Deck 11: Functional Organization of Nervous Tissue

Question 1

The nervous system

A) monitors internal and external stimuli.
B) transmits information in the form of action potentials.
C) interprets or assesses information.
D) maintains homeostasis.
E) All of these choices are correct.

Answer 1

E

Question 2

Dendrites

A) are the input part of the neuron.
B) conduct action potentials away from the cell body.
C) are generally long and unbranched.
D) form synapses with the microglia.
E) contain the trigger zone.

Answer 2

A

Question 3

Which of the following is mismatched?

A) central nervous system - brain
B) autonomic nervous system - sympathetic and parasympathetic divisions
C) peripheral nervous system - spinal nerves
D) somatic nervous system - sensory division of PNS
E) peripheral nervous system - sensory and motor divisions

Answer 3

D

Question 4

Cell bodies of the peripheral nervous system are located in

A) ganglia.
B) Schwann cells.
C) the motor division.
D) the sensory division.
E) nerves.

Question 5

The junction of a neuron with another cell is a/an

A) synapse.
B) ganglion.
C) receptor.
D) effector.

Question 6

The motor (efferent) division of the peripheral nervous system

A) is a division of the CNS.
B) regulates the digestion of food.
C) transmits impulses from the CNS to skeletal muscle.
D) has nerve cell bodies located in ganglia near the spinal cord and brain.
E) detects a stimulus.

Question 7

The sensory (afferent) division of the peripheral nervous system

A) transmits action potentials to sensory organs.
B) conveys action potentials to the CNS.
C) stimulates glands to release hormones.
D) stimulates muscle contractions.
E) does not involve sensory receptors.

Question 8

Which of the following is responsible for problem-solving skills?

A) central nervous system
B) peripheral nervous system
C) somatic nervous system
D) autonomic nervous system
E) None of these choices is correct.

Question 9

There are _____ pairs of cranial nerves and _____ pairs of spinal nerves.

A) 10; 30
B) 31; 12
C) 12; 31
D) 30; 10
E) 12; 32

Question 10

Synaptic vesicles contain neurotransmitters and are present in the

A) dendrites.
B) cell body.
C) axolemma.
D) presynaptic terminals.
E) trigger zone.

Question 11

The central nervous system includes the

A) ganglia.
B) spinal cord.
C) spinal nerves.
D) cranial nerves.
E) sensory receptors.

Question 12

Digestion of food is regulated by the

A) sensory division.
B) sympathetic division of the ANS.
C) parasympathetic division of the ANS.
D) somatic nervous system.
E) None of these choices are correct.

Question 13

Axons contain

A) the trigger zone.
B) foot processes.
C) Nissl bodies.
D) the soma.
E) the rough endoplasmic reticulum.

Question 14

Nissl bodies are

A) part of a dendrite.
B) also called gemmules.
C) lipid droplets.
D) areas of rough endoplasmic reticulum.
E) part of the Golgi apparatus.

Question 15

The autonomic nervous system

A) stimulates skeletal muscle contractions.
B) has two sets of neurons in a series.
C) is involved in problem solving.
D) is under voluntary control.
E) does not include the central nervous system.

Question 16

Protein synthesis in neurons occurs in

A) axons.
B) dendrites.
C) cell bodies or soma.
D) terminal boutons.
E) node of Ranvier.

Question 17

The enteric nervous system consists of plexuses within the walls of the

A) brain.
B) spinal cord.
C) digestive tract.
D) urinary bladder.

Question 18

The central nervous system

A) is the site for processing information.
B) initiates visual and auditory stimuli.
C) consists of 43 pairs of nerves.
D) is totally involuntary.
E) does not interact with the peripheral nervous system.

Question 19

The peripheral nervous system includes the

A) brain.
B) spinal cord.
C) cranial nerves.
D) blood-brain barrier.
E) cerebellum.

Question 20

Axons

A) contain the nucleus.
B) are numerous extensions from each neuron.
C) do not have a trigger zone.
D) have a distal portion that branches to form the presynaptic terminals.
E) do not have a resting membrane potential.

Question 21

Which of the following is NOT true of reactive astrocytosis?

A) injury site is blocked off
B) scars limit regeneration
C) causes the spread of inflammation
D) reduces injury to surrounding tissue

Question 22

Neurons in the skin that are responsible for detecting pain are

A) apolar.
B) pseudo-unipolar.
C) bipolar.
D) multipolar.

Question 23

The motor neurons responsible for making a fist are

A) tripolar.
B) bipolar.
C) multipolar.
D) pseudo-unipolar.
E) None of these choices are correct.

Question 24

A neuroglial cell that is a major component of the blood-brain barrier is the

A) astrocyte.
B) microglial cell.
C) oligodendrocyte.
D) ependymal cell.
E) macrophage.

Question 25

Which of the following statements regarding neuroglia is false?

A) Neuroglia serve as the major supporting tissue in the CNS.
B) Neuroglia form part of the blood-brain barrier.
C) Neuroglia produce action potentials for skeletal muscles.
D) Neuroglia form myelin sheaths around some axons.
E) Neuroglia produce cerebrospinal fluid.

Question 26

A neuron that conducts pain sensations to the central nervous system would be classified as a(n)

A) motor neuron.
B) sensory or afferent neuron.
C) efferent neuron.
D) association neuron.
E) interneuron.

Question 27

What type of neuroglial cells provide support and nutrition to sensory ganglia in the PNS?

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

Question 28

Multiple sclerosis is a neurological disorder in which myelin sheaths in the CNS are destroyed. Which of the following neuroglial cells is being damaged in multiple sclerosis?

A) astrocyte
B) microglial cell
C) oligodendrocyte
D) ependymal cell
E) Schwann cells

Question 29

Schwann cells differ from oligodendrocytes in which of the following ways?

A) Schwann cells form myelin; oligodendrocytes do not.
B) Oligodendrocytes are only found in the PNS; Schwann cells are only found in the CNS.
C) Schwann cells form sheaths around several axons, while oligodendrocytes form sheaths around only one axon.
D) Schwann cells form a myelin sheath around a portion of only one axon, while oligodendrocytes can surround portions of several axons.
E) None of these choices are true differences.

Question 30

Which of the following is mismatched?

A) microglia - provide support for the neuron cell body
B) astrocytes - blood-brain barrier
C) oligodendrocytes - form myelin sheaths
D) ependymal cells - produce cerebrospinal fluid
E) ependymal cells - choroid plexus

Question 31

Action potentials are conducted more rapidly when transmission is

A) from node to node on a myelinated axon.
B) on a small diameter axon.
C) on an unmyelinated axon.
D) from internode to internode.
E) from internode to node on a myelinated axon.

Question 32

The blood-brain barrier

A) permits passage of foreign substances from the blood to the neurons.
B) prohibits the transport of amino acids and glucose to the neurons.
C) prohibits the removal of waste materials from the neurons.
D) protects neurons from toxic substances in the blood.
E) does not prevent fluctuations in the composition of the blood from affecting the functions of the brain.

Question 33

Which of the following is NOT a neuroglia of the CNS?

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

Question 34

Microglia

A) are part of the blood-brain barrier.
B) are phagocytic cells in the CNS.
C) produce cerebrospinal fluid.
D) form myelin sheaths.
E) are part of the choroid plexus.

Question 35

Which of the following is NOT true about astrocytes?

A) They can wall off an injury site to prevent spread of inflammation.
B) They can prevent toxic substances from entering brain tissue.
C) They can release chemicals that promote formation of synapses.
D) They can aid in the regeneration of injured neurons.

Question 36

A neuron within the central nervous system that carries action potentials from one neuron to another is called a(n)____________.

A) motor neuron
B) sensory neuron
C) afferent neuron
D) efferent neuron
E) interneuron

Question 37

Neurons that have a single axon and a single dendrite are

A) tripolar.
B) bipolar.
C) multipolar.
D) pseudo-unipolar.

Question 38

Overproduction of cerebrospinal fluid could be the result of overactivity of the

A) astrocytes.
B) microglial cells.
C) oligodendrocytes.
D) macrophages.
E) ependymal cells.

Question 39

Which of the following is true?

A) Unmyelinated axons rest in invaginations of Schwann cells or oligodendrocytes..
B) Myelination will not influence the speed of conduction of action potentials.
C) The myelin sheath inhibits the flow of electrical charges at nodes.
D) The myelin sheath is a protein wrapping.
E) The myelin sheath does not electrically insulate the axons from one another.

Question 40

Gaps or interruptions in the myelin sheath are called

A) internodes.
B) tight junctions.
C) neurofilaments.
D) nodes of Ranvier.
E) gap junctions.

Question 41

A local potential

A) does not occur until threshold.
B) transmits information from one cell to another.
C) might be a depolarization event but cannot be a hyperpolarization event.
D) increases or decreases in direct proportion to the stimulus strength.
E) does not alter resting membrane potential.

Question 42

For the resting membrane potential, increasing the sodium ion concentration in the ECF results in

A) hyperpolarization.
B) depolarization.
C) hypopolarization.
D) little change in membrane potential.
E) There is not enough information to determine the results.

Question 43

In hyperpolarization

A) K+ ions tend to diffuse out of the cell.
B) the plasma membrane's permeability to K+ decreases.
C) the resting membrane potential moves closer to zero.
D) Na+ ions enter the cell in large numbers.
E) the resting membrane potential becomes more positive.

Question 44

Gray matter on the surface of the brain is/are called

A) the cortex.
B) nuclei.
C) ganglia.
D) tracts.

Question 45

Which of the following events will lead to depolarization?

A) an increase in K+ ions in the extracellular fluid
B) a decrease in K+ ions in the extracellular fluid
C) an increase in the rate of diffusion of K+ ions from cells
D) an increase in Na+ ions in the extracellular fluid
E) None of these events would cause depolarization.

Question 46

Mr. Miller has been hospitalized for the flu. The flu virus increases membrane permeability to potassium. You would expect his cells to

A) depolarize.
B) repolarize.
C) isopolarize.
D) hyperpolarize.
E) hypopolarize.

Question 47

Gray matter consists of bundles of myelinated axons.

Question 48

White matter is composed of

A) ganglial sheaths.
B) bundles of myelinated axons.
C) collections of nerve cell bodies.
D) bundles containing both myelinated axons and nerve cell bodies.
E) collections of unmyelinated axons.

Question 49

Which of the following statements accurately describe events that occur as a result of a local potential reaching threshold?

A) Activation gates of Na+ ion channels begin to close.
B) Inactivation gates of Na+ ion channels begin to open.
C) A positive feedback cycle develops in which depolarization causes activation gates of Na+ ion channels to open.
D) K+ ion channels begin to close.
E) Inactivation gates of Na+ ion channels begin to open and a positive feedback cycle develops in which depolarization causes activation gates of Na+ ion channels to open.

Question 50

Clusters of gray matter deep within the brain are called

A) cortices.
B) nerves.
C) ganglia.
D) nuclei.

Question 51

The plasma membrane of a neuron is more permeable to potassium ions because

A) of its positive electrical charge.
B) there are more leak ion channels for K+ than Na+.
C) protein molecules cannot exit through the cell membrane.
D) calcium ions block Na+ and Cl- channels.
E) there are more leak ion channels for Na+ than K+.

Question 52

If the charge difference across the plasma membrane is decreased,

A) the potential difference across the plasma membrane does not change.
B) the membrane potential is more positive.
C) the change is called hyperpolarization.
D) negative proteins can leave the cell.
E) the membrane potential is more negative.

Question 53

A change in resting membrane potential confined to a small area is called a(n)

A) local potential.
B) action potential.
C) summated potential.
D) after potential.
E) resting membrane potential.

Question 54

Voltage-gated sodium channels are sensitive to changes in the extracellular concentration of

A) potassium ions.
B) proteins.
C) sodium ions.
D) chloride ions.
E) calcium ions.

Question 55

If you cut bundles of axons and their myelin sheaths in the PNS, you cut

A) ganglia.
B) nuclei.
C) nerves.
D) gray matter.
E) nerve tracts.

Question 56

Gray matter has little myelination, whereas white matter has abundant myelination.

Question 57

Which of the following situations will lead to hyperpolarization?

A) increase the permeability of the plasma membrane to Na+ ions
B) decrease the permeability of the plasma membrane to K+ ions
C) decrease the permeability of the plasma membrane to chloride ions
D) any positive ion entering the cell
E) None of these situations will lead to hyperpolarization.

Question 58

Which of the following is true?

A) The resting plasma membrane is more permeable to Na+ than K+.
B) The resting membrane potential never reaches an equilibrium point.
C) The resting membrane potential is proportional to the tendency for K+ to diffuse out of the cell.
D) Negatively charged Cl- ions are attracted by negative charges in the cell.
E) The purpose of the sodium-potassium exchange pump is to create an equilibrium of ion concentrations.

Question 59

A change in the resting membrane potential has the following characteristics (non-propagated, graded, can summate). This type of change can

A) be a local potential.
B) be an action potential.
C) be a consequence of an increase in the permeability to Na+.
D) result in repolarization.
E) be a local potential and a consequence of an increase in the permeability to Na+.

Question 60

Which of the following situations occurs in electrically excitable cells?

A) When Na+ ion channels open, K+ ion channels close.
B) The sodium-potassium exchange pump moves sodium into the cell.
C) Depolarization causes voltage-gated sodium ion channels to open.
D) Ligand-gated sodium ion channels are opened by high extracellular calcium levels.
E) Proteins tend to diffuse out of the cell.

Question 61

When repolarization of a neuron is complete, the

A) neuron dies.
B) neuron regenerates.
C) cell no longer has a potential difference across its membrane.
D) original polarity of the neuron is restored.
E) neuron is no longer excitable.

Question 62

A stimulus that results in a local potential that does not reach threshold is called a

A) threshold stimulus.
B) maximal stimulus.
C) subthreshold stimulus.
D) supramaximal stimulus.
E) local stimulus.

Question 63

During depolarization of the plasma membrane,

A) sodium ions move rapidly into the cell.
B) potassium ions move rapidly out of the cell.
C) membrane permeability to sodium ions decreases.
D) the outside of the cell becomes positively charged relative to the inside.
E) sodium ions move rapidly out of the cell.

Question 64

During the absolute refractory period, the cell

A) generates many local potentials.
B) is insensitive to further stimulation.
C) responds to even weak stimuli.
D) reverses the direction of the action potential.
E) is very sensitive.

Question 65

If the ECF around a nerve cell is replaced with an isotonic saline solution that contains potassium ions and other solutes at concentrations very close to the ECF concentrations of a normal cell, the result is

A) no resting membrane potential.
B) hyperpolarized membrane.
C) depolarized membrane.
D) a resting membrane potential close to its normal value.
E) None of these choices is correct.

Question 66

As the strength of a stimulus is increased, the

A) amplitude of the action potential increases.
B) duration of the action potential increases.
C) frequency of occurrence of action potentials increases.
D) resonance of action potentials increases.
E) height of the action potentials increases.

Question 67

Each voltage-gated Na+ ion channel has two voltage sensitive gates: an activation gate and an inactivation gate. Which of the following would occur during depolarization?

A) Activation gates are open; inactivation gates are closed.
B) Activation gates are closed; inactivation gates are open.
C) Both activation and inactivation gates are open.
D) Both activation and inactivation gates are closed.
E) None of these events occurs during depolarization.

Question 68

Continuous conduction of an action potential means that

A) once one action potential is created, it moves down the axon.
B) the whole axon depolarizes at the same time.
C) one action potential stimulates the production of a new action potential at the adjacent site.
D) an action potential is conducted from one node of Ranvier to the next node.

Question 69

The absolute refractory period assures

A) prolonged depolarization during the action potential.
B) completion of repolarization before another action potential.
C) that no after-potential occurs.
D) reversal of the direction of propagation of the action potential.
E) that the stimulus is strong enough to elicit a response.

Question 70

In some cells, an afterpotential occurs because

A) the sodium ions continue to enter the cell after depolarization is finished.
B) there is prolonged, elevated permeability to potassium during repolarization.
C) the sodium-potassium pump is actively exchanging ions across the membrane.
D) the extracellular Na+ ion concentration is reduced.
E) the permeability to sodium continues longer than necessary.

Question 71

Which of the following events is NOT a characteristic of an action potential?

A) The plasma membrane becomes highly permeable to sodium ions and depolarization results.
B) As sodium ions enter, the inside of the plasma membrane becomes more negative.
C) At the peak of depolarization, sodium channels begin to close and potassium channels open.
D) In repolarization, potassium ions flow out of the cell.
E) Action potentials occur according to the all-or-none principle.

Question 72

Depolarization of the nerve cell membrane occurs when there is a rapid influx (inflow) of

A) potassium ions.
B) chloride ions.
C) calcium ions.
D) sodium ions.
E) proteins.

Question 73

Which of the following statements regarding voltage-gated K+ channels is true?

A) These channels have only one gate.
B) These channels open more slowly than Na+ channels.
C) Once open, these channels remain open until repolarization is complete.
D) These channels are specific for potassium.
E) All of these statements are true.

Question 74

The absolute refractory period ends when

A) inactivation gates of voltage-gated Na+ ion channels reopen.
B) activation gates of voltage-gates Na+ ion channels reopen.
C) the sodium-potassium exchange pump stops.
D) voltage-gated K+ channels open.
E) None of these choices is correct.

Question 75

An action potential

A) occurs when the local potential reaches threshold level.
B) propagates across the plasma membrane in a decremental fashion.
C) has no repolarization phase.
D) is an example of negative feedback.
E) cannot transmit information.

Question 76

Saltatory conduction of an action potential means that

A) once one action potential is created, it moves down the axon.
B) the whole axon depolarizes at the same time.
C) one action potential stimulates the production of a new action potential at the adjacent site.
D) an action potential is conducted from one node of Ranvier to the next node.

Question 77

A stimulus either causes an action potential or it doesn't. This is called

A) an all-or-none response.
B) a graded response.
C) a latent period response.
D) a relative refractory response.
E) a local response.

Question 78

The strength of a stimulus is communicated through

A) changes in the magnitude of the action potential.
B) the frequency of the action potentials.
C) the length of time action potentials are produced.
D) both the frequency and the length of time action potentials are produced.

Question 79

The speed of an action potential depends upon

A) whether an axon is myelinated or not myelinated.
B) thickness of the myelin sheath.
C) the diameter of the axon.
D) All of the choices are correct.

Question 80

The opening of more and more Na+ ion channels during depolarization

A) is the result of the sodium-potassium exchange pump.
B) is an example of a positive feedback cycle.
C) is possible only if K+ channels remain closed.
D) is the cause of the afterpotential.
E) is an example of a negative feedback cycle.