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Biology 2312 > Chapter 43 > Flashcards

Chapter 43 Flashcards

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1
Q

What do sensory receptors do?

A

detect stimuli

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2
Q

What do motor effectors do?

A

respond to stimuli

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3
Q

What is another name for sensory neurons?

A

afferent neurons

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4
Q

What do sensory neurons do?

A

carry impulses from sensory receptors to the CNS

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5
Q

What is another name for motor neurons?

A

efferent neurons

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6
Q

What do motor neurons do?

A

carry impulses from the CNS to effectors (muscles and glands)

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7
Q

What is another name for interneurons?

A

association neurons

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8
Q

Where are interneurons located?

A

in the brain and spinal cord (of vertebrates)

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9
Q

What do interneurons do?

A

help provide more complex reflexes and higher associative functions, including learning and memory

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10
Q

Sensory and motor neurons constitute

A

the PNS in vertebrates

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11
Q

Motor neurons that stimulate skeletal muscles make up the

A

somatic nervous system

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12
Q

Motor neurons that stimulate smooth/cardiac muscles and glands make up

A

the autonomic nervous system

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13
Q

What are the two further divisions of the autonomic nervous system?

A

sympathetic and parasympathetic divisions

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14
Q

What is the neuron cell body?

A

enlarged region containing the nucleus

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15
Q

What are dendrites?

A

cytoplasmic extensions of a neuron

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16
Q

What are dendritic spines?

A

branches of dendrites that further increase the surface area available to receive stimuli

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17
Q

Each neuron has how many axons?

A

just one

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18
Q

The supporting cells of neurons are collectively called

A

neuroglia

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19
Q

How big are neuroglia compared to neurons?

A

1/10th the size of neurons

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20
Q

How numerous are neuroglia compared to neurons?

A

10 times more numerous than neurons

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21
Q

What are the two most important kinds of neuroglia?

A

Schwann cells and oligodendrocytes

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22
Q

Schwann cells and oligodendrocytes both produce

A

myelin sheaths

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23
Q

Which neuroglium produces myelin sheaths in the PNS?

A

Schwann cells

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24
Q

Which neuroglium produces myelin sheaths in the CNS?

A

oligodendrocytes

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25
Q

What is white matter?

A

In the CNS, myelinated axons form white matter

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26
Q

What is gray matter?

A

unmyelinated dendrites and cell bodies form gray matter

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27
Q

How are myelinated axons organized in the PNS?

A

arranged in bundles

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28
Q

What are the intervals for nodes of Ranvier?

A

1 to 2 micrometers

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29
Q

The resting membrane potential of many vertebrate neurons ranges from

A

-40 to -90 millivolts, or 0.04 V to 0.09 V

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30
Q

The inside of the cell is (+/-) charged whereas the outside is (+/-) charged.

A

The inside of the cell is negatively charged and the outside is positively charged.

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31
Q

What are the two contributors to the membrane potential?

A

sodium/potassium pump; ion channels

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32
Q

How many of each ion does the sodium/potassium pump exchange?

A

The sodium potassium pump brings in 2 potassium ions for every 3 sodium ions it pumps out

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33
Q

Describe the relative amounts of Na+ and K+ inside and outside the cell in a resting potential.

A

The inside has high K+ and low Na+ concentrations, whereas the outside has high Na+ and low K+ concentrations.

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34
Q

Refer to Figure 43.5 on page 890. Describe how the sodium/potassium pump works. (6)

A

carrier in membrane binds to intracellular sodium; ATP phosphorylates protein with bound sodium; phosphorylation causes conformational change in protein, which reduces affinity for Na+ and releases Na+ out of the cell; this conformation has affinity for K+ so 2 K+ ions bind; binding of K+ causes dephospho rylation of protein; dephosphorylation of protein triggers back to original conformation with low affinity for K+ so K+ diffuses into cell

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35
Q

Are there more K+ or Na+ ion channels in the cell membrane?

A

there are more K+ ion channels in the membrane

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36
Q

What are ion channels?

A

membrane proteins that form pores through the membrane, allowing diffusion of specific ions across the membrane

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37
Q

What is the equilibrium potential?

A

the balance between the diffusional force and the electrical force

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38
Q

Write out the Nernst equation (pg. 890)

A

write out

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39
Q

What are the two types of disruptions to the resting membrane potential?

A

graded potentials and action potentials

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40
Q

What are graded potentials?

A

small continuous changes to membrane potentials

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41
Q

What are action potentials?

A

transient disruptions of the potential triggered by a threshold change in potential

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42
Q

Why does the resting potential arise?

A

because of the permeability of the membrane to K+ through leakage channels

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43
Q

What are the two types of gated channels?

A

ligand-gated (chemically gated) OR voltage-gated channels (respond to changes in membrane potential)

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44
Q

Ligand-gated channels lead to what type of potential?

A

graded potentials that determine whether an axon will fire

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45
Q

Voltage-gated channels lead to what type of potential?

A

action potential

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46
Q

Gated ion channels in dendrites respond to

A

the binding of signaling molecules

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47
Q

Which molecules act as ligands and induce the opening of ligand-gated channels?

A

hormones and neurotransmitters

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48
Q

Permeability changes are measurable as

A

depolarizations or hyperpolarizations of the membrane potential

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49
Q

What do depolarizations do?

A

makes the membrane potential less negative (more positive)

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50
Q

What do hyperpolarizations do?

A

makes the membrane more negative

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51
Q

What are the two classifications of graded potentials?

A

depolarizing or hyperpolarizing

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52
Q

What is summation?

A

the ability of graded potentials to combine

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53
Q

Action potentials result when

A

depolarization reaches a threshold

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54
Q

What is the threshold potential?

A

level of depolarization needed to produce an action potential

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55
Q

The action potential is caused by what class of ion channel?

A

voltage-gated ion channels

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56
Q

Voltage-gated ion channels open and close in response to

A

changes in the membrane potential

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57
Q

Voltage-gated channels are found in what two cell types of the body?

A

neurons and muscle cells

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58
Q

What are the two different channels used to create an action potential in neurons?

A

voltage-gated Na+ channels and voltage-gated K+ channels

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59
Q

Which voltage-gated ion channel (Na+ or K+) has more complex behavior?

A

the voltage-gated Na+ channel

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60
Q

The voltage-gated Na+ channel has what two gates?

A

an activation gate and an inactivation gate

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61
Q

In the resting state of the voltage-gated Na+ channel, which gates are opened and closed?

A

the activation gate is closed and the inactivation gate is open

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62
Q

What happens to the gates of the voltage-gated Na+ channel when the threshold voltage is reached?

A

the activation gate opens rapidly, which leads to an influx of Na+ ions

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63
Q

What happens after the influx of Na+ ions after the threshold voltage is reached?

A

the inactivation gate closes, which stops the influx of Na+ ions and leaves the channel in a temporarily inactivated state

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64
Q

How is the channel returned to its resting state following the influx of Na+ ions?

A

the activation gate closes and the inactivation gate opens, which leads to a transient influx of Na+ that depolarizes the membrane in response to a threshold voltage

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65
Q

How many gates does the voltage-gated K+ channel have? (2)

A

a single activation gate that is closed in the resting state; in response to a threshold voltage, it opens slowly

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66
Q

When the voltage-gated K+ channel activation gate, what happens?

A

an efflux of K+ begins, which contracts the effect of the Na+ channel and repolarizes the membrane

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67
Q

What are the three phases of the action potential?

A

rising phase, falling phase, undershoot phase

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68
Q

What happens in the rising phase?

A

equilibrium between the diffusion of K+ out of the cell and voltage pulling K+ into the cell

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69
Q

What happens in the rising phase? (2)

A

stimulus causes above-threshold voltage; sodium channel activation gate opens

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70
Q

What happens in the top of the curve? (3)

A

maximum voltage reached; sodium channel inactivation gate closes; potassium gate opens

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71
Q

What happens in the falling phase?

A

undershoot occurs as excess potassium diffuses out before potassium channel closes

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72
Q

What happens as equilibrium is restored?

A

potassium channel gate closes; Na+ channel activation gate closes and inactivation gate opens

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73
Q

Why does the membrane potential never quite reach +60 mV?

A

because the inactivation gate of the Na+ channel closes, terminating the rising phase

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74
Q

What is the nature of action potentials?

A

action potentials are separate, all-or-none events

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75
Q

Do action potentials interfere with each other?

A

no, but graded potentials can

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76
Q

Why don’t action potentials interfere with each other?

A

After Na+ channels fire, they remain in an inactivated state until the inactivation gate reopens, preventing any summing of effects

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77
Q

What is the absolute refractory period? (2)

A

when the Na+ channels remain in an inactivated state after they fire but before the inactivation gate reopens; membrane cannot be stimulated

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78
Q

What is the relative refractory period?

A

stimulation produces action potentials of reduced amplitude

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79
Q

The production of an action potential results entirely from

A

the passive diffusion of ions

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80
Q

At the end of an action potential, what is the ion composition like?

A

cytoplasm contains a little more Na+ and a little less K+ than it did at rest, but the Na/K pump compensates for this change

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81
Q

The sodium/potassium pump operates using what kind of transport?

A

active transport

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82
Q

What is the relationship between velocity of conduction and the diameter of the axon?

A

the velocity of conduction is greater if the diameter of the axon is large

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83
Q

What is the relationship between myelination and velocity of conduction?

A

the velocity of conduction is greater if the axon is myelinated

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84
Q

Why does velocity increase as diameter increase?

A

because electrical resistance is inversely proportional to cross-sectional area

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85
Q

Are large diameter axons found in vertebrates or invertebrates?

A

found primarily in invertebrates

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86
Q

What is saltatory conduction?

A

when depolarizations spread quickly beneath insulating myelin to trigger the opening of voltage-gated channels at the next node

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87
Q

Action potentials in myelinated axons are only produced at

A

the nodes of Ranvier

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88
Q

What are synapses?

A

specialized intercellular junctions that are found at the end of an axon

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89
Q

What is the presynaptic cell?

A

the neuron that is sending the action potential

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90
Q

What is the postsynaptic cell?

A

the neuron that is receiving the action potential

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91
Q

What are the two basic types of synapses?

A

electrical and chemical synapses

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92
Q

What are electrical synapses?

A

electrical synapses involve direct cytoplasmic connections formed by gap junctions between the pre and post synaptic neurons

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93
Q

Electrical synapses are common in what types of organisms?

A

common in invertebrate nervous systems, but are rare in vertebrates

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94
Q

The vast majority of vertebrate synapses are what type of synapse?

A

chemical synapses

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95
Q

What is the synaptic cleft?

A

a narrow space that separates these two cells

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96
Q

The end of a presynaptic axon is swollen and contains

A

numerous synaptic vesicles

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97
Q

Each synaptic vesicle is packed with chemicals called

A

neurotransmitters

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98
Q

When action potentials arrive at the end of the axon?

A

they stimulate the opening of voltage-gated calcium channels, causing a rapid inward diffusion of Ca2+

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99
Q

The rapid inward diffusion of Ca2+ triggers

A

a complex series of events that leads to the fusion of synaptic vesicles with the plasma membrane and the release of the neurotransmitter by exocytosis

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100
Q

What is the relationship between the frequency of action potentials and the number of vesicles that release neurotransmitters?

A

The higher the frequency of action potentials, the greater the number of vesicles that release neurotransmittesr

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101
Q

What happens after the neurotransmitters are released?

A

The neurotransmitters are released to the other side of the cleft and bind to the chemical or ligand-gated receptor proteins in the membrane of the post synaptic cell

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102
Q

Why is the presence of neurotransmitters in the synaptic cleft tightly controlled?

A

they must be removed rapidly to allow new signals to be transmitted

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103
Q

What are three ways in which neurotransmitters are removed from the synaptic cleft?

A

enzymatic digestion, reuptake of neurotransmitters by the original neuron, uptake by glial cells

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104
Q

What is acetylcholine?

A

a neurotransmitter that crosses the synapse between a motor neuron and a muscle fiber

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105
Q

The synapse in which acetylcholine is found is called

A

a neuromuscular junction

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106
Q

How does acetylcholine work?

A

binds to its receptor proteins in the post-synaptic membrane and causes ligand-gated ion channels within these proteins to open

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107
Q

What is the result of acetylcholine opening ligand-gated ion channels?

A

that site on the post synaptic membrane produces a depolarization called an excitatory postsynaptic potential (EPSP)

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108
Q

What are the consequences for the production of an EPSP?

A

The EPSP, if strong enough, can open the voltage-gated channels for Na+ and K+ that are responsible for action potentials

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109
Q

How is acetylcholine removed?

A

Acetylcholinase is an enzyme found in the postsynaptic membrane that eliminates acetylcholine by cleaving it into inactive fragments

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110
Q

What are 2 potent inhibitors of acetylcholinase?

A

nerve gas; parathion (an agricultural insecticide)

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111
Q

How can acetylcholinase inhibitors harm humans? (2)

A

can cause severe spastic paralysis; death if paralysis affects respiratory system

112
Q

Is acetylcholine restricted to use for skeletal muscle cells?

A

no

113
Q

What is the function of glutamate as a neurotransmitter?

A

major excitatory neurotransmitter for the vertebrate CNS

114
Q

Excitatory neurotransmitters act to

A

stimulate action potentials by producing EPSPs

115
Q

What is the consequence of hypersensitivity to glutamate?

A

causes someone to suffer from Huntington disease which leads to neurodegeneration

116
Q

Give two examples of inhibitory neurotransmitters.

A

glycine, GABA

117
Q

What do glycine and GABA do?

A

cause the opening of ligand-gated channels for the chloride ion, which has a concentration gradient favoring its diffusion into the neuron

118
Q

What is the effect of glycine and GABA diffusing Cl- into the neuron? (2)

A

the inside of the membrane is even more negative than it usually is at rest; is an example of hyper polarization called inhibitory post synaptic potential (IPSP)

119
Q

What does EPSP stand for?

A

excitatory post synaptic potential

120
Q

What does IPSP stand for?

A

inhibitory post synaptic potential

121
Q

How does the drug diazepam (Valium) work?

A

causes sedation by enhancing the binding of GABA to its receptors, increasing the effectiveness of GABA at the synapse

122
Q

What are the four biogenic amines?

A

epinephrine/adrenaline, dopamine, norepinephrine, serotonin

123
Q

Epinephrine, norepinephrine, and dopamine are derived from

A

tyrosine

124
Q

Epinephrine, norepinephrine, and dopamine are included in the category called

A

catecholamines

125
Q

Serotonin Is derived from

A

tryptophan

126
Q

Epinephrine is released into

A

the blood as a hormonal secretion

127
Q

Norepinephrine is released at

A

the synapses of neurons in the sympathetic nervous system

128
Q

What is dopamine?

A

very important neurotransmitter used in some areas of the brain controlling body movement

129
Q

Degeneration of particular dopamine-releasing neurons results in

A

resting muscle tremors in Parkinson disease

130
Q

How are people with Parkinson disease treated?

A

with L-dopa

131
Q

Schizophrenia is associated with

A

excessive activity of dopamine-releasing neurons

132
Q

How are people with schizophrenia treated?

A

chlorpromazine (Thorazine), which blocks the production of dopamine

133
Q

What is serotonin? (2)

A

neurotransmitter involved in the regulation of sleep; implicated in various emotional states

134
Q

What might be one possible cause of depression?

A

insufficient activity of neurons that release serotonin

135
Q

How are people with clinical depression treated?

A

Fluoxetine (prozac), which blocks the elimination of serotonin in the synaptic cleft

136
Q

Drugs like prozac are termed

A

selective serotonin reuptake inhibitors (SSRIs)

137
Q

What are neuropeptides?

A

a type of polypeptide released at the synapse that may have a typical neurotransmitter function or may have a subtle long-term effect on the postsynaptic neuron

138
Q

Neuropeptides that have a subtle long-term effect on the post synaptic neuron are called

A

neuromodulators

139
Q

How many kinds of neurotransmitters can an axon release?

A

generally only one

140
Q

What is substance P?

A

an important neuropeptide released at synapses in the CNS by sensory neurons activated by painful stimuli

141
Q

The intensity with which pain is perceived partly depends on what two neuropeptides?

A

enkephalins and endorphins

142
Q

What are enkephalins? (2)

A

inhibit the passage of pain information back up to the brain; released by axons descending from the brain into the spinal cord

143
Q

What are endorphins? (2)

A

released by neurons in the brain stem; block the perception of pain

144
Q

What are two derivatives of opium?

A

morphine and heroin

145
Q

Why are opium and its derivatives used as analgesic drugs?

A

they have a similar enough chemical structure to bind to the receptors normally used by enkephalins/endorphins.

146
Q

What is the first gas known to act as a regulatory molecule in the body?

A

nitric oxide

147
Q

How is NO transferred?

A

diffuses through membranes

148
Q

How is NO produced?

A

produced as needed from arginine

149
Q

What does NO do?

A

diffuses out of the presynaptic axon and into the neighboring cells by simply passing through the lipid portions of the plasma membranes

150
Q

What is the role of NO in the PNS? (4)

A

innervates the gastrointestinal tract, penis, respiratory passages, cerebral blood vessels

151
Q

How does sildenafil/Viagra work?

A

increases the release of NO in the penis, enabling and prolonging an erection

152
Q

How does the brain use NO?

A

uses NO as a neurotransmitter, where it appears to participate in the processes of learning and memory

153
Q

What is synaptic integration?

A

when EPSPs and IPSPs add up amongst each other

154
Q

A post synaptic neuron is like a (analogy)

A

switch that is either turned on or remains off

155
Q

What are the two ways that a membrane can reach the threshold voltage?

A

by many different dendrites producing EPSPs that sum to the threshold voltage OR by one dendrite producing repeated EPSPs that sum to the threshold voltage

156
Q

What is spatial summation?

A

when many different dendrites produce EPSPs that sum to the threshold voltage

157
Q

What is temporal summation?

A

when one dendrite produces repeated EPSPs that sum to the threshold voltage

158
Q

What happens in spatial summation?

A

graded potentials due to dendrites from different presynaptic neurons that occur at the same time add together to produce an above-threshold voltage

159
Q

What happens in temporal summation?

A

a single dendrite produces a sufficient depolarization to produce an action potential if it produces EPSPs that are close enough in time to sum to a depolarization greater than the threshold

160
Q

How long does a typical EPSP last for?

A

15 milliseconds

161
Q

What is habituation?

A

when certain cells of the nervous system are exposed to a constant stimulus and cells lose their ability to respond to that stimulus

162
Q

How are synapses affected by habituation?

A

If receptor proteins within synapses are exposed to high levels of neurotransmitter molecules for prolonged periods, the postsynaptic cell responds by decreasing the number of receptor proteins in its membrane

163
Q

What is the only major phylum to lack nerves?

A

sponges

164
Q

The simplest nervous system occurs in

A

cnidarians, in which all the neurons are similar and linked together in a nerve net

165
Q

What are the simplest animals with associative activity?

A

free-living flatworms (phylum Platyhelminthes)

166
Q

How many nerve cords do flatworms have?

A

2

167
Q

What are the three divisions of contemporary vertebrate brains?

A

hindbrain, midbrain, forebrain

168
Q

What is another name for the hindbrain?

A

rhombencephalon

169
Q

What is another name for the midbrain?

A

mesencephalon

170
Q

What is another name for the forebrain?

A

prosencephalon

171
Q

What are the three components of the hindbrain in fishes?

A

cerebellum; pons; medulla oblongata

172
Q

The hindbrain in fishes may be considered

A

an extension of the spinal cord responsible for coordinating motor reflexes

173
Q

The hindbrain in fishes ntegrates

A

sensory signals coming from muscles and coordinates the pattern of motor responses

174
Q

What is the function of the cerebellum? (2)

A

coordination of movements; balance

175
Q

What is the function of the pons? (2)

A

reticular-activating system; autonomic functions

176
Q

What is the function of the medulla oblongata? (3)

A

sensory nuclei; reticular-activating system; autonomic functions

177
Q

The midbrain in fishes is primarily composed of

A

the optic tectum

178
Q

What does the optic tectum do in fishes?

A

receives and processes visual information

179
Q

What does the forebrain in fishes do?

A

processing olfactory information

180
Q

How is brain development different in fishes compared to other vertebrates?

A

brains of fishes continue growing throughout lifetime; in other vertebrates, brain development is usually done in infancy

181
Q

What is neurogenesis?

A

production of new neurons

182
Q

Starting with amphibians and continuing with reptiles, the processing of sensory information is increasing

A

centered in the forebrain

183
Q

The forebrain in reptiles/amphibians/birds/mammals is composed of what two elements?

A

diencephalon; telencephalon

184
Q

What does the diencephalon consist of? (2)

A

thalamus and hypothalamus

185
Q

What is the thalamus?

A

integration and relay center between incoming sensory information and the cerebrum

186
Q

What is the hypothalamus?

A

participates in basic drives and emotions and controls the secretions of the pituitary gland

187
Q

What controls the secretions of the pituitary gland?

A

the hypothalamus

188
Q

Where the telencephalon located?

A

front of the forebrain

189
Q

What does the telencephalon do?

A

devoted to associative activity

190
Q

What is the cerebrum? (2)

A

center for correlation, association, and learning in the mammalian brain; receives sensory data from the thalamus and issues motor commands to the spinal cord via axons

191
Q

In vertebrates, the CNS is composed of

A

the brain and the spinal cord

192
Q

The human cerebrum is split into

A

right and left cerebral hemispheres

193
Q

What connects the right and left cerebral hemispheres?

A

corpus callosum

194
Q

The cerebral hemispheres are further divided into (4)

A

frontal, parietal, temporal, and occipital lobes

195
Q

Each cerebral hemisphere receives sensory input from

A

the opposite (contralateral) side of the body

196
Q

Much of the neural activity of the cerebrum occurs in

A

the cerebral cortex

197
Q

Describe the physical appearance of the cerebral cortex.

A

layer of gray matter only a few millimeters thick

198
Q

How many nerve cells are in the cerebral cortex?

A

over 10 billion

199
Q

Why are convolutions in the cerebral cortex important?

A

increase surface area

200
Q

What are the three activities of the cerebral cortex?

A

motor, sensory, associative

201
Q

Where is the primary motor cortex located?

A

along the gyrus on the posterior border of the front lobe, just in front of the central sulcus

202
Q

A gyrus is a

A

convolution

203
Q

A sulcus is a

A

crease

204
Q

Where is the primary somatosensory complex located?

A

just behind the central sulcus, on the anterior edge of the parietal lobe

205
Q

Each point in the area of the primary somatosensory complex receives input from

A

sensory neurons serving skin and muscle senses

206
Q

Large areas of the primary motor/primary somatosensory cortexes are devoted to

A

fingers/lips/tongue because of the need for manual dexterity and speech

207
Q

Where is the auditory cortex located?

A

within the temporal lobe

208
Q

Where is the visual cortex located?

A

on the occipital lobe

209
Q

What is the association cortex? (2)

A

the portion of the cerebral cortex that is not occupied by these motor and sensory cortices; location of higher mental activities

210
Q

The association cortex makes up what percent of the surface of the cerebral cortex in humans?

A

95%

211
Q

What are basal ganglia?

A

aggregates of neuron cell bodies located deep within white matter of cerebrum that produce islands of gray matter

212
Q

Damage to specific regions of the basal ganglia can result in what?

A

can result in resting tremor of muscles that is characteristic of Parkinson’s disease

213
Q

Somatosensory information is handled by which lobe?

A

the parietal lobe

214
Q

What brain structure is responsible for body temperature/hunger/thirst/various emotional states?

A

hypothalamus

215
Q

What is the brainstem?

A

term that collectively refers to midbrain/pons/medulla oblongata

216
Q

What are the three major components of the limbic system?

A

hippocampus, amygdala, hypothalamus

217
Q

The limbic system is responsible for

A

emotional responses

218
Q

The hippocampus is believed to be important in

A

the formation and recall of memories

219
Q

What is the reticular formation?

A

diffuse collection of neurons in the brainstem

220
Q

What does the reticular activating system do?

A

controls consciousness and alertness

221
Q

All sensory pathways feed into what system?

A

the reticular activating system

222
Q

Drugs like anesthetics and barbiturates can depress

A

neural pathways from the reticular formation to the cortex

223
Q

What controls both sleep and the waking state?

A

reticular-activating system

224
Q

What does EEG stand for?

A

electroencephalogram

225
Q

What is an EEG?

A

a recording of electrical activity that is used to monitor brain state

226
Q

What are alpha waves?

A

large, slow waves found in awake, relaxed individuals with closed eyes

227
Q

What are beta waves?

A

rapid waves found in alert individuals with opened eyes

228
Q

What kind of brain waves are observed in sleep?

A

theta and delta waves, which are very slow waves

229
Q

When an individual is in REM sleep, what are the brain waves like?

A

alpha waves

230
Q

Which hemisphere is the dominant hemisphere for language in most right-handed people?

A

left hemisphere

231
Q

Where is Wernicke’s area located?

A

in the parietal lobe between the primary auditory and visual areas

232
Q

What is the function of Wernicke’s area? (2)

A

important for language comprehension and the formulation of thoughts into speech

233
Q

Where is Broca’s area located?

A

found near the part of the motor cortex controlling the face

234
Q

What is the function of Broca’s area?

A

responsible for generation of motor output needed for language communication

235
Q

What are aphasias?

A

language disorders caused by damage to the relevant brain areas

236
Q

If Wernicke’s area is damaged, what happens?

A

person’s speech is rapid and fluid but lacks meaning

237
Q

What hemisphere is used for spatial reasoning in most right handed people?

A

the right hemisphere

238
Q

Which hemisphere is involved in musical ability?

A

right hemisphere

239
Q

Damage to the inferior temporal cortex results in

A

the loss of the ability to recognize faces, a condition called prosopagnosia

240
Q

Which hemisphere is important for the consolidation of memories of nonverbal experiences?

A

the right hemisphere

241
Q

What are two examples of synaptic plasticity?

A

long-term potentiation (LTP) and long-term depression (LTD)

242
Q

What are the effects of Alzheimer disease?

A

memory and thought processes of the brain become dysfunctional

243
Q

What are the two hypotheses about the origin of Alzheimer disease?

A

nerve cells in the brain are killed from the outside in; nerve cells in the brain are killed on the inside out

244
Q

What happens in the first hypothesis about Alzheimer disease?

A

proteins called beta-amyloid form aggregates and fill the brain and kill nerve cells

245
Q

What happens in the second hypothesis about Alzheimer disease?

A

nerve cells are killed by an abnormal form of tau protein, which tangle up and interfere with the normal function of nerve cells

246
Q

What are meninges?

A

layers of membrane that protect the spinal cord

247
Q

What are the two zones in the spinal cord?

A

inner zone of grey matter; outer zone of white matter

248
Q

Describe the inner zone of the spinal cord. (2)

A

gray matter; consists of cell bodies of interneurons/motor neurons/neuroglia

249
Q

Describe the outer zone of the spinal cord. (2)

A

white matter; contains cables of sensory axons in the dorsal columns and motor axons in the ventral columns

250
Q

What are reflexes?

A

sudden, involuntary movement of muscles

251
Q

Which structure is responsible for reflexes?

A

spinal cord

252
Q

What happens in monosynaptic reflex arcs?

A

sensory nerve cell makes synaptic contact directly with a motor neuron in the spinal cord whose axon travels directly back to the muscle

253
Q

Most reflexes in vertebrates, however, involve what?

A

a single connecting interneuron between the sensory neuron and a motor neuron

254
Q

What does the PNS consist of?

A

nerves (collections of axons) and ganglia

255
Q

What are ganglia?

A

aggregations of neuron cell bodies located outside the CNS

256
Q

What is the dorsal root?

A

the point where the axons of sensory neurons enter the dorsal surface of the spinal cord

257
Q

What is the ventral root?

A

the point where motor axons leave from the ventral surface of the spinal cord

258
Q

What is the dorsal root ganglia?

A

where the cell bodies of sensory neurons are grouped together

259
Q

Where are the cell bodies of somatic motor neurons located?

A

within the spinal cord, NOT in ganglia

260
Q

What are the two divisions of the autonomic nervous system?

A

sympathetic and parasympathetic divisions

261
Q

The autonomic nervous system is composed of (3)

A

the sympathetic division, parasympathetic division, medulla oblongata

262
Q

How are the sympathetic and parasympathetic divisions similar?

A

both have efferent motor pathway involving two neurons

263
Q

The first neuron of the efferent motor pathway in the sympathetic and para sympathetic divisions is located in / its name (2)

A

the CNS and sends an axon to an autonomic ganglion; called the preganglionic neuron

264
Q

The preganglionic neuron uses what neurotransmitter?

A

acetylcholine

265
Q

The second neuron of the efferent motor pathway in the sympathetic and para sympathetic divisions is located in / its name (2)

A

autonomic ganglion and sends it axon to synapse with a smooth muscle/cardiac muscle/gland cell; called the postganglionic neuron

266
Q

The postganglionic neuron uses what neurotransmitter?

A

In the parasympathetic division, acetylcholine; in the sympathetic division, norepinephrine

267
Q

The preganglionic neurons of the sympathetic nervous system originate in what part of the spinal cord?

A

thoracic and lumbar regions of the spinal cord

268
Q

What is the sympathetic chain of ganglia?

A

the two parallel chains of ganglia immediately outside the spinal cord

269
Q

The sympathetic chain of ganglia contains what?

A

the cell bodies of postganglionic cells

270
Q

Where do preganglionic parasympathetic neurons originate in?

A

brain and sacral regions of the spinal cord

271
Q

Where do preganglionic parasympathetic axons terminate?

A

near or within internal organs

272
Q

How do preganglionic parasympathetic neurons regulate internal organs?

A

by releasing acetylcholine at their synapses

273
Q

Which system (sympathetic/parasympathetic) is the one used for fight/flight?

A

sympathetic - fight/flight; parasympathetic - resting

274
Q

What effect does acetylcholine have on heart rate?

A

slows heart rate

275
Q

The acetylcholine receptor in the heart is a member of a class of receptors called

A

G protein-coupled receptors

276
Q

How do G proteins mediate sympathetic nerve effects?

A

stimulation by norepinephrine from sympathetic nerve endings and epinephrine from eh adrenal medulla require G proteins to activate the target cells

Biology 2312 (11 decks)

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