Deck 11: Fundamentals of the Nervous System and Nervous Tissue

Question 1

Some nerve fibers of the peripheral nervous system have the ability to regenerate after damage has occurred. Which of the following cells is most responsible for aiding in this regulation?

A) Schwann cells
B) astrocytes
C) oligodendrocytes
D) satellite cells

Answer 1

A

Question 2

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system.

Answer 2

True

Question 3

The action potential is caused by permeability changes in the plasma membrane.

Answer 3

True

Question 4

It is important for newly developed neurons to form synapses with other neurons. Which cells are most responsible for guiding the formation of these particular junctions?

A) microglial cells
B) Schwann cells
C) satellite cells
D) astrocytes

Question 5

Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

A) sensory (afferent) division
B) somatic nervous system
C) sympathetic division
D) parasympathetic division

Question 6

Meningitis can be caused by infection of the central nervous system by bacteria. Which cells would be most responsible for removing the infection?

A) microglia
B) satellite cells
C) oligodendrocytes
D) Schwann cells

Question 7

Strong stimuli cause the amplitude of action potentials generated to increase.

Question 8

A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane.

Question 9

During depolarization, the inside of the neuron's membrane becomes less negative.

Question 10

Cranial nerve II, the optic nerve sends nerve impulses to the brain carrying information about the things we see. These nerve fibers most likely belong to which division of the nervous system?

A) sensory (afferent) division
B) somatic nervous system
C) sympathetic division
D) parasympathetic division

Question 11

The peripheral nervous system is divided into afferent and efferent divisions.

Question 12

Axon diameter and degree of myelination determine nerve impulse conduction velocity.

Question 13

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier.

Question 14

Enkephalins and endorphins are peptides that act like morphine.

Question 15

Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

A) sensory (afferent) division
B) somatic nervous system
C) sympathetic division
D) parasympathetic division

Question 16

The concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for this?

A) astrocytes
B) satellite cells
C) Schwann cells
D) oligodendrocytes

Question 17

Unipolar neurons have axons structurally divided into peripheral and central processes.

Question 18

Reflexes are rapid, automatic responses to stimuli that will produce the same effect every time.

Question 19

A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons.

Question 20

Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

A) sensory (afferent) division
B) somatic nervous system
C) sympathetic division
D) parasympathetic division

Question 21

If a postsynaptic neuron is stimulated to threshold by spatial summation this implies that .

A) the postsynaptic cell has many synapses with many presynaptic neurons
B) the postsynaptic cell has many voltage gated ion channels
C) the postsynaptic cell has a lower than normal threshold
D) the postsynaptic cell is slow to repolarize

Question 22

Which of the following is NOT a function of dendrites?

A) produce short-distance signals called graded potentials
B) generate nerve impulses and transmit them away from the cell body
C) provide enormous surface area for receiving signals from other neurons
D) convey incoming messages toward the cell body

Question 23

An action potential is regarded as an example of a positive feedback. Which of the following examples below best illustrates the positive feedback aspect of an action potential?

A) Potassium permeability is about 25 times greater than sodium ions.
B) Voltage gated potassium ion channels open slowly and remain open long enough to cause hyperpolarization.
C) A threshold stimulus will cause the opening of voltage gated sodium ion channels that will cause further depolarizing stimulus. This stimulus will open still more voltage gated sodium ion channels.
D) The sodium potassium pump consistently moves ions as long as ATP is available, and regardless of membrane potential changes.

Question 24

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?

A) gamma aminobutyric acid
B) cholinesterase
C) norepinephrine
D) acetylcholine

Question 25

These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid.

A) ependymal cells
B) astrocytes
C) Schwann cells
D) oligodendrocytes

Question 26

During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that _ _.

A) the membrane is now impermeable to all ions
B) the sodium potassium pump will stop working during relative refractory
C) the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane
D) the inactivation gates on voltage gated sodium ion channels are closed

Question 27

What does the central nervous system use to determine the strength of a stimulus?

A) type of stimulus receptor
B) frequency of action potentials
C) origin of the stimulus
D) size of action potentials

Question 28

Which of the choices below describes the ANS?

A) motor fibers that conduct nerve impulses from the CNS to skeletal muscles
B) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS
C) sensory and motor neurons that supply the digestive tract
D) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

Question 29

When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the postsynaptic cell?

A) opening of chemically gated sodium channels
B) hyperpolarization of the postsynaptic cell membrane
C) depolarization of the postsynaptic cell membrane
D) influx of positively charged ions into the postsynaptic cell

Question 30

When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the postsynaptic cell?

A) Chemically gated sodium channels will open.
B) Chemically gated sodium channels will be closed.
C) Chemically gated potassium channels will open.
D) Chemically gated chloride channels will open.

Question 31

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the .

A) absolute refractory period
B) resting period
C) depolarization
D) repolarization

Question 32

Which of the following describes the nervous system integrative function?

A) analyzes sensory information, stores information, makes decisions
B) responds to stimuli by gland secretion or muscle contraction
C) senses changes in the environment

Question 33

Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensive network of rough endoplasmic reticulum and many clusters of ribosomes. These cellular features indicate all of the following EXCEPT .

A) neurons must meet a high demand for ATP
B) neurons produce many proteins
C) neurons have stable, relatively unchanging internal environments
D) neurons have a relatively high consumption of oxygen

Question 34

Bipolar neurons are commonly _.

A) motor neurons
B) found in ganglia
C) called neuroglial cells
D) found in the retina of the eye

Question 35

Which of the following is NOT a characteristic of neurons?

A) They conduct impulses.
B) They have extreme longevity.
C) They have an exceptionally high metabolic rate.
D) They are mitotic.

Question 36

The depolarization phase of an action potential is punctuated by the closing of inactivation gates in the voltage gated sodium ion channels. All of the following are consequences of this inactivation except one. Choose the statement below that is not a consequence of the closing of inactivating gates.

A) This allows for the one way transmission of action potential down the axon.
B) This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell.
C) This limits the frequency of action potentials down the axon.
D) This stops the depolarization of the axon membrane.

Question 37

The effect of acetylcholine can be stimulating or inhibiting. Which of the following gives the best explanation for why this is so?

A) Acetylcholine has a "dose effect." Larger doses are stimulating while small doses inhibit.
B) Postsynaptic cells have a dynamic and changing metabolism and respond differently at different times.
C) Acetylcholine has many different forms.
D) Different postsynaptic cells will have different receptors.

Question 38

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?

A) ligand-gated channel
B) leakage channel
C) voltage-gated channel
D) mechanically-gated channel

Question 39

Loss of function in the enzyme acetylcholine esterase would result in which of the following?

A) inability to release acetylcholine
B) inability to destroy and remove acetylcholine from the synaptic cleft
C) amplify or enhance the effect of ACh
D) stimulation of the production of acetylcholine

Question 40

If a postsynaptic cell is stimulated to threshold by temporal summation this implies that .

A) the presynaptic neuron is sending frequent IPSP
B) a presynaptic neuron is sending frequent EPSP
C) the postsynaptic cell is sending frequent action potential
D) the postsynaptic cell can be influenced by only one presynaptic cell

Question 41

Which of the following correctly describes a graded potential?

A) It has a depolarization, repolarization, and hyperpolarization phase.
B) It can have amplitudes of various sizes.
C) It travels long distances.
D) It is initiated by voltage changes in the membrane.

Question 42

Which of the following is NOT a function of the autonomic nervous system?

A) innervation of skeletal muscle
B) innervation of glands
C) innervation of smooth muscle of the digestive tract
D) innervation of cardiac muscle

Question 43

A neuron that has as its primary function the job of connecting other neurons is called a(n) .

A) interneuron
B) glial cell
C) efferent neuron
D) afferent neuron

Question 44

Which of the following is true about the movement of ions across excitable living membranes?

A) Ions always move actively across membranes through leakage channels.
B) Sodium gates in the membrane can open in response to electrical potential changes.
C) Ions always move passively across membranes.
D) Ions always move from an area of higher concentration to an area of lower concentration.

Question 45

Which of the following neurotransmitters is the principal inhibitory neurotransmitter of the spinal cord?

A) serotonin
B) glycine
C) endorphin
D) acetylcholine

Question 46

A second nerve impulse cannot be generated until .

A) the Na ions have been pumped back into the cell
B) proteins have been resynthesized
C) the membrane potential has been reestablished
D) all sodium gates are closed

Question 47

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?

A) Sodium gates will open first, then close as potassium gates open.
B) Specific sodium gates will open.
C) A single type of channel will open, permitting simultaneous flow of sodium and potassium.
D) Specific potassium gates will open.

Question 48

Collections of nerve cell bodies outside the central nervous system are called .

A) nuclei
B) ganglia
C) nerves
D) tracts

Question 49

The interior surface of a neuron's plasma membrane at resting membrane potential will have a .

A) positive charge and contains less sodium than outside of the cell
B) negative charge and contains more sodium than outside of the cell
C) negative charge and contains less sodium than outside of the cell
D) positive charge and contains more sodium than outside of the cell

Question 50

Schwann cells are functionally similar to _.

A) oligodendrocytes
B) ependymal cells
C) astrocytes
D) microglia

Question 51

Saltatory conduction is made possible by _ .

A) large nerve fibers
B) the myelin sheath
C) erratic transmission of nerve impulses
D) diphasic impulses

Question 52

Which of the following is false or incorrect?

A) An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold.
B) An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane.
C) A nerve impulse occurs if the excitatory and inhibitory effects are equal.

Question 53

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) _ .

A) generator potential
B) excitatory potential
C) action potential
D) postsynaptic potential

Question 54

Which of the following is NOT a chemical class of neurotransmitters?

A) nucleic acid
B) ATP and other purines
C) biogenic amine
D) amino acid

Question 55

Immediately after an action potential has peaked, which of the following channels will open?

A) voltage-gated calcium channels
B) voltage-gated sodium channels
C) voltage-gated potassium channels
D) chemically-gated chloride channels

Question 56

The term central nervous system refers to the .

A) somatic nerves
B) sensory (afferent) nerves
C) spinal nerves
D) brain and spinal cord

Question 57

Select the correct statement regarding chemical synapses.

A) Cells with gap junctions use chemical synapses.
B) The release of neurotransmitter molecules gives cells the property of being electrically coupled.
C) The synaptic cleft uses the action potential to transmit a chemical signal to the postsynaptic cell.
D) Neurotransmitter receptors are located on the axons terminals of cells.

Question 58

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon, .

A) the impulse would move to the axon terminal only, and the muscle contraction would occur
B) the impulse would spread bidirectionally
C) muscle contraction would occur
D) the impulse would move to the axon terminal only

Question 59

An inhibitory postsynaptic potential (IPSP) is associated with .

A) opening of voltage-regulated channels
B) lowering the threshold for an action potential to occur
C) hyperpolarization
D) a change in sodium ion permeability

Question 60

Which of the following is NOT true of graded potentials?

A) They can be called postsynaptic potentials.
B) They increase amplitude as they move away from the stimulus point.
C) They are short-lived.
D) They can form on receptor endings.

Question 61

The part of the nervous system that conducts impulses from the CNS to the skeletal muscles is the
nervous system.

Question 62

What symptoms would a nurse focus on in his or her care of a patient with multiple sclerosis?

Question 63

Neuroglia found in the CNS that change the permeability of capillaries in the brain by binding to and surrounding these blood vessels are called .

Question 64

What mechanism is responsible for axonal transport?

Question 65

When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane than would result from a single EPSP; this event is called _ summation.

Question 66

What is the difference between a direct acting neurotransmitter and an indirect acting neurotransmitter?

Question 67

What is the role of microglial cells and why are they so important in the CNS?

Question 68

Which group of neurotransmitters play a role in emotional behavior and help regulate the biological clock?

Question 69

Because all action potentials are alike, how does the brain separate situations that require immediate attention from ordinary "positional" reports?

Question 70

What function is served by the increased axon diameter at the nodes of Ranvier?

Question 71

Which of the following describes the excitatory postsynaptic potential?

A) short distance depolarization
B) opens K+ or Cl- channels
C) moves membrane potential away from threshold
D) short distance hyperpolarization

Question 72

At the biochemical level, what is the explanation of the hyperpolarization phase at the conclusion of the action potential?

Question 73

A patient is admitted to the hospital with exacerbation of multiple sclerosis (MS). She asks the nurse, "Why did this have to happen to me again? I was doing so well." Explain why some forms of MS are characterized by periods of remission and exacerbation.

Question 74

A heroin addict was brought into the emergency room. The addict's friend asks the emergency room physician why heroin and morphine are such addictive drugs. How does the physician respond?

Question 75

Define synaptic delay.

Question 76

What are the basic divisions of the peripheral nervous system?

Question 77

The synapse more common in embryonic nervous tissue than in adults is the _ .

Question 78

Imagine a neuron that has several hundred axonal knobs impinging on it. The majority of these axonal knobs are shown to be "firing." However, the neuron in question does not transmit an impulse. Give a valid explanation of why this could occur.

Question 79

When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called _ processing.

Question 80

Multiple sclerosis (MS) is a disease in which the myelin sheaths are destroyed. What process does this interfere with and what would be the consequence?