Deck 7: The Nervous System

Question 1

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

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

Answer 1

A

Question 2

Ganglia are clusters of nerve cell bodies located in the periphery.

Answer 2

True

Question 3

The myelin sheaths of PNS neurons are produced by

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

Answer 3

A

Question 4

Sensory nerves regulate muscle contraction.

Question 5

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 6

The brain and spinal cord comprise the

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

Question 7

Retrograde transport

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

Question 8

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 9

Which of the following is NOT true of axonal transport?

A)uses molecular motion
B)can transport anteroretrograde
C)can transport retrograde
D)results from rhythmic waves of contraction.

Question 10

Schwann cells and oligodendrocytes have similar functions.

Question 11

Somatic motor neurons innervate involuntary effectors.

Question 12

A nerve is a bundle of axons in the CNS.

Question 13

Glial cells normally lose their mitotic ability prior to birth.

Question 14

Anteroretrograde transport uses dynein molecular motor proteins.

Question 15

The myelin sheaths of CNS neurons are produced by

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

Question 16

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

Question 17

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 18

Most motor neurons are multipolar.

Question 19

Axoplasmic flow

A)requires actin and Ca²⁺.
B)can be retrograde.
C)is relatively fast.
D)results from rhythmic waves of contraction.

Question 20

Cells supporting neuron cell bodies in ganglia are termed

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

Question 21

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

Question 22

Myelinated axons transmit action potentials more rapidly than unmyelinated axons.

Question 23

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

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

Question 24

Which of the following is NOT a function of neurotrophins?

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

Question 25

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 26

All cells have a membrane potential.

Question 27

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

Question 28

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

A)brain-derived neurotrophic
B)neurotrophin-3
C)nerve growth
D)glial-derived neurotrophic

Question 29

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 30

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

Question 31

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

Question 32

Axonal regeneration is inhibited by

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

Question 33

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

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

Question 34

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 35

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 36

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

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

Question 37

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)forms the blood-brain barrier

Question 38

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 39

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

Question 40

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

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

Question 41

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

Question 42

Blocking ____________ channels would prevent neuronal depolarization.

A)K⁺
B)Cl^-
C)Na⁺
D)Mg²⁺

Question 43

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 44

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 45

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 46

Cells become more negative during hyperpolarization.

Question 47

Nerve cells depolarize due to the influx of K⁺.

Question 48

______ synapses occur between axons of postsynaptic cells and axons of presynaptic cells.

A)Axodendritic
B)Axosomatic
C)Myoneural
D)Axoaxonic

Question 49

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 50

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

Question 51

Conduction of an action potential in a myelinated axon is called

A)point to point conduction.
B)saltatory conduction.
C)refractory conduction.
D)cable conduction.

Question 52

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 53

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 54

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)Both repolarization and relative refractory period are correct.

Question 55

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

Question 56

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 57

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 58

Action potentials frequency encodes stimulus intensity.

Question 59

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

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

Question 60

Sensory neurons for muscle position are the fastest conducting neurons.

Question 61

Neurotransmitter release would be inhibited by

A)stimulating repolarization of the axon terminal.
B)blocking Ca²⁺ influx in the axon terminal.
C)blocking repolarization of the axon terminal.
D)stimulating protein kinase activity.

Question 62

What type of proteins are present at chemical synapses to ensure the close proximity of the presynaptic and postsynaptic membranes?

A)connexins
B)myelin
C)terminal boutons
D)cell adhesion molecules (CAMs)

Question 63

Botulism toxin prevents release of Ach, causing

A)flaccid paralysis.
B)hemiplegia.
C)spastic paralysis.
D)None of the choices are correct.

Question 64

The binding of a NT to its receptor protein causes ion channels to open in the post-synaptic membrane.What type of gates are these?

A)chemically-regulated gates
B)voltage-regulated gates
C)ligand-regulated gates
D)Both chemically-regulated gates and ligand-regulated gates are correct.

Question 65

Most synapses in the body are electrical.

Question 66

Synaptic vesicles are docked to the plasma membrane of the axon terminal by a protein complex called

A)boutons.
B)connexons.
C)synaptotagmins.
D)SNARE.

Question 67

Ligand-gated channels, when activated, allow only Na⁺ to move into the neuron.

Question 68

In a myelinated axon, Na⁺ channels are

A)along the whole length of the axon.
B)every 5 mm.
C)concentrated at the nodes of Ranvier.
D)less numerous at the nodes of Ranvier.

Question 69

Neurotransmitter release from synaptic vesicles is caused by Ca²⁺-synaptotagmin complex interruption of the SNARE complex.

Question 70

A lack of extracellular Ca²⁺ would cause increased release of neurotransmitters.

Question 71

Hyperpolarization in the postsynaptic cell is caused by

A)excitatory postsynaptic potentials.
B)inhibitory postsynaptic potentials.
C)movement of K⁺ out of the cell.
D)Both inhibitory postsynaptic potentials and movement of K⁺ out of the cell are correct.

Question 72

Muscarinic Ach receptors are found in all of the following locations EXCEPT

A)skeletal muscle
B)smooth muscle
C)cardiac muscle
D)glands

Question 73

Chemicals that stimulate action potentials in postsynaptic cells are called

A)hormones.
B)enzymes.
C)neurotransmitters.
D)neurotrophins

Question 74

Chemical synapses

A)have a delayed impulse transmission.
B)utilize gap junctions.
C)occur when two nerve cells are in direct contact with each other.
D)do not require the release of neurotransmitters.

Question 75

Electrical synapses are functionally linked by tight junctions.

Question 76

Which of the following is NOT true of EPSPs?

A)they are graded responses
B)they are capable of summation
C)they have a refractory period
D)they are initiated by neurotransmitters

Question 77

What type of proteins are present in gap junctions that form water-filled channels between neurons?

A)connexons
B)myelin
C)terminal boutons
D)cell adhesion molecules (CAMs)

Question 78

Acetylcholine

A)is always an excitatory neurotransmitter.
B)can bind to adrenergic receptors.
C)is an inhibitory neurotransmitter released by motor neurons.
D)can bind to nicotinic receptors.

Question 79

Which of the following effect(s) Ach synaptic transmission?

A)curare
B)botulinum toxin
C)strychnine
D)both curare and botulinum toxin.

Question 80

Neurotransmitters

A)are released by endocytosis.
B)all bind to the same receptor.
C)usually regulate ion channels.
D)are actively transported across the synaptic cleft.