Deck 7: The Nervous System: Neurons and Synapses

Question 1

A nerve is a bundle of axons in the CNS.

Answer 1

False

Question 2

Which of the following is NOT true of axonal transport?

A)uses molecular motors
B)can transport anterograde or retrograde
C)has one fast and two slow components
D)is a passive process

Answer 2

D

Question 3

Axonal transport from the cell body to the dendrites and axon is retrograde transport.

Answer 3

False

Question 4

The nerve is the basic structural and functional unit of the nervous system.

Question 5

Retrograde transport

A)moves toward the cell body.
B)moves membranes,vesicles,and viruses.
C)uses molecular motor proteins of dynein.
D)All apply.

Question 6

Sensory nerves cause muscle contraction.

Question 7

Ganglia are clusters of nerve cell bodies located in the peripheral nervous system.

Question 8

Which of the following is NOT true of dendrites?

A)transmits action potentials toward the cell body
B)are thin extensions of the cell body
C)transmit graded electrochemical impulses toward the cell body
D)contain receptive areas

Question 9

Which of the following is true of axons?

A)contain receptive areas
B)very thin and short
C)originates at the axon hillock on the cell body
D)transmits graded electrochemical impulses

Question 10

Anterograde transport uses dynein molecular motor proteins.

Question 11

Most brain tumors in adults are found within neurons.

Question 12

The brain and spinal cord comprise the

A)central nervous system.
B)peripheral nervous system.
C)peripheral ganglia.
D)spinal nerves.

Question 13

Somatic motor neurons innervate involuntary effectors.

Question 14

Retrograde axonal transport may be responsible for movement of herpes virus,rabies virus,and tetanus toxin from nerve terminals to the cell body.

Question 15

Glial cells normally lose their mitotic ability prior to birth.

Question 16

Most motor neurons are multipolar.

Question 17

Both neurons and neuroglia will easily divide by mitosis.

Question 18

Sensory neurons

A)are multipolar and carry impulses toward the CNS.
B)are pseudounipolar and carry impulses toward the CNS.
C)are bipolar and carry impulses away from the CNS.
D)are multipolar and carry impulses away from the CNS.

Question 19

Which of the following is NOT a structural classification of neurons?

A)motor neuron
B)bipolar neuron
C)multipolar neuron
D)pseudounipolar neuron

Question 20

Which of the following is NOT a functional classification of neurons?

A)motor or efferent
B)interneuron or association
C)multipolar
D)sensory or afferent

Question 21

Action potential transmission in the PNS is decreased if which cells are damaged?

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

Question 22

All axons in the PNS have a myelin sheath.

Question 23

Destruction of astrocytes would decrease the rate at which action potentials are transmitted.

Question 24

Which type of cell of the CNS is phagocytotic?

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

Question 25

What structure is found around PNS axons that is NOT found around CNS axons?

A)nodes of Ranvier
B)myelin sheath
C)neurilemma
D)plasma membrane

Question 26

All axons in the PNS are surrounded by Schwann cells.

Question 27

The disease ______________ is characterized by destruction of CNS myelin sheaths and the formation of hardened scars.

A)Parkinson's
B)Alzheimer's
C)multiple sclerosis.
D)myasthenia gravis

Question 28

Which type of cell lines the ventricles of the brain and help produce cerebrospinal fluid?

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

Question 29

The gap of exposed axon in the myelin sheath is the

A)neurilemmA.
B)node of Ranvier.
C)sheath of Schwann.
D)white matter.

Question 30

Regeneration of CNS axons may be prevented in part by inhibitory proteins in the membranes of the

A)myelin sheath.
B)neurons.
C)astrocytes.
D)satellite cells.

Question 31

A bundle of axons in the CNS is called a/an

A)nerve.
B)bundle.
C)tract.
D)neuron.

Question 32

White matter is

A)myelinated axons in the CNS.
B)myelinated axons in the PNS.
C)nonmyelinated cell bodies and dendrites in the CNS.
D)nonmyelinated axons in the CNS.

Question 33

Schwann cells and oligodendrocytes have similar functions.

Question 34

Myelinated axons transmit action potentials more rapidly than unmyelinated axons.

Question 35

Axonal regeneration is inhibited by

A)brain-derived neurotrophic factor.
B)nerve growth factor.
C)neurotrophin-3.
D)myelin-associated inhibitory protein.

Question 36

The myelin sheaths of PNS neurons are produced by

A)Schwann cells.
B)oligodendrocytes.
C)ependymal cells.
D)leukocytes.

Question 37

Which division of the nervous system innervates involuntary effectors?

A)central nervous system
B)somatic nervous system
C)autonomic nervous system
D)associative nervous system

Question 38

Cells supporting neuron cell bodies in ganglia are termed

A)astrocytes.
B)ependymal cells.
C)satellite cells.
D)Schwann cells.

Question 39

The myelin sheaths of CNS neurons are produced by

A)Schwann cells.
B)oligodendrocytes.
C)ependymal cells.
D)leukocytes.

Question 40

What type of neuron is found entirely in the CNS?

A)sensory neuron
B)interneuron
C)association neuron
D)Interneuron and association neuron are correct.

Question 41

The most numerous of all cells of CNS nervous tissue are the

A)astrocytes.
B)neurons.
C)Schwann cells.
D)microglia

Question 42

Cells become more negative during hyperpolarization.

Question 43

Degeneration of spinal motor neurons in adults may be due to a lack of ____________ factor.

A)brain-derived neurotrophic (BDNF)
B)neurotrophin-3
C)nerve growth (NGF)
D)glial-derived neurotrophic (GDNF)

Question 44

Which of the following is NOT a function of astrocytes?

A)can take up NT from a synapse
B)can stimulate or inhibit neurons
C)needed to form synapses in the CNS
D)phagocytose foreign material in the CNS
E)form the blood-brain barrier

Question 45

The average resting membrane potential of an axon is

A)-70mV.
B)-85mV.
C)0 mV
D)+30mV.

Question 46

Which cells are needed for the formation of synapses in the CNS?

A)ependymal
B)microglia
C)astrocytes
D)dendrites

Question 47

The blood-brain barrier may prevent medications from reaching brain tissue.

Question 48

Fetal neuron growth requires the actions of a group of chemicals known as

A)endorphins.
B)synapsins.
C)neurotrophins.
D)glutamates.

Question 49

Excitable cells are incapable of maintaining a constant resting membrane potential.

Question 50

Ion channels that open in response to depolarization are called

A)ion-gated channels.
B)voltage-gated channels.
C)stimulation-gated channels.
D)potential-gated channels.

Question 51

The membrane of resting nerve cells is more permeable to ____________ ions than ____________ ions.

A)sodium,potassium
B)calcium,potassium
C)potassium,sodium
D)chloride,potassium

Question 52

Gliotransmitters

A)include calcium ions.
B)can stimulate neurons.
C)form the blood-brain barrier.
D)break down ATP.

Question 53

Blocking ____________ channels would prevent neuron depolarization.

A)K⁺
B)Cl^-
C)Na⁺
D)Mg²⁺

Question 54

The blood-brain barrier prevents hydrophobic molecules from diffusing into the brain.

Question 55

The average resting membrane potential of a neuron is -85mV.

Question 56

Astrocytes can be excited by changes in intracellular Ca²⁺ concentration.

Question 57

Nerve cells depolarize due to the influx of K⁺.

Question 58

Which of the following is NOT a function of neurotrophins?

A)maintaining sympathetic ganglion
B)sustaining neurons that use the NT dopamine
C)embryonic development of neurons
D)regeneration of injured motor neurons

Question 59

The blood-brain barrier results mostly from the action of __________,a type of glial cell.

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

Question 60

All cells have a membrane potential.

Question 61

As the intensity of a stimulus increases,more axons will become activated.This process is called

A)threshold.
B)refraction.
C)recruitment.
D)None apply.

Question 62

During the absolute refractory period,a supramaximal stimulus can bring the cell to threshold.

Question 63

The mechanism that allows many Na⁺ ions to move into the axon is

A)negative feedback.
B)positive feedback.
C)equilibrium feedback.
D)None of the choices are correct.

Question 64

An axon will depolarize only if the membrane potential reaches between -70mV and -55mV.This follows the

A)All-or-none law.
B)recruitment law.
C)graduated law.
D)threshold law.

Question 65

Which ion's movements is responsible for repolarization?

A)influx of K+
B)influx of Na+
C)outward diffusion of K+
D)outward diffusion of Na+

Question 66

Action potentials would be conducted most rapidly by

A)a 10 mm diameter myelinated axon.
B)a 10 mm diameter unmyelinated axon.
C)a 40 mm diameter myelinated axon.
D)a 40 mm diameter unmyelinated axon.

Question 67

Axons require ATP to produce an action potential.

Question 68

During an action potential

A)Na⁺ efflux causes depolarization.
B)K⁺ influx causes repolarization.
C)Na⁺ influx causes depolarization.
D)K⁺ influx causes after-hyperpolarization.

Question 69

What coding system do neurons use to get a greater response?

A)greater amplitude of stimuli
B)greater Na+ concentration gradient
C)increased frequency of stimuli
D)more active Na+/K+ pump

Question 70

The minimum depolarization needed to open Na⁺ gates is called the

A)repolarization.
B)threshold.
C)refractory period.
D)All-or-none law.

Question 71

The period of time when Na⁺ channels are recovering from their inactive state and K⁺ channels are still open is the

A)repolarization.
B)absolute refractory period.
C)relative refractory period.
D)Repolarization and relative refractory period are correct.

Question 72

Conduction without decrement means that action potentials transmitted down an axon will not decrease in amplitude.

Question 73

Local anesthetics block conduction of action potentials in sensory neurons by

A)inhibiting the release of acetylcholine.
B)binding to potassium channels.
C)binding to sodium channels.
D)binding to calcium channels.

Question 74

Repolarization is accomplished through a

A)positive feedback loop.
B)negative feedback loop.
C)relative refractory loop.
D)sodium equilibrium potential.

Question 75

The ability of a neuron to transmit charge through its cytoplasm is called cable properties and is very

A)good.
B)strong.
C)poor.
D)easy.

Question 76

What is NOT true of the relative refractory period?

A)Na+ channels are inactivated
B)many Na+ channels are returning to a closed state
C)K+ is moving out of the axon through its open channels
D)a strong stimulus could cause a depolarization

Question 77

What process is needed to return a membrane to its resting membrane potential with all ions in the correct locations?

A)after-hyperpolarization
B)all-or-none-law
C)Na+/K+ pump
D)refractory period

Question 78

Action potentials frequency encodes stimulus intensity.

Question 79

Both depolarization and repolarization are produced by the diffusion of ions down their concentation gradient.

Question 80

An inactivated ion channel will respond to a strong stimulus.