmitters that remain in the synaptic cleft continue to bind to receptors in the receiving cell, potentially initiating new action potentials.
D)making neurotransmitters from scratch is energetically expensive so the cell must recycle them.

Question 33

Where would you expect to see an absence of neurotransmitters?

A)in a synapse
B)in a myelin sheath
C)in a synaptic cleft
D)in the terminus of an axon

Question 34

Which of the following is not one of the three major regions of the human brain?

A)medulla
B)forebrain
C)midbrain
D)hindbrain

Question 35

As you read this question, your eyes are moving to project the image of each word on your

A)pupil.
B)lens.
C)rods.
D)fovea.

Question 36

Which of the following would not be found in the retina of a horse?

A)rods
B)lenses
C)proprioceptors
D)pigments

Question 37

As you complete this exam, which part of the brain is helping you decide which answer is correct?

A)cerebellum
B)pons
C)thalamus
D)cerebral cortex

Question 38

The human skin has numerous sensory receptors that take in information about our environment, and these receptors are concentrated in areas where detailed information on touch is needed. Which of the following body areas is likely to have the smallest number of sensory receptors?

A)fingertips
B)face
C)buttocks
D)feet

Question 39

The largest, most visible part of the human brain is the

A)hippocampus.
B)cerebrum.
C)hypothalamus.
D)thalamus.

Question 40

A drug that inhibits the function of mechanoreceptors would affect your sense of

A)touch.
B)light.
C)individuality.
D)smell.

Question 41

The cerebrum has four major lobes, the parietal lobe, the frontal lobe, the temporal lobe, and the ____________________ lobe.

Question 42

Examine the figure below.

The path of the arrows in this figure indicates the movement of ____________________ through a neuron.

Question 43

A person who, as a result of a mutation, could not produce one of the pigment molecules found in cones

A)would have difficulty seeing some or all colors.
B)could not see black and white.
C)could see only at night and under low light conditions.
D)would not able to detect light of any color.

Question 44

Neurotransmitters are released into a synaptic cleft by the process of ____________________.

Question 45

In the eyes of animals that are primarily active at night, such as raccoons, the retina would

A)contain mostly rods.
B)not have pupils.
C)focus images.
D)lack a fovea.

Question 46

In vertebrates, special cells produce an insulating sheath of ____________________ that wraps around the axon of a neuron.

Question 47

Which of the following would most likely have compound eyes?

A)a spider
B)a housefly
C)an elephant
D)a squid

Question 48

Nodes of Ranvier are found only in ____________________ neurons.

Question 49

The eye is not like a camera in which of the following ways?

A)Both the eye and the camera can adjust their focus to account for how far away an object is located.
B)Both the eye and the camera have lenses that bend light waves.
C)Both the eye and the camera have mechanisms to control the amount of light that enters.
D)Both the eye and the camera focus by changing the distance between the lens and the surface that reacts to light.

Question 50

The brain and spinal cord make up the ____________________ nervous system.

Question 51

The ____________________ nervous system ferries signals to and from the central nervous system.

Question 52

As a whole, the nervous system converts stimuli into ____________________ input-action potentials that convey information about stimuli.

Question 53

Immediate levels of hearing loss can occur from

A)iPod use.
B)listening to traffic.
C)hearing a gun shot at close range.
D)attending a symphony in an enclosed concert hall.

Question 54

The center of the human retina has a region called the ____________________ where cones are most densely packed.

Question 55

The axons of many individual neurons may be bundled together to form communication pathways known as ____________________.

Question 56

The figure below illustrates the organ of Corti, a part of the cochlea in the human inner ear.
What labeled region of this figure of the organ of Corti is directly stimulated to vibrate in response to the air movements caused by sound?

A)Region A
B)Region B
C)Region C
D)Region D

Question 57

A signal-sending neuron releases a ____________________, a molecule that carries the signal across the synapse between nerve cells.

Question 58

The figure below depicts a human eye.
When focusing on an object that is far away, the structure indicated by the arrow in the figure above

A)becomes flatter.
B)becomes more spherical.
C)does not change.
D)decreases in diameter.

Question 59

The flow of ions across an axon's plasma membrane generates an electrical impulse known as the ____________________.

Question 60

When a signal causes sodium ions to flow into a neuron it becomes ____________________.

Question 61

One interneuron can send signals to the peripheral nervous system and the brain at the same time.

Question 62

The sound intensity in the front rows of a rock concert is approximately 110 decibels. A pair of earplugs reduces sound intensity by about 30 decibels. A person wearing earplugs who is seated in the front rows of a rock concert for 1 hour has sufficiently protected his or her ears from hearing damage.

Question 63

The position of our body is reported by mechanoreceptors called ____________________.

Question 64

The use of ear plugs in areas of loud sounds has been shown not to reduce the risk of hearing loss.

Question 65

A neurotransmitter can inhibit the formation of an action potential in a receiving cell.

Question 66

Action potentials and resting potentials are the same thing.

Question 67

A resting neuron is negatively charged inside relative to the outside.

Question 68

Compound eyes of insects use mechanoreceptors rather than photoreceptors.

Question 69

Neurotransmitters move from dendrites to cell bodies to axons.

Question 70

The cell indicated by the arrow in the figure below directly interacts with environmental stimuli.

Question 71

The hypothalamus contains neurons that release hormones in response to action potentials.

Question 72

Everyone who abuses drugs from an early age will become an addict.

Question 73

To respond to an incoming signal, such as your fingertip being burned by a candle's flame, the signal must be transmitted to the brain before your muscles can be told to respond and pull away.

Question 74

When the difference in charge across a neuron's cell membrane decreases the cell is depolarizing.

Question 75

In bright light, the openings in the pupils of our eyes become smaller.

Question 76

Sound intensity is measured in ____________________.

Question 77

Action potentials can transmit information rapidly but weaken as they move along a neuron.

Question 78

We perceive pressure waves in air as ____________________.