Deck 11: Neural Tissue

Question 1

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
The structures labeled "1" are dendrites. Their membranes contain numerous chemically gated ion channels.

A) The first statement is true but the second statement is false.
B) Both statements are false.
C) Both statements are true.
D) The first statement is false but the second statement is true.
E) Both statements are true and relate to synaptic transmission.

Answer 1

E

Question 2

In the process of continuous action potential propagation,

A) the action potential is triggered by graded depolarization of the initial segment.
B) at threshold, sodium channels begin to open rapidly.
C) local currents depolarize the region just adjacent to the active zone.
D) local currents depolarize a sensitive spot distant from the active zone.
E) A, B, and C

Answer 2

E

Question 3

In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by

A) forming a cellular cord that directs axonal regrowth.
B) producing new axons.
C) clearing away cellular debris.
D) producing more satellite cells that fuse to form new axons.
E) regenerating cell bodies for the neurons.

Answer 3

A

Question 4

Which of the following statements about the action potential is false?

A) The rapid depolarization phase is caused by the entry of potassium ions.
B) During the repolarization phase, sodium channels close and potassium channels open.
C) In the after- hyperpolarization phase, membrane potential approaches the potassium equilibrium potential.
D) During the depolarization phase, membrane potential becomes positive.
E) None of these statements is false-all are true.

Question 5

The most abundant class of neuron in the central nervous system is

A) bipolar.
B) pseudopolar.
C) unipolar.
D) anaxonic.
E) multipolar.

Question 6

neurons are small and have no anatomical features that distinguish dendrites from axons.

A) Multipolar
B) Anaxonic
C) Bipolar
D) Unipolar
E) none of the above

Question 7

Which of the following does not influence the time necessary for a nerve impulse to be transmitted?

A) presence or absence of a myelin sheath
B) length of the axon
C) whether or not the impulse begins in the CNS
D) diameter of the axon
E) presence or absence of nodes

Question 8

At the normal resting potential of a typical neuron, its Na- K ion exchange pump transports

A) 3 intracellular sodium ions for 1 extracellular potassium ion.
B) 3 extracellular sodium ions for 2 intracellular potassium ions.
C) 2 intracellular sodium ions for 1 extracellular potassium ion.
D) 3 intracellular sodium ions for 2 extracellular potassium ions.
E) 1 intracellular sodium ion for 2 extracellular potassium ions.

Question 9

The part of the peripheral nervous system that carries sensory information to the CNS is designated

A) somatic.
B) efferent.
C) motor.
D) autonomic.
E) afferent.

Question 10

Most CNS neurons lack centrioles. This observation explains

A) why CNS neurons grow such long axons.
B) why CNS neurons cannot regenerate.
C) the ability of neurons to communicate with each other.
D) the ability of neurons to produce a resting potential.
E) the ability of neurons to generate an action potential.

Question 11

The axon is connected to the soma at the

A) axon hillock.
B) synapse.
C) synaptic knobs.
D) collaterals.
E) telodendria.

Question 12

Which of the following types of nerve fiber possesses the fastest speed of impulse propagation?

A) type A
B) type B
C) type C
D) type D
E) type E

Question 13

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
When is the neuron in the refractory period?

A) 1
B) 2
C) 3
D) 4

Question 14

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
Neurotransmitter for release is stored in synaptic

A) neurosomes.
B) knobs.
C) telodendria.
D) vesicles.
E) mitochondria.

Question 15

Which of the following is a recognized class of opioid neuromodulators?

A) endorphins
B) enkephalins
C) dynorphins
D) endomorphins
E) all of the above

Question 16

For which of the following functions do active neurons require a supply of ATP?

A) powering the sodium- potassium exchange pump
B) synthesis and reuptake of neurotransmitters
C) axoplasmic transport
D) all of the above
E) A and C only

Question 17

After a stroke, what type of glial cell accumulates within the affected brain region?

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

Question 18

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
Which area of the graph shows when passive depolarization is occurring?

A) 1
B) 2
C) 3
D) 4

Question 19

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
The myelin sheath that covers many CNS axons is formed by

A) satellite cells.
B) astrocytes.
C) oligodendrocytes.
D) microglia.
E) ependymal cells.

Question 20

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
The cytoplasm that surrounds the nucleus of a neuron is called the

A) neuroplasm.
B) nucleoplasm.
C) sarcoplasm.
D) protoplasm.
E) perikaryon.

Question 21

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
The sodium- potassium ion exchange pump

A) transports sodium ions into the cell during depolarization.
B) moves sodium and potassium opposite to the direction of their electrochemical gradients.
C) depends on a hydrogen gradient for energy.
D) transports potassium ions out of the cell during repolarization.
E) must reestablish ion concentrations after each action potential.

Question 22

Branches that may occur along an axon are called

A) synapses.
B) collaterals.
C) hillocks.
D) telodendria.
E) synaptic knobs.

Question 23

How does blocking retrograde axoplasmic transport in an axon affect the activity of a neuron?

A) The neuron becomes unable to produce neurotransmitters.
B) The soma becomes unable to export products to the synaptic knobs.
C) The neuron becomes unable to produce action potentials.
D) The neuron becomes unable to depolarize when stimulated.
E) The soma becomes unable to respond to changes in the distal end of the axon.

Question 24

Which of the following interactions between electrical and chemical gradients does not lead to the establishment of a neuron's resting potential?

A) Potassium ions are repulsed by positive charges outside the cell.
B) Chemical forces tend to drive potassium ions out of the cell.
C) Potassium ions are attracted to the negative charges inside the cell.
D) Chemical and electrical forces both favor sodium ions entering the cell.
E) Electrical forces push sodium ions out of the cell.

Question 25

The largest and most numerous of the glial cells in the central nervous system are the

A) microglia.
B) oligodendrocytes.
C) astrocytes.
D) ependymal cells.
E) satellite cells.

Question 26

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
If the sodium- potassium pumps in the plasma membrane fail to function, all of the following occur, except

A) the membrane will slowly lose its capacity to generate action potentials.
B) the intracellular concentration of sodium ions will increase.
C) the intracellular concentration of potassium ions will increase.
D) the neuron will slowly depolarize.
E) the inside of the membrane will have a resting potential that is more positive than normal.

Question 27

In which of the following would the rate of impulse conduction be the greatest?

A) a nonmyelinated fiber of 10- µm diameter
B) a myelinated fiber of 1- µm diameter
C) a nonmyelinated fiber of 20- µm diameter
D) a myelinated fiber of 10- µm diameter
E) the same in all because of the all- or- none principle

Question 28

The following are the steps involved in transmission at a cholinergic synapse. 1. Chemically gated sodium channels on the postsynaptic membrane are activated.
2) Calcium ions enter the synaptic knob.
3) Acetylcholinesterase hydrolyzes acetylcholine.
4) An action potential depolarizes the synaptic knob at the presynaptic membrane.
5) The synaptic knob reabsorbs choline.
6) Acetylcholine is released from storage vesicles by exocytosis.
7) Acetylcholine binds to receptors on the postsynaptic membrane.
8) Calcium ions are removed from the cytoplasm of the synaptic knob.
The correct sequence for these events is

A) 2, 5, 4, 6, 7, 1, 8, 3.
B) 4, 2, 6, 7, 1, 8, 3, 5.
C) 6, 4, 2, 7, 1, 8, 3, 5.
D) 2, 4, 6, 7, 1, 8, 3, 5.
E) 4, 2, 6, 7, 8, 5, 3, 1.

Question 29

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
The structure labeled "2" is a

A) Nissl body.
B) soma.
C) perikaryon.
D) dendrite.
E) initial segment.

Question 30

Puffer fish poison blocks voltage- gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?

A) Action potentials would lack a repolarization phase.
B) Neurons would depolarize more rapidly.
C) The axon would be unable to generate action potentials.
D) The absolute refractory period would be shorter than normal.
E) None, because the chemically gated sodium channels would still function.

Question 31

Raising the potassium ion concentration in the extracellular fluid surrounding a nerve cell will have which effect?

A) depolarize it
B) hyperpolarize it
C) increase the magnitude of the potassium equilibrium potential
D) decrease the magnitude of the potassium equilibrium potential
E) both A and D

Question 32

If the permeability of a resting axon to sodium ion increases,

A) the membrane potential will depolarize.
B) outward movement of sodium ion will decrease.
C) inward movement of sodium ion will increase.
D) the membrane potential will hyperpolarize.
E) both A and C

Question 33

Damage to ependymal cells would most likely affect the

A) repair of axons.
B) transport of neurotransmitters within axons.
C) formation of myelin sheaths.
D) formation of ganglia.
E) formation of cerebrospinal fluid.

Question 34

open or close in response to binding specific molecules.

A) Chemically gated channels
B) Activated channels
C) Leak channels
D) Voltage- gated channels
E) both C and D

Question 35

Which of the following is not a function of the neuroglia?

A) support
B) maintenance of blood- brain barrier
C) memory
D) phagocytosis
E) secretion of cerebrospinal fluid

Question 36

The largest and most numerous neuroglia in the CNS are the

A) oligodendrocytes.
B) astrocytes.
C) ependymal cells.
D) microglia.
E) none of the above

Question 37

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated

A) spatial summation.
B) inhibition of the impulse.
C) temporal summation.
D) hyperpolarization.
E) impulse transmission.

Question 38

Voltage- gated sodium channels have both an activation gate and an) _ gate.

A) swinging
B) ion
C) repolarization
D) inactivation
E) threshold

Question 39

The effect that a neurotransmitter has on the postsynaptic membrane depends on

A) the nature of the neurotransmitter.
B) the frequency of neurotransmitter release.
C) the characteristics of the receptors.
D) the quantity of neurotransmitters released.
E) all of the above

Question 40

Integral membrane proteins that connect electrical synapses are called

A) receptors.
B) connexons.
C) desmosomes.
D) sodium channels.
E) synapsins.

Question 41

The all- or- none principle states that

A) all stimuli great enough to bring the membrane to threshold will produce identical action potentials.
B) all stimuli will produce identical action potentials.
C) the greater the magnitude of the stimuli, the greater the magnitude of the action potential.
D) only motor stimuli can activate action potentials.
E) only sensory stimuli can activate action potentials.

Question 42

Small, wandering cells that engulf cell debris and pathogens in the CNS are called

A) ependymal cells.
B) microglia.
C) satellite cells.
D) astrocytes.
E) oligodendrocytes.

Question 43

Sensory information from skeletal muscles travels over fibers.

A) type A
B) type B
C) type C
D) type D
E) type E

Question 44

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
neurons are the most common class in the CNS.

A) Multipolar
B) Unipolar
C) Anaxonic
D) Bipolar
E) none of the above

Question 45

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
Which of the following is not a function of the nervous system?

A) integrate sensory information
B) control peripheral effectors
C) coordinate voluntary and involuntary activities
D) sense the internal and external environments
E) direct long- term functions, such as growth

Question 46

Graded potentials

A) are often all- or- none.
B) cause repolarization.
C) produce an effect that increases with distance from the point of stimulation.
D) may be either a depolarization or a hyperpolarization.
E) produce an effect that spreads actively across the membrane surface.

Question 47

Ion channels that are always open are called channels.

A) active
B) regulated
C) gated
D) local
E) leak

Question 48

The equilibrium potential for potassium ion occurs at approximately

A) 0 mV.
B) -90 mV.
C) -70 mV.
D) +66 mV.
E) C or D

Question 49

Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because

A) the endothelium of CNS capillaries forms a blood- brain barrier.
B) the neurolemma is impermeable to most molecules.
C) ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons.
D) astrocytes form a capsule around neurons.
E) oligodendrocytes form a continuous myelin sheath around the axons.

Question 50

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
Which area of the graph shows when membrane potential approaches the potassium equilibrium potential?

A) 1
B) 2
C) 3
D) 4

Question 51

If the chemically gated sodium channels in the postsynaptic membrane were completely blocked,

A) synaptic transmission would fail.
B) smaller action potentials would result.
C) release of neurotransmitter would stop.
D) both A and B
E) A, B, and C

Question 52

Opening of sodium channels in the axon membrane causes

A) depolarization.
B) hyperpolarization.
C) repolarization.
D) increased positive charge inside the membrane.
E) both A and D

Question 53

Which of the following comparisons between neurons and muscle tissue is false?

A) Muscle fibers conduct action potentials at slow speeds.
B) Action potentials last longer in muscle fibers.
C) Resting potentials are greater in muscle fibers.
D) Muscle fibers conduct action potentials only by continuous propagation.
E) Action potentials are briefer in muscle fibers.

Question 54

The axoplasm of the axon contains which of the following?

A) vesicles
B) neurotubules
C) mitochondria
D) neurofibrils
E) all of the above

Question 55

When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs?

A) inhibition of the impulse
B) decrease in speed of impulse transmission
C) temporal summation
D) hyperpolarization
E) spatial summation

Question 56

Which of the following is the most important excitatory neurotransmitter in the brain?

A) glutamate
B) glycine
C) serotonin
D) noradrenaline
E) gamma aminobutyric acid

Question 57

EPSPs excitatory postsynaptic potentials) occur when

A) more calcium ions than usual leak out of a cell.
B) chloride ions enter a cell.
C) hyperpolarizations occur.
D) more potassium ions than usual leak out of a cell.
E) extra sodium ions enter a cell.

Question 58

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
Identify the structure labeled "5."

A) telodendria
B) synaptic terminals
C) axons
D) axosomata
E) dendritic spines

Question 59

If the axon terminal of a motor neuron suddenly became permeable to calcium ion,

A) the motor end plate will be hyperpolarized.
B) the neuron will fire an action potential.
C) the neuron will become unable to stimulate the muscle cell.
D) the motor end plate will be depolarized.
E) neurotransmitter release will be blocked.

Question 60

Functions of astrocytes include all of the following, except

A) responding to neural tissue damage.
B) guiding neuron development.
C) maintaining the blood- brain barrier.
D) forming a three- dimensional framework for the CNS.
E) conducting action potentials.

Question 61

are the most numerous type of neuron in the CNS.

A) Motor neurons
B) Interneurons
C) Sensory neurons
D) Unipolar neurons
E) Bipolar neurons

Question 62

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
Which type of synapse is most common in the nervous system?

A) electrical
B) mechanical
C) chemical
D) processing
E) radiative

Question 63

Neurons that have several dendrites and a single axon are called

A) multipolar.
B) anaxonic.
C) bipolar.
D) tripolar.
E) unipolar.

Question 64

Which of the following is not involved in creating the resting potential of a neuron?

A) The interior of the plasma membrane has an excess of negative charges.
B) membrane permeability for sodium ions greater than potassium ions
C) diffusion of sodium ions into the cell
D) diffusion of potassium ions out of the cell
E) membrane permeability for potassium ions greater than sodium ions

Question 65

Which of the following are a type of glial cell found in the peripheral nervous system?

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

Question 66

After acetylcholinesterase acts, the synaptic knob

A) reabsorbs the choline.
B) reabsorbs the acetylcholine.
C) reabsorbs the acetate.
D) all of the above
E) both B and C

Question 67

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
Which point of the graph shows when potassium ion outflow exceeds sodium ion inflow?

A) 1
B) 2
C) 3
D) 4

Question 68

account for roughly half of the volume of the nervous system.

A) Neuroglia
B) Efferent fibers
C) Axons
D) Synapses
E) Dendrites

Question 69

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
The ion that triggers the release of acetylcholine into the synaptic cleft is

A) chloride.
B) potassium.
C) magnesium.
D) calcium.
E) sodium.

Question 70

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
line the brain ventricles and spinal canal.

A) Astrocytes
B) Oligodendrocytes
C) Microglia
D) Satellite cells
E) Ependymal cells

Question 71

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
When pressure is applied to neural tissue, all these effects are possible, except

A) action potentials are generated spontaneously.
B) a decrease in blood flow.
C) neurons are triggered to divide.
D) the axon becomes inexcitable.
E) glial cells degenerate.

Question 72

The efferent division of the peripheral nervous system innervates:

A) glandular cells
B) skeletal muscle cells
C) smooth muscle cells
D) heart muscle cells
E) all of the above

Question 73

Which of the following is a function of neuroglia?

A) regulate the composition of interstitial fluid
B) provide a supportive framework
C) act as phagocytes
D) produce cerebrospinal fluid
E) all of the above

Question 74

The nervous system controls the skeletal muscles.

A) autonomic
B) sympathetic
C) somatic
D) afferent
E) parasympathetic

Question 75

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
Adrenergic synapses release the neurotransmitter

A) norepinephrine.
B) acetylcholine.
C) dopamine.
D) GABA.
E) serotonin.

Question 76

Figure 11- 2 The Nerve Action Potential
Use Figure 11- 2 to answer the following questions:
Which area of the graph occurs when there is a sudden inrush of sodium ions?

A) 1
B) 2
C) 3
D) 4

Question 77

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
The site of intercellular communication between neurons is the

A) synapse.
B) telodendria.
C) hillock.
D) synaptic knob.
E) collateral.

Question 78

The neurilemma of axons in the peripheral nervous system is formed by

A) oligodendrocytes.
B) astrocytes.
C) microglia.
D) Schwann cells.
E) satellite cells.

Question 79

Which of the following are types of neuroglia?

A) microglia
B) ependymal cells
C) oligodendrocytes
D) astrocytes
E) all of the above

Question 80

Figure 11- 1 The Neuron
Use Figure 11- 1 to answer the following questions:
Which part of the neuron can conduct an action potential?

A) 1
B) 1 and 2
C) 2 and 3
D) 3 and 4
E) 3, 4, and 5