Chapter 12 Questions Based On Objectives Flashcards

1
Q

What are the two main subdivisions of the Nervous System?

A

2 parts
Central nervous system
Peripheral Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the Central Nervous System consist of?

A

The Brain and the Spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much of the body mass is the nervous system?

A

3%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The Nervous system is often described as?

A

The smallest and most complex out of the 11 systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the spinal cord connect to the brain anatomically?

A

through the foramen magnum of the occipital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What composes the Peripheral Nervous System?

A

All nervous tissue outside the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many cranial nerves are there?

A

12 pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How many spinal nerves are there?

A

31 pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does ganglia mean?

A

Swelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define sensory receptor

A

The term sensory receptor refers to a nervous system structure that monitors changes in the external or internal environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Definition of ganglia

A

Small masses of nervous, consisting neuron cell body that are located outside of the brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where are the enteric plexus located?

A

wall of organs of the GI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the enteric plexus do

A

Help regulate the digestive system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the three types of sensory receptors?

A

Touch receptor
Photo receptor
Olfactory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the two sub-divisions of the PNS?

A

Somatic and Autonomic Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where does the SNS convey information to?

A

conveys output from the CNS to skeletal muscles only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where does the output of the ANS convey its output from? And to what 3 specific places?

A

Conveys output from the CNS to smooth muscle, cardiac muscle, and glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Is the PNS voluntary or involuntary?

A

Voluntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Is the ANS voluntary or involuntary?

A

Involuntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the two main branches of the ANS

A

Sympathetic and Parasympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Is the fight-or-flight response the sympathetic or parasympathetic nervous system?

A

Sympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Is the rest-and-digest response the sympathetic or parasympathetic nervous system?

A

parasympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are the sub-divisions of the PNS divided?

A

The sensory or afferent division
The motor or efferent division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The motor or efferent division of the PNS conveys output from the CNS to _______

A

Effectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The sensory or afferent division of the PNS conveys input into the CNS from____________ in the body

A

sensory receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the three basic functions of the nervous system?

A

Sensory function
Integrative functions
Motor functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Out of the three functions of the nervous system, the sensory function can be described as ___________
Input or Processes or Output

A

Input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Out of the three functions of the nervous system, the Integrative function can be described as ___________
Input or Processes or Output

A

Processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Out of the three functions of the nervous system, the motor function can be described as ___________
Input or Processes or Output

A

Output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the functions of the sensory receptors?

A

Sensory receptor detects internal stimuli.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How do the sensory receptors send messages to the brain?

A

Sensory information is carried into the brain and spinal cord through cranial and spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the functions of the Integrative part of the nervous system?

A

Processes sensory info by analyzing it and making decision for appropriate response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the functions of the motor part of the nervous system?

A

Once the info is integrated, the nervous system sends the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does the nervous system send motor signals?

A

through cranial and spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the two types of cells that comprise the nervous tissue?

A

Neuroglia
&
Neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Neurons possess electrical excitability, which means?

A

the ability to respond to a stimulus and convert it into an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is an action potential

A

electrical signal that travels through the membrane of the neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What does the Nissl Body of a neuron do?

A

Produce protein for the neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the Initial segment of a neuron?

A

Part of the axon closest to axon hillock.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Where is the trigger zone of a neuron?

A

Location where nerve impulses arise.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is Axon collateral?

A

side branches of an axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is Varicosities?

A

String of swollen terminals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is a Multipolar Neurons

A

Several dendrites and only one axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is a bipolar neuron?

A

one dendrite and one axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is a unipolar neuron?

A

dendrites and fused axon (continuous process)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Where do you find multipolar neuron?

A

Most neurons in the brain and spinal cord, and all of motor neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Where do you find bipolar neurons?

A

Retina of eye, inner ear, and olfactory area of brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Where do you find unipolar neurons?

A

Dendrites are used for sensory receptors
Located in the ganglia of spinal and cranial nerves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Functional Classification of Sensory Neurons

A

Contain sensory receptors at distal ends or after sensory receptors.
Most are unipolar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Functional Classification of Motor Neurons

A

Convey action potentials away from CNS to effectors in the peripheral nervous system (PNS).
Multipolar in structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Functional Classification of interneurons

A

In the CNS, located between sensory and motor neurons.
Processes information from sensory neurons and then sends a motor response by activating motor neurons.
Most are multipolar in structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

True/False
Neuroglia cells generate or propagate action potentials, but they can multiply.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Neuroglia cells can ________ to fill in spaces formerly occupied by degenerated neurons.

A

Multiply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the 6 different cells of the neuroglia?

A

Satellite Cells
Schwann Cells
Ependymal cells
Microglia
Oligodendrocytes
Astrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the function of Astrocytes?

A

Structurally support neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the function of Oligodendrocytes?

A

Forms and maintains myelin sheath around CNS axons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is the myelin sheath?

A

Are a multi-layer lipid and protein covering some axons, which insulates them and speeds up nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is the function of Microglia?

A

Remove cellular debris, phagocytize microbes, damaged nerve tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the function of Ependymal cells?

A

Produce, monitor, and assist the circulation of cerebrospinal fluid.
&
Form blood-cerebrospinal fluid barrier.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the function of Schwann cells?

A

Form myelin sheath around axons
&
Participate in axon regeneration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the function of Satellite cells?

A

Provides structural support.
&
Regulate the exchange of materials between neuronal cell bodies and interstitial fluid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Axons surrounded by myelin sheaths are said to be _________, and those without it are __________.

A

myelinated
&
unmyelinated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What are the functions of Neurolemma?

A

Aids in the regeneration of axons by forming a regeneration tube.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What are the Nodes of Ranvier?

A

Gaps in the myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What are Clusters of Neuronal Cell Bodies called in the CNS?

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are Clusters of Neuronal Cell Bodies called in the PNS?

A

Ganglion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are Bundles of Axons called in the CNS?

A

Tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the function of tract axons?

A

Interconnects neurons in the spinal cord and brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are Bundles of Axons called in the PNS?

A

Nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is white matter composed of?

A

Composed of myelinated axons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is Grey matter composed of?

A

Composed of unmyelinated axons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Which type of matter contains blood vessels?

A

White & Grey Matter

73
Q

In the spinal cord, ______ matter surrounds a _______ matter core.

A

white
&
Gray

74
Q

In the brain, _______matter covers the surface of the cerebrum and cerebellum.

A

Gray

75
Q

Which type of matter contains neuronal bodies, dendrites, axon terminals, and neuroglia?

A

Gray

76
Q

When are graded potentials used?

A

For short-distance communication.

77
Q

What are the two types of action potentials?

A

Muscle Action Potential
Nerve Action Potential

78
Q

Muscle Action Potential occurs where?

A

occurs in muscle fibers

79
Q

Nerve Action Potential occurs in?

A

in a neuron

80
Q

What are the two basic features of the plasma membrane of excitable cells?

A

Existence of resting membrane potential Presence of specific types of ion channels

81
Q

What are the 4 types of ion channels

A

Leak Channels
Ligand-gated Channels
Mechanically-gated Channels
Voltage-gated Channels

82
Q

What is a Leak Channel?

A

Gated channels that randomly open and closes.

83
Q

Where do you find Leak Channels?

A

All cells, dendrites, cell bodies, and axons of all types of neurons.

84
Q

What are Ligand-gated Channels?

A

Open in response to binding of ligand (chemical) stimulus.

85
Q

Where do you find Ligand-gated Channels?

A

Dendrites of sensory receptors such as pain receptors, dendrites and cell bodies of interneurons and motor neurons.

86
Q

What are Mechanically-gated Channels?

A

Open in response to mechanical stimulus (vibration), such as touch, pressure, vibration, tissue stretching.

87
Q

Where do you find Mechanically-gated Channels?

A

Dendrites of sensory neurons such as touch receptors, pressure receptors, pain receptors.

88
Q

What are Voltage-gated Channels?

A

Open in response to change in membrane potential (voltage stimulus).

89
Q

Where do you find Voltage-gated Channels?

A

Axons of all types of neurons.

90
Q

What is Resting Membrane Potential?

A

A cell exhibiting a membrane potential is said to be polarized (cytosol is more negative and extracellular fluid is more positive).

91
Q

What are the three Factors leading to a membrane potential?

A
  1. Unequal distribution of ions in the extracellular fluid and cytosol.
  2. Inability of most anions to leave the cell.
  3. Electrogenic nature of Na+-K+ ATPases.
92
Q

What is a Graded Potential?

A

arises due to the small deviation from resting membrane potential that makes a membrane more (more negative) or less (less negative inside) polarized.

93
Q

What are the two types of graded potentials?

A

Hyperpolarizing Graded Potential
Depolarizing Graded Potential

94
Q

What is a Hyperpolarizing Graded Potential

A

When the response makes a membrane more polarized (more negative inside).

95
Q

What is a Depolarizing Graded Potential?

A

When the response makes a membrane less polarized (less negative inside).

96
Q

What is Decremental Conduction?

A

Graded potentials die out as they spread along the membrane.

97
Q

What is Summation?

A

When graded potentials add together, potentials can become stronger and last longer.

98
Q

What is Action potential (Impulse)?

A

sequence of rapidly occurring events that decrease and reverse the membrane potential and restores it to a resting state.

99
Q

What are the 2 main phases of the generation of the action potential?

A

Depolarizing Phase
Repolarizing Phase

100
Q

What is the Depolarizing Phase?

A

the negative membrane becomes less negative, reaches zero, then positive.

101
Q

What is the Repolarizing Phase?

A

membrane potential is restored to resting state of -70 mV.

102
Q

What is the After-hyperpolarizing phase?

A

After repolarizing, this event may occur, in which the membrane temporarily becomes more negative (< -70mV).

103
Q

What is the threshold?

A

Action potential occurs in the axon of a neuron when depolarization reaches a certain level (~ -55mV).

104
Q

What is Subthreshold Stimulus

A

Weak depolarization that does not cause an action potential.

105
Q

What is Threshold Stimulus?

A

Stimulus strong enough to depolarize the membrane to the threshold.

106
Q

What is Suprathreshold Stimulus?

A

– stimulus strong enough to depolarize above the threshold.

107
Q

What are the 4 phases of an action potential?

A
  1. Depolarizing Phase
  2. Repolarizing Phase
  3. After-hyperpolarizing Phase
  4. Refractory Period
108
Q

What is the depolarizing phase of an action potential?

A

the membrane becomes less negative -> positive.

109
Q

What is the Repolarizing phase of an action potential?

A

K+ outflow causes membrane to go back to negative (-70 mV).

110
Q

What is the After-hyperpolarizing Phase

A

too much K+ may cause the membrane to be less than -70 mV.

111
Q

What is the Refractory Period?

A

A cell cannot generate another action potential.

112
Q

What are the two types of Refractory Periods?

A

Absolute Refractory Period
Relative Refractory Period

113
Q

What is the Absolute Refractory Period?

A

Even a strong stimulus cannot cause another action potential.

114
Q

What is the Relative Refractory Period?

A

A second action potential can be produced only by a larger-than-normal stimulus.

115
Q

What is Propagation of Action Potentials?

A

action potentials keep its strength as it spreads along the membrane. Action potentials regenerate over and over at adjacent regions of the membrane.

116
Q

What is Continuous Conduction?

A
  1. Step-by-step depolarization and repolarization of adjacent regions of the plasma membrane.
  2. Ions flow through their voltage-gated channels.
  3. Occurs in unmyelinated axons and muscle fibres.
117
Q

What is Saltatory Conduction?

A

Occurs in myelinated axons (due to uneven distribution of voltage-gated channels).
Gated channels are present in the nodes of Ranvier (no axolemma).
Gates only open at nodes. Thus, more efficiently, less ATP is required to maintain Na+ and K+ concentration.

118
Q

What are the 3 Factors Affecting the Speed of Propagation?

A
  1. Amount of myelination
  2. Axon Diameter
  3. Temperature
119
Q

How does the amount of myelination affect speed or propagation?

A

More myelin = faster propagation.

120
Q

How does the axon diameter affect speed or propagation?

A

Larger diameters = faster propagation due to large surface area.

121
Q

How does temperature affect speed or propagation?

A

Lower temperature = slower propagation.

122
Q

The resting membrane potential arises from What three major factors?

A
  1. Unequal distribution of ions in the ECF and cytosol.
  2. Inability of most anions to leave the cell.
  3. Electrogenic nature of the Na+–K+ ATPases.
123
Q

What does the factor of Unequal distribution of ions in the ECF and cytosol, mean in terms of resting membrane?

A

As more and more positive potassium ions exit, the inside of the membrane becomes increasingly negative, and the outside of the membrane becomes increasingly positive.

124
Q

What does the factor of the Inability of most anions to leave the cell, mean in terms of resting membrane potential?

A

Most anions inside the cell are not free to leave. They cannot follow the K+ out of the cell because they are attached to nondiffusible molecules such as ATP and large proteins.

125
Q

What does the factor Electrogenic nature of the Na+–K+ ATPases mean in terms of resting membrane potential?

A

Since these pumps remove more positive charges from the cell than they bring into the cell, they are electrogenic, which means they contribute to the negativity of the resting membrane potential.

126
Q

What is a Presynaptic Neuron?

A

– nerve cell that carries an impulse towards the synapse. It sends a signal.

127
Q

What is a Postsynaptic Cell?

A

– cell that receives the signal.

128
Q

What is a Postsynaptic Neuron?

A

– carries the nerve impulse away from the synapse.

129
Q

What is an effector cell?

A

Responds to the impulse at the synapse.

130
Q

What are the 3 types of synapses between neurons?

A

Axodendritic
Axosomatic
Axoaxonic

131
Q

What type of synapse is from axon to dendrite?

A

Axodendritic

132
Q

What type of synapse is from axon to cell body?

A

Axosomatic

133
Q

What type of synapse is from axon to axon?

A

Axoaxonic

134
Q

At an __________synapse, action potentials conduct directly between the plasma membranes of adjacent neurons through structures called gap junctions.

A

Electrical

135
Q

Electrical synapses have two main advantages?

A
  1. Faster communication
  2. Synchronization
136
Q

In the electrical synapses, a__________ contains tubular connexions, which are tunnels that connect the cytosol of two cells. Action potentials spread from cell to cell.

A

Gap junction

137
Q

What are connexions?

A

Tunnels connect the cytosol of two cells. Action potentials spread from cell to cell.

138
Q

What are chemical synapses?

A

the presynaptic and postsynaptic neurons do not touch, and are separated by synaptic cleft

139
Q

True or false
Nerve impulses can conduct across the synaptic cleft.

A

False

140
Q

What is the synaptic cleft filled with?

A

interstitial fluid

141
Q

__________ diffuses through the fluid and binds to receptors of the postsynaptic neuron.

A

Neurotransmitter

142
Q

What is Postsynaptic Potential?

A

– Converted from a chemical signal by the postsynaptic neuron.

143
Q

Presynaptic neuron converts _______________signals (nerve impulse) into _________ signals (neurotransmitter).

A

Electrical
Chemical

144
Q

The postsynaptic neuron receives the chemical signal and in turn produces a postsynaptic potential into what type of potential

A

Graded

145
Q

Why do chemical synapses relay signals more slowly than electrical synapses?

A

Snaptic delay

146
Q

What is an excitatory postsynaptic potential (EPSP)?

A

Depolarizing postsynaptic potential.

147
Q

What is an Inhibitory Postsynaptic Potential (IPSP)?

A

Hyperpolarizing postsynaptic potential.

148
Q

A neurotransmitter that causes ___________ of the postsynaptic membrane is excitatory because it is closer to the threshold.

A

Depolarization

149
Q

The neurotransmitter that causes ________is inhibitory because it is further from the threshold.

A

hyperpolarization

150
Q

An ionotropic receptor is a type of neurotransmitter receptor that contains both a _________ and an ________

A

Binding site and an ion channel

151
Q

An ionotropic receptor is a type of__________channel

A

ligand-gated

152
Q

In an isotropic receptor, what causes the ligand-gated channel to open?

A

Neurotransmitters

153
Q

A metabotropic receptor is a type of neurotransmitter receptor that contains a neurotransmitter binding site but lacks________

A

Ion Channels

154
Q

A metabotropic receptor is coupled to a separate ion channel by a type of membrane protein called a ______

A

G protein

155
Q

What are the 3 ways a neurotransmitter is removed?

A
  1. Diffusion
  2. Enzymatic Degradation
  3. Uptake by cells
156
Q

What is Spatial Summation?

A

Summation of postsynaptic potentials due to stimuli occurring at different locations of the membrane at the same time.

157
Q

What is Temporal Summation?

A

Summation of postsynaptic potentials due to stimuli occurring at the same location of the membrane at different times.

158
Q

All the excitatory and inhibitory effects at any given time determine the effect on the postsynaptic neuron, which may respond in the following 3 ways

A

EPSP
Nerve Impulse(s)
IPSP

159
Q

If the total excitatory effects are greater than the total inhibitory effects but less than the threshold level of stimulation, the result is an _________ that does not reach threshold

A

EPSP

160
Q

If the total excitatory effects are greater than the total inhibitory effects and the threshold is reached, one or more ________ will be triggered.

A

Nerve impulses

161
Q

If the total inhibitory effects are greater than the excitatory effects, the membrane becomes ___________

A

hyperpolarizes (IPSP)

162
Q

What are Neurosecretory Cells

A

– Are neurotransmitters that secrete hormones.

163
Q

The small-molecule neurotransmitters include? 6 of them,

A

Acetylcholine, amino acids, biogenic amines, ATP and other purines, nitric oxide, and carbon monoxide.

164
Q

Is Acetylcholine an excitatory or inhibitory neurotransmitter?

A

Both
Excitatory neurotransmitter
&
Inhibitory neurotransmitter

165
Q

When is Acetylcholine an excitatory neurotransmitter?

A

binding of ACh to ionotropic receptors open cation
channels.

166
Q

When is Acetylcholine an inhibitory neurotransmitter?

A

binding to metabotropic receptors coupled to G Proteins
that open K+ channels.

167
Q

What are the 2 types of amino acids neurotransmitters?

A

Gamma-aminobutyric acid (GABA)
Glutamate

168
Q

Are the amino acids neurotransmitter GABA excitatory or inhibitory?

A

Inhibitory neurotransmitters.

169
Q

Are the amino acids neurotransmitter Glutamate excitatory or inhibitory?

A

Excitatory effects.

170
Q

What are the 4 types of biogenic amines?

A

Norepinephrine (NE) and Epinephrine
Dopamine (DA)
Catecholamines
Serotonin (5-HT)

171
Q

What are biogenic Amines?

A
  • Bind to metabotropic receptors causing either excitation or inhibition.
172
Q

What are Neuropeptides?

A

Found in CNS and PNS; bind to metabotropic receptors and have excitatory and inhibitory effects.

173
Q

What are Enkephalins?

A

Inhibit pain impulses by suppressing the release of substance P.

174
Q

What are Endorphins?

A

Inhibit pain by blocking the release of substance P.

175
Q

What is a Simple Series Circuit Type of Neural Circuit?

A

Presynaptic Neuron stimulates a single postsynaptic neuron.

176
Q

What is a Diverging Circuit Type of Neural Circuit?

A

Nerve impulses from a single presynaptic neuron causes stimulation of increasing numbers of cells along the circuit.

177
Q

What is a Converging Circuit Type of Neural Circuit?

A

Postsynaptic neuron receives nerve impulses from several different sources.

178
Q

What is a Reverberating Circuit Type of Neural Circuit?

A

-Incoming impulse stimulates the first neuron, then the second, third, and so on.
-Sends impulses back through the circuit again and again.

179
Q

What is a Parallel After-Discharge Circuit Type of Neural Circuit?

A

Single presynaptic cell stimulates group of neurons, each which synapses with a common postsynaptic cell.