Chapter 12 Flashcards
1
Q
Which nervous system is composed of the brain and spinal cord?
A
The central nervous system (CNS) is composed of the brain and spinal cord.
2
Q
Which system controls the skeletal muscles?
A
The somatic nervous system controls the skeletal muscles.
3
Q
What are the differences between afferent, efferent, autonomic, and peripheral functions?
A
Afferent pathways carry sensory information to the CNS, while efferent pathways carry motor commands away from the CNS. The autonomic nervous system regulates involuntary functions, and the peripheral nervous system connects the CNS to limbs and organs.
4
Q
How does motor information get to peripheral effectors?
A
Motor information travels through motor neurons from the CNS to peripheral effectors.
5
Q
Which nerves connect to the spine vs brain?
A
Spinal nerves connect to the spine, while cranial nerves connect to the brain.
6
Q
What comprises the axoplasm of the axon?
A
The axoplasm consists of cytoplasm within the axon, containing organelles and proteins.
7
Q
What happens when the axoplasm is blocked?
A
Blocking the axoplasm disrupts the transport of materials along the axon.
8
Q
What is the structural classification for neurons?
A
Neurons can be classified structurally as unipolar, bipolar, multipolar, or anaxonic.
9
Q
What is the cytoplasm of a neuron called?
A
The cytoplasm of a neuron is called the perikaryon.
10
Q
What are Nissl bodies?
A
Nissl bodies are rough endoplasmic reticulum and ribosomes found in the cell body of neurons.
11
Q
How do axons connect to the soma?
A
Axons connect to the soma at the axon hillock.
12
Q
What are axon branches called?
A
Axon branches are called axon collaterals.
13
Q
How are axons terminated?
A
Axons terminate at synaptic terminals.
14
Q
Where does intercellular communication between a neuron and another cell occur?
A
Intercellular communication occurs at synapses.
15
Q
How does the rabies virus reach the CNS?
A
The rabies virus travels retrogradely along axons to reach the CNS.
16
Q
What are the structural and functional variations between anaxonic, unipolar, bipolar, tripolar, and multipolar neurons?
A
Anaxonic neurons have no distinct axon, unipolar neurons have one process, bipolar neurons have two processes, tripolar neurons have three processes, and multipolar neurons have multiple processes.
17
Q
What is the most numerous type of neuron in the CNS?
A
The most numerous type of neuron in the CNS is the multipolar neuron.
18
Q
What are the functional variations of internoceptors, exteroceptors, and proprioceptors?
A
Internoceptors detect internal stimuli, exteroceptors detect external stimuli, and proprioceptors provide information about body position and movement.
19
Q
What is the plasma membrane of an axon?
A
The plasma membrane of an axon is called the axolemma.
20
Q
What is the functional unit of the nervous system?
A
The functional unit of the nervous system is the neuron.
21
Q
What is the most common neuron of the nervous system?
A
The most common neuron in the nervous system is the multipolar neuron.
22
Q
Do neurons undergo cell division? Why or why not?
A
Neurons generally do not undergo cell division due to their specialized function and structure.
23
Q
What happens upon Wallerian degeneration?
A
Wallerian degeneration occurs when a nerve fiber is damaged, leading to degeneration of the axon distal to the injury.
24
Q
What is the function and quantity of neuroglia?
A
Neuroglia support, protect, and maintain homeostasis for neurons; they outnumber neurons significantly.
25
What are the types of neuroglia?
Types of neuroglia include astrocytes, satellite cells, oligodendrocytes, microglia, and ependymal cells.
26
How is the myelin sheath formed?
The myelin sheath is formed by oligodendrocytes in the CNS and Schwann cells in the PNS.
27
How are the neurilemma of axons in the peripheral nervous system formed?
The neurilemma is formed by Schwann cells wrapping around the axon.
28
What happens upon damage to ependymal cells?
Damage to ependymal cells can disrupt the production and circulation of cerebrospinal fluid.
29
What happens when pressure is applied to neural tissue?
Applying pressure to neural tissue can disrupt blood flow and neuronal function.
30
How do Schwann cells participate in the repair of damaged nerves?
Schwann cells help repair damaged nerves by forming a regeneration tube.
31
What is the space between Schwann cells called?
The space between Schwann cells is called the internodal region.
32
What is the difference between gray and white matter composition?
Gray matter contains neuronal cell bodies, while white matter contains myelinated axons.
33
What are the causes of demyelination?
Demyelination can be caused by autoimmune diseases, infections, and genetic disorders.
34
What happens during the establishment of a neuron's resting membrane potential?
During resting membrane potential establishment, sodium ions are pumped out and potassium ions are pumped in, typically in a 3:2 ratio.
35
What are active, gated, and leak channels?
Active channels require energy to transport ions, gated channels open in response to stimuli, and leak channels allow ions to pass freely.
36
What are the effects of open sodium channels in the axon membrane?
Open sodium channels lead to depolarization of the neuron.
37
Where are voltage-gated channels found?
Voltage-gated channels are found along the axon membrane.
38
What is the function of the sodium-potassium ion exchange pump?
The sodium-potassium pump maintains the resting membrane potential by moving sodium out and potassium into the cell.
39
What are chemically gated, voltage-gated, and mechanically gated channels?
Chemically gated channels open in response to neurotransmitters, voltage-gated channels open in response to changes in membrane potential, and mechanically gated channels open in response to physical deformation.
40
What happens when chemically gated, voltage-gated, or mechanically gated channels are blocked?
Blocking these channels prevents the normal flow of ions, disrupting neuronal signaling.
41
What contributes to creating the resting membrane potential of a neuron?
The resting membrane potential is created by the distribution of ions, particularly sodium and potassium, across the membrane.
42
What are the effects of sodium-potassium pumps in the plasma membrane functional failure?
Failure of sodium-potassium pumps can lead to depolarization and loss of resting potential.
43
What are graded potentials?
Graded potentials are changes in membrane potential that vary in size and can lead to action potentials.
44
How do ions move across the plasma membrane?
Ions move across the plasma membrane through channels and pumps.
45
What is the difference between activation gate and inactivation gate?
The activation gate opens in response to depolarization, while the inactivation gate closes to stop ion flow.
46
If acetylcholine (ACh) causes inhibition of a postsynaptic neuron, to what type of membrane channel did the ACh bind?
ACh binds to chemically gated channels to cause inhibition.
47
What is the difference between current, action potential, and electrochemical gradient?
Current refers to the flow of electric charge, action potential is a rapid change in membrane potential, and electrochemical gradient is the difference in ion concentration across a membrane.
48
What are the effects of depolarization, hyperpolarization, polarization, and repolarization on neurons?
Depolarization makes the inside of the neuron more positive, hyperpolarization makes it more negative, polarization refers to the resting state, and repolarization returns the membrane potential to resting state.
49
What is the equilibrium potential of potassium vs sodium?
The equilibrium potential for potassium is typically around -90 mV, while for sodium it is around +60 mV.
50
What is the all-or-none principle?
The all-or-none principle states that an action potential occurs fully or not at all.
51
How would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactivate?
If sodium channels failed to inactivate, the absolute refractory period would be prolonged, preventing subsequent action potentials.
52
How would a chemical that prevents the opening of voltage-regulated Na+ channels affect the function of a neuron?
It would prevent depolarization and inhibit action potential generation.
53
What is a threshold stimulus?
A threshold stimulus is the minimum level of stimulus required to trigger an action potential.
54
What are the differences between spatial, saltatory, and divergent continuous propagation?
Spatial propagation involves multiple neurons, saltatory propagation occurs along myelinated axons, and divergent propagation spreads signals to multiple targets.
55
What conditions influence the time necessary for a nerve impulse to be transmitted?
Factors include axon diameter, myelination, and temperature.
56
What are the structures and functions of type A, B, C, D, and E nerve fibers?
Type A fibers are large and myelinated for fast conduction; type B fibers are medium and myelinated; type C fibers are small and unmyelinated for slow conduction.
57
What conditions affect the rate of impulse conduction?
The rate of impulse conduction is affected by myelination, axon diameter, and temperature.
58
What are relative refractory, absolute refractory, resting, lag, and stationary periods?
Relative refractory period is when a stronger stimulus can initiate an action potential; absolute refractory period is when no stimulus can initiate one; resting is the stable state; lag is the time after an action potential; stationary is when the membrane potential is stable.
59
How does myelin affect action potential?
Myelin increases the speed of action potential propagation through saltatory conduction.
60
What are the effects of neurotransmitters on presynaptic vs postsynaptic neurons?
Neurotransmitters can excite or inhibit postsynaptic neurons, while presynaptic neurons release them.
61
Which type of synapse is most common in the nervous system?
Chemical synapses are the most common type in the nervous system.
62
Which ion triggers the release of acetylcholine into the synaptic cleft?
Calcium ions trigger the release of acetylcholine.
63
What is the function of cholinergic vs adrenergic synapses?
Cholinergic synapses use acetylcholine, while adrenergic synapses use norepinephrine.
64
What are the differences between electrical and chemical synapses?
Electrical synapses allow direct ion flow between cells, while chemical synapses use neurotransmitters.
65
What is synaptic delay vs synaptic diffusion?
Synaptic delay is the time it takes for neurotransmitter release and binding, while synaptic diffusion is the movement of neurotransmitters across the synaptic cleft.
66
What is the role of glutamate?
Glutamate is the primary excitatory neurotransmitter in the CNS.
67
What are the differences between dopamine, norepinephrine, and serotonin?
Dopamine is involved in reward and movement, norepinephrine in arousal and alertness, and serotonin in mood regulation.
68
What is GABA?
GABA is the primary inhibitory neurotransmitter in the brain.
69
Which neurotransmitter is a dissolved gas?
Nitric oxide is a neurotransmitter that is a dissolved gas.
70
Which neurotransmitters bind to G-protein coupled receptors?
Neurotransmitters like norepinephrine and serotonin bind to G-protein coupled receptors.
71
How is cyclic AMP synthesized?
Cyclic AMP is synthesized from ATP by the enzyme adenylate cyclase.
72
What is the function of cyclic AMP?
Cyclic AMP acts as a second messenger in signal transduction pathways.
73
When does a postsynaptic neuron have an excitatory postsynaptic potential (EPSP)?
A postsynaptic neuron has an EPSP when it is depolarized by excitatory neurotransmitters.
74
What are IPSPs (inhibitory postsynaptic potentials)?
IPSPs are hyperpolarizations that decrease the likelihood of an action potential.
75
Where do EPSPs and IPSPs integrate?
EPSPs and IPSPs integrate at the axon hillock of the postsynaptic neuron.
76
What is the difference between spatial summation and temporal summation?
Spatial summation occurs when multiple synapses are activated simultaneously, while temporal summation occurs when a single synapse is activated repeatedly over time.
77
What happens when a neuron's membrane potential shifts closer to threshold?
When a neuron's membrane potential shifts closer to threshold, it increases the likelihood of generating an action potential.
78
What is presynaptic facilitation vs spatial facilitation?
Presynaptic facilitation enhances neurotransmitter release, while spatial facilitation involves multiple inputs contributing to depolarization.
79
Which nervous system is composed of the brain and spinal cord?
The central nervous system (CNS) is composed of the brain and spinal cord.
80
Which system controls the skeletal muscles?
The somatic nervous system controls the skeletal muscles.
81
What are the differences between afferent, efferent, autonomic, and peripheral functions?
Afferent pathways carry sensory information to the CNS, while efferent pathways carry motor commands away from the CNS. The autonomic nervous system regulates involuntary functions, and the peripheral nervous system connects the CNS to limbs and organs.
82
How does motor information get to peripheral effectors?
Motor information travels through motor neurons from the CNS to peripheral effectors.
83
Which nerves connect to the spine vs brain?
Spinal nerves connect to the spine, while cranial nerves connect to the brain.
84
What comprises the axoplasm of the axon?
The axoplasm consists of cytoplasm within the axon, containing organelles and proteins.
85
What happens when the axoplasm is blocked?
Blocking the axoplasm disrupts the transport of materials along the axon.
86
What is the structural classification for neurons?
Neurons can be classified structurally as unipolar, bipolar, multipolar, or anaxonic.
87
What is the cytoplasm of a neuron called?
The cytoplasm of a neuron is called the perikaryon.
88
What are Nissl bodies?
Nissl bodies are rough endoplasmic reticulum and ribosomes found in the cell body of neurons.
89
How do axons connect to the soma?
Axons connect to the soma at the axon hillock.
90
What are axon branches called?
Axon branches are called axon collaterals.
91
How are axons terminated?
Axons terminate at synaptic terminals.
92
Where does intercellular communication between a neuron and another cell occur?
Intercellular communication occurs at synapses.
93
How does the rabies virus reach the CNS?
The rabies virus travels retrogradely along axons to reach the CNS.
94
What are the structural and functional variations between anaxonic, unipolar, bipolar, tripolar, and multipolar neurons?
Anaxonic neurons have no distinct axon, unipolar neurons have one process, bipolar neurons have two processes, tripolar neurons have three processes, and multipolar neurons have multiple processes.
95
What is the most numerous type of neuron in the CNS?
The most numerous type of neuron in the CNS is the multipolar neuron.
96
What are the functional variations of internoceptors, exteroceptors, and proprioceptors?
Internoceptors detect internal stimuli, exteroceptors detect external stimuli, and proprioceptors provide information about body position and movement.
97
What is the plasma membrane of an axon?
The plasma membrane of an axon is called the axolemma.
98
What is the functional unit of the nervous system?
The functional unit of the nervous system is the neuron.
99
What is the most common neuron of the nervous system?
The most common neuron in the nervous system is the multipolar neuron.
100
Do neurons undergo cell division? Why or why not?
Neurons generally do not undergo cell division due to their specialized function and structure.
101
What happens upon Wallerian degeneration?
Wallerian degeneration occurs when a nerve fiber is damaged, leading to degeneration of the axon distal to the injury.
102
What is the function and quantity of neuroglia?
Neuroglia support, protect, and maintain homeostasis for neurons; they outnumber neurons significantly.
103
What are the types of neuroglia?
Types of neuroglia include astrocytes, satellite cells, oligodendrocytes, microglia, and ependymal cells.
104
How is the myelin sheath formed?
The myelin sheath is formed by oligodendrocytes in the CNS and Schwann cells in the PNS.
105
How are the neurilemma of axons in the peripheral nervous system formed?
The neurilemma is formed by Schwann cells wrapping around the axon.
106
What happens upon damage to ependymal cells?
Damage to ependymal cells can disrupt the production and circulation of cerebrospinal fluid.
107
What happens when pressure is applied to neural tissue?
Applying pressure to neural tissue can disrupt blood flow and neuronal function.
108
How do Schwann cells participate in the repair of damaged nerves?
Schwann cells help repair damaged nerves by forming a regeneration tube.
109
What is the space between Schwann cells called?
The space between Schwann cells is called the internodal region.
110
What is the difference between gray and white matter composition?
Gray matter contains neuronal cell bodies, while white matter contains myelinated axons.
111
What are the causes of demyelination?
Demyelination can be caused by autoimmune diseases, infections, and genetic disorders.
112
What happens during the establishment of a neuron's resting membrane potential?
During resting membrane potential establishment, sodium ions are pumped out and potassium ions are pumped in, typically in a 3:2 ratio.
113
What are active, gated, and leak channels?
Active channels require energy to transport ions, gated channels open in response to stimuli, and leak channels allow ions to pass freely.
114
What are the effects of open sodium channels in the axon membrane?
Open sodium channels lead to depolarization of the neuron.
115
Where are voltage-gated channels found?
Voltage-gated channels are found along the axon membrane.
116
What is the function of the sodium-potassium ion exchange pump?
The sodium-potassium pump maintains the resting membrane potential by moving sodium out and potassium into the cell.
117
What are chemically gated, voltage-gated, and mechanically gated channels?
Chemically gated channels open in response to neurotransmitters, voltage-gated channels open in response to changes in membrane potential, and mechanically gated channels open in response to physical deformation.
118
What happens when chemically gated, voltage-gated, or mechanically gated channels are blocked?
Blocking these channels prevents the normal flow of ions, disrupting neuronal signaling.
119
What contributes to creating the resting membrane potential of a neuron?
The resting membrane potential is created by the distribution of ions, particularly sodium and potassium, across the membrane.
120
What are the effects of sodium-potassium pumps in the plasma membrane functional failure?
Failure of sodium-potassium pumps can lead to depolarization and loss of resting potential.
121
What are graded potentials?
Graded potentials are changes in membrane potential that vary in size and can lead to action potentials.
122
How do ions move across the plasma membrane?
Ions move across the plasma membrane through channels and pumps.
123
What is the difference between activation gate and inactivation gate?
The activation gate opens in response to depolarization, while the inactivation gate closes to stop ion flow.
124
If acetylcholine (ACh) causes inhibition of a postsynaptic neuron, to what type of membrane channel did the ACh bind?
ACh binds to chemically gated channels to cause inhibition.
125
What is the difference between current, action potential, and electrochemical gradient?
Current refers to the flow of electric charge, action potential is a rapid change in membrane potential, and electrochemical gradient is the difference in ion concentration across a membrane.
126
What are the effects of depolarization, hyperpolarization, polarization, and repolarization on neurons?
Depolarization makes the inside of the neuron more positive, hyperpolarization makes it more negative, polarization refers to the resting state, and repolarization returns the membrane potential to resting state.
127
What is the equilibrium potential of potassium vs sodium?
The equilibrium potential for potassium is typically around -90 mV, while for sodium it is around +60 mV.
128
What is the all-or-none principle?
The all-or-none principle states that an action potential occurs fully or not at all.
129
How would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactivate?
If sodium channels failed to inactivate, the absolute refractory period would be prolonged, preventing subsequent action potentials.
130
How would a chemical that prevents the opening of voltage-regulated Na+ channels affect the function of a neuron?
It would prevent depolarization and inhibit action potential generation.
131
What is a threshold stimulus?
A threshold stimulus is the minimum level of stimulus required to trigger an action potential.
132
What are the differences between spatial, saltatory, and divergent continuous propagation?
Spatial propagation involves multiple neurons, saltatory propagation occurs along myelinated axons, and divergent propagation spreads signals to multiple targets.
133
What conditions influence the time necessary for a nerve impulse to be transmitted?
Factors include axon diameter, myelination, and temperature.
134
What are the structures and functions of type A, B, C, D, and E nerve fibers?
Type A fibers are large and myelinated for fast conduction; type B fibers are medium and myelinated; type C fibers are small and unmyelinated for slow conduction.
135
What conditions affect the rate of impulse conduction?
The rate of impulse conduction is affected by myelination, axon diameter, and temperature.
136
What are relative refractory, absolute refractory, resting, lag, and stationary periods?
Relative refractory period is when a stronger stimulus can initiate an action potential; absolute refractory period is when no stimulus can initiate one; resting is the stable state; lag is the time after an action potential; stationary is when the membrane potential is stable.
137
How does myelin affect action potential?
Myelin increases the speed of action potential propagation through saltatory conduction.
138
What are the effects of neurotransmitters on presynaptic vs postsynaptic neurons?
Neurotransmitters can excite or inhibit postsynaptic neurons, while presynaptic neurons release them.
139
Which type of synapse is most common in the nervous system?
Chemical synapses are the most common type in the nervous system.
140
Which ion triggers the release of acetylcholine into the synaptic cleft?
Calcium ions trigger the release of acetylcholine.
141
What is the function of cholinergic vs adrenergic synapses?
Cholinergic synapses use acetylcholine, while adrenergic synapses use norepinephrine.
142
What are the differences between electrical and chemical synapses?
Electrical synapses allow direct ion flow between cells, while chemical synapses use neurotransmitters.
143
What is synaptic delay vs synaptic diffusion?
Synaptic delay is the time it takes for neurotransmitter release and binding, while synaptic diffusion is the movement of neurotransmitters across the synaptic cleft.
144
What is the role of glutamate?
Glutamate is the primary excitatory neurotransmitter in the CNS.
145
What are the differences between dopamine, norepinephrine, and serotonin?
Dopamine is involved in reward and movement, norepinephrine in arousal and alertness, and serotonin in mood regulation.
146
What is GABA?
GABA is the primary inhibitory neurotransmitter in the brain.
147
Which neurotransmitter is a dissolved gas?
Nitric oxide is a neurotransmitter that is a dissolved gas.
148
Which neurotransmitters bind to G-protein coupled receptors?
Neurotransmitters like norepinephrine and serotonin bind to G-protein coupled receptors.
149
How is cyclic AMP synthesized?
Cyclic AMP is synthesized from ATP by the enzyme adenylate cyclase.
150
What is the function of cyclic AMP?
Cyclic AMP acts as a second messenger in signal transduction pathways.
151
When does a postsynaptic neuron have an excitatory postsynaptic potential (EPSP)?
A postsynaptic neuron has an EPSP when it is depolarized by excitatory neurotransmitters.
152
What are IPSPs (inhibitory postsynaptic potentials)?
IPSPs are hyperpolarizations that decrease the likelihood of an action potential.
153
Where do EPSPs and IPSPs integrate?
EPSPs and IPSPs integrate at the axon hillock of the postsynaptic neuron.
154
What is the difference between spatial summation and temporal summation?
Spatial summation occurs when multiple synapses are activated simultaneously, while temporal summation occurs when a single synapse is activated repeatedly over time.
155
What happens when a neuron's membrane potential shifts closer to threshold?
When a neuron's membrane potential shifts closer to threshold, it increases the likelihood of generating an action potential.
156
What is presynaptic facilitation vs spatial facilitation?
Presynaptic facilitation enhances neurotransmitter release, while spatial facilitation involves multiple inputs contributing to depolarization.
