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Flashcards in Chapter 7 Deck (137):
1

The nervous system is divided into the what two parts?

Central Nervous System and Peripheral Nervous System

2

The central nervous system includes the ____ and _____.

Brain and spinal cord

3

The peripheral nervous system includes the _____ and ______.

Cranial and spinal nerves

4

The nervous system consists of what two kinds of cells?

Neurons and Supporting cells (glial cells)

5

Of the two cells in the nervous system, which one is a functional unit of the nervous system.

Neurons

6

Of the two cells in the nervous system, which one maintains homeostasis?

Glial cells

7

Of the two cells in the nervous system, which is 5 times more common than the other?

Glial cells

8

What gathers and transmits information by responding to stimuli, producing and sending electrochemical impulses, and releasing chemical messages?

Neurons

9

What contains a cell body, dendrites, and axons?

Neurons

10

In the neuron, what contains the nucleus?

Cell body

11

The ______ is the nutritional center and makes macromolecules.

Cell Body

12

Groups of cell bodies in the central nervous system are called what?

Nuclei

13

Groups of cell bodies in the peripheral nervous system are called what?

Ganglia

14

The _____ are what receive the information and convey it to the cell body.

Dendrites

15

The _____ are what conduct impulses away from the cell body.

Axons

16

The _____ is what moves soluble compounds toward the nerve endings via the rhythmic contraction of axon.

Axoplasmic flow

17

The _____ moves large and insoluble compounds bidirectionally along microtubules very fast.

Axonal transport

18

The _______ moves materials away from the cell body.

Anterograde transport

19

The anterograde transport moves materials away from the cell body using the molecular motor _____.

Kinesin

20

The _______ moves materials towards the cell body.

Retrograde transport

21

The retrograde transport moves materials toward the cell body using the molecular motor _____.

Dynein

22

Which transport can viruses and toxins enter the CNS?

Retrograde transport

23

The _______ neurons conduct impulses into the CNS.

Sensory/ Afferent

24

The _______ neurons carry impulses out of the CNS.

Motor/ Efferent

25

The _______ neurons integrate the nervous system activity, and is located entirely inside the CNS.

Association/ Interneurons

26

In the structural classification neuron ________, the cell body site along side of the single process. Example is a sensory neuron.

Pseudounipolar

27

In the structural classification neuron ______, there is one dendrite and one axon that arises from opposite ends of the cell body. Example is a retinal neuron.

Bipolar

28

In the structural classification neuron _____, there are many dendrites and one axon. Example is motor neurons.

Multipolar

29

What are the two supporting cells in the PNS?

Schwann and satellite cells

30

Of the two supporting cells in the PNS, which one myelinates the PNS axons?

Schwann cells

31

What are the four supporting cells in the CNS?

Oligodendrocytes, microglia, astrocytes, and ependymal cells

32

Of the supporting cells in the CNS, which one myelinates several CNS axons?

Oligodendrocytes

33

Of the supporting cells in the CNS, which one appears to be neural stem cells?

Ependymal cells

34

In the PNS, each Schwann cell myelinates _____ of 1 axon by wrapping round and round the axon.

1 mm

35

What is the purpose of the Schwann cells myelinating the axon?

Electrically insulates the axon

36

The uninsulated gap between adjacent Schwann cells are called the _______.

Node of Ranvier

37

Axon regeneration occurs much more readily in which of the two nervous systems?

PNS

38

Oligodendrocytes produce ____ that inhibit regrowth.

Proteins

39

Oligodendrocytes form glial scar tissue that blocks _______.

Regrowth

40

When an axon in the PNS is severed, the distal part of the axon _______.

Degenerates

41

When an axon in the PNS is severed, the Schwann cells survive and form _______.

Regeneration Tubes

42

When the Schwann cells survive the axon being severed, the regeneration tubs releases chemicals that ________.

Attract growing axon

43

Where does the regeneration tube of the Schwann cells guide regrowing axons?

To the synaptic site

44

What promotes fetal nerve growth, is required for survival of many adult neurons, and is important in regeneration?

Neurotrophins

45

What is the most common glial cell?

Astrocytes

46

Which supporting cell is involved in buffering K+ levels, recycling neurotransmitters, regulating adult neurogenesis, and releasing transmitters that regulate neuronal activity?

Astrocytes

47

The ______ allows only certain compounds to enter the brain.

Blood Brain Barrier

48

The blood brain barrier appears to be induced by _____.

Astrocytes

49

In the Resting Membrane Potential, at rest Na+/K+ pump and limited permeability keep _____ high outside the cell.

K+

50

In the Resting Membrane Potential, at rest ____ is very permeable and is high inside the cell. This is attracted by negative charges inside the cell.

K+

51

_______ can discharge their RMP quickly by rapid changes in permeability to ions, and neurons and muscles do this to generate and conduct impulses, therefore muscles and nerve cells are considered excitable.

Excitable Cells

52

Membrane potential is measured by placing 1 electrode _______ and 1 ______.

Inside the cell and outside the cell

53

______ occurs when membrane potential becomes more positive.

Depolarization

54

________ in the membrane potential becomes more negative than resting membrane potential.

Hyperpolarization

55

______ is when the membrane potential returns to resting membrane potential.

Repolarization

56

Membrane potential occurs by ion flow through ______. Some are normally opened and some closed.

Membrane channels

57

_____ leakage channels are always open in the membrane ion channels.

K+

58

Closed channels have ______ that can be opened.

Molecular gates

59

Voltage gated channels are opened by _______.

Depolarization.

60

Voltage gated _____ and ____channels are closed in resting cells.

K+ and Na+

61

The RMP is determined to be ____ in most neurons.

-70mV

62

A nucleus is a group of _____ in the CNS.

Somas

63

A _____ neuron has two processes, one at either end of the soma.

Bipolar

64

Each Schwann cell wraps only about ____ of axon, leaving gaps of exposed axon between the adjacent Schwann cells.

A millimeter

65

Another name for an association neuron is an ______.

Interneuron

66

An ______ is a wave of membrane potential change that sweeps along the axon from some to synapse.

Action Potential

67

The wave in an action potential is formed by rapid depolarization of the membrane by Na+ ____ and followed by rapid repolarization by K+ _____.

Influx; Efflux

68

The wave in an action potential is formed by rapid depolarization of the membrane by Na+ ____ and followed by rapid repolarization by K+ _____.

Influx; Efflux

69

In the mechanism of action potential, in _________ at threshold VG Na+ channels open, Na+ is driven inward by its electrochemical gradient, and causes rapid change in MP from -70 to +30 mV.

Depolarization

70

In the mechanism of action potential, in _____ VG Na+ channels close while VG K+ channels open, electrochemical gradient drives K+ outward, and repolarizes axon back to RMP.

Repolarization

71

Depolarization and repolarization occur via ______.

Diffusion

72

_______ and ______ do not require active transport, and after an action potential Na+/K+ pump extrudes Na+, recovers K+.

Depolarization and repolarization

73

When a membrane potential reaches threshold, an ______ is irreversibly fired.

Action potential

74

The reason there is an irreversibly fire back in the action potential is because positive feedback opens more and more _______ channels.

Na+

75

Shortly after the Na+ channels open, the Na+ channels close and become inactivated until _______.

Repolarization

76

The increased stimulus intensity causes more _______ to be fired. The size remains constant.

Action Potentials

77

______ refractory period is when the membrane cannot produce another action potential because Na+ channels are inactivated.

Absolute

78

_____ refractory period occurs when VG K+ channels are open, making it harder to depolarize to threshold.

Relative

79

______ refer to how axons properties affect its ability to conduct currents.

Cable Properties

80

Cable properties includes high resistance of ______. The resistance decreases as axons diameter increases.

Cytoplasm

81

In cable properties, the current leaks out through _____.

Ion channels

82

When conduction is an unmyelinated axon, an ______ reaches threshold and fires AP, its Na+ influx depolarizes adjacent regions to threshold.

Axon Hillock

83

When the conduction is a myelinated axon, ____ cant flow across the myelinated membrane, thus no AP's occur under myelin and no current leaks which increases the current speed.

Ions

84

A _____ is a functional connection between a neuron (presynaptic) and another cell (postsynaptic).

Synapse

85

What are the two different kinds of synapses?

Chemical and electrical

86

Synaptic transmission at chemical synapses is vis ______.

Neurotransmitters

87

Which synapse is rare in the nervous system?

Electrical synapses

88

In an electrical synapse, depolarization flows from presynaptic into postsynaptic cell through channels called _______.

Gap junctions

89

The gap junctions in an electrical synapse are formed by ______ proteins that are found in smooth and cardiac muscles, brain, and glial cells.

Connexin

90

The synaptic cleft separates the ______ of the presynaptic from the postsynaptic cell.

Terminal Bouton

91

Neurotransmitters in the chemical synapse are located in the _______.

Synaptic Vesicles

92

The vesicles fuse with the terminal bouton membrane that release neurotransmitters by ____.

Exocytosis

93

The amount of neurotransmitters released in a chemical synapse depends upon the frequency of ________.

Action Potentials

94

The AP gets smaller as it travels down the membrane. T/F

False

95

All parts of the neuron membrane are capable of carrying action potentials.

False

96

The word "saltatory" comes from the Latin word "to climb" and refers to the depolarization phase of the action potential.

False

97

In a synaptic transmission, the AP's travel down the axon to depolarize the ______.

Terminal Bouton

98

In a neurotransmitter release, action potentials reach the axon terminal and Ca2+ enters the axon terminal via ________.

Voltage Gated Channels

99

When neurotransmitters are release, the Ca2+ binds to sensor proteins in the ______.

Cytoplasm

100

Neurotransmitters are released from the vesicles into the ______.

Synapse

101

In the synaptic transmission, the neurotransmitter diffuses across the cleft and binds to receptor proteins on the _______ membrane, opening ligand or chemically regulated ion channels.

Postsynaptic

102

In the synaptic transmission, ______ channels cause EPSP's.

Depolarizing

103

In the synaptic transmission, _____ channels cause IPSP's.

Hyperpolarizing

104

If a membrane potential in the postsynaptic cell reaches threshold at the ______, a new action potential is generated.

Axon Hillock

105

What is the most widely occurring neurotransmitter?

Acetylcholine

106

Acetylcholine is found in the ____ and ____, and also occurs at all neuromuscular junctions.

Brain and ANS

107

Acetylcholine has ____ and ______ receptor subtypes that can be excitatory or inhibitory.

Nicotinic and Muscarinic

108

________ channels contain both a NT receptor site and an ion channel, and opens when ligand (NT) binds.

Ligand Gated

109

A nicotinic ACh Channel is formed by 5 ______ subunits.

Polypeptide

110

In a G-protein coupled channel, _____ receptors are not part of the ion channel.

NT

111

______ ACh channels are the binding of 1 ACh activates G-protein cascade which affects gated K+ channels.

Muscarinic

112

In the muscarinic ACh channel, the opening of channels causes ______.

Hyperpolarization

113

In the muscarinic ACh channel, the closing of channels causes ______.

Depolarization

114

______ inactivates ACh, by terminating its actions and is located in the cleft.

Acetylcholinesterase

115

_____ neurons use acetylcholine as NT.

Cholinergic

116

The large synapses on skeletal muscles are called _____.

Neuromuscular junctions

117

What blocks the ACh action at neuromuscular junctions?

Curare

118

Monoamine NT's include serotonin, norepinephrine, epinephrine, and _____.

Dopamine

119

Serotonin is derived from _________.

Trytophan

120

Norepinephrine and epinephrine are derived from ______.

Tyrosine

121

Histamine is derived from an _______.

Amino acid

122

_______ is involved in regulation of mood, behavior, appetite, and cerebral circulation.

Serotonin

123

What are the two major dopamine systems in the brain?

Nigrostriatal and Mesolimbic

124

Nigrostriatal dopamine system originates in the __________ and is involved in motor control.

Substantia nigra

125

The mesolimbic dopamine system is involved in ____ and emotional reward.

Behavior

126

Of the two dopamine systems in the brain, which one is activated do to addictions?

Mesolimbic

127

Glutamic acid and aspartic acid are major _____ excitatory NT's.

CNS

128

Glycine is an ______ NT.

Inhibitory

129

_______ is the most common NT in the brain.

GABA

130

Endorphins, enkephalins, and dynorphins are endogenous ____ NT's.

Opioid

131

Neuropeptide ____ is the most common neuropeptide. It inhibits glutamate in the hippocampus, and has a powerful stimulator of appetite.

Y

132

______ are the only lipid NT's.

Endocannabinoids

133

NO and CO are _____ NT's.

Gaseous

134

_______ are graded in magnitude, have no threshold, cause depolarization, summate, and have no refractory period.

EPSP's

135

_________ takes place when EPSP's from different synapses occur in postsynaptic cells at the same time.

Spatial Summation

136

________ occurs because EPSP's that occur closely in time can sum before they fade.

Temporal Summation

137

________ occurs when 1 neuron synapses onto an axon or bouton of another neuron, inhibiting release of it NT.

Presynaptic Inhibition