Chapter 34: Neurons and Nervous Systems Flashcards
1
Q
neurons
A
nerve cells
2
Q
glia
A
glial cells
3
Q
cell body [of a neuron]
A
the nucleus and most organelles
where the typical cell ish stuff is found
4
Q
dendrites
A
likes tree branches
trees
bring info from other sources to the cell body, like the branches bring the products of photosynthesis to the trunk [but not really]
5
Q
excitable
A
neurons create and send electrical signals, which makes them excitable
6
Q
T or F: Neurons are excitable
A
true
7
Q
axon
A
a tail like projection that can be freakishly long, like almost as long as you are tall long.
telephone lines of the nervous systems
generate the action potentials, which will travel down the axon
8
Q
nerve
A
a bundle of axons that come from tons of neurons
9
Q
axon terminal
A
a bump like thing at the end of the axon that is super duper close to the target cell, forming a synapse
10
Q
synapse
A
tiny gap across which two neurons communicate, either electrically or chemically [neurotransmitters]
11
Q
presynaptic neuron
A
neuron that sends the signal
12
Q
postsynaptic neuron
A
neuron that receives the signal
13
Q
Astrocytes
A
Glia that surround the smallest, most permeable blood vessels that help prevent toxic chemicals from entering
14
Q
Neuroplasticity
A
Synapse modification
Glia play a role in that
15
Q
Glia
A
Don’t generate action potentials
Can release neurotransmitters
Support developing neurons during embryonic development
Maintain extra cellular environment and provide energy substrates
Assist in neuronal repair
16
Q
Blood-brain barrier
A
Prevents toxic chemicals and ether soluble/large molecules from reaching the brain
17
Q
Microglia
A
Provide the brain with immune with defenses
Act as macrophages and mediators of immune responses
18
Q
Oligodendrocytes
A
Glia in brain and spinal cord
Their membranes insulate axons
19
Q
Schwann cells
A
A type of glia
Insulate axons outside the brain and spinal cord with their membranes
20
Q
Myelin
A
A lipid rich no conductive sheath formed by the multilayered wrap of glial membranes
21
Q
White matter
A
Parts of the nervous system consisting of misty myelinated axons
22
Q
Gray matter
A
Areas of the nervous system that are rich in cell bodies
23
Q
Multiple sclerosis
A
Demyelinating disease
Autoimmune disease in which antibodies attack proteins in the myelin
24
Q
Neural networks
A
Information processing systems that neurons are organized into
25
Afferent neurons
Carry sensory info to nervous system
26
Sensory cells
Convert sensory stimuli into action potentials
27
Efferent neurons
Carry command to physiological and behavioral effectors like muscles and glands
28
Motor neurons
Type of effector neuron that carry commands to muscles
29
Interneurons
Integrate and store information and communicate between afferent and efferent
30
Ganglia
Clusters of neurons
31
Membrane potential
The difference in electrical potential across plasma membranes
32
Action potentials
Nerve impulses
large, sudden, and transient changes in membrane potential that travel alone axons and prompt the release of chemical signals at the axon terminals
33
Voltage
a measure of the difference in electrical charge between two points
potential energy
opposite charges will move together if given a chance
34
Is this an example of voltage difference?
Negative and positive poles of a battery are connected by a wire and an electric current flows through them [because of the possible voltage difference]
Yes
35
Membrane potential
a voltage across the cell membrane, caused by differing concentrations of ions on the outside and inside of the cell
36
Resting Potential
the membrane potential in an inactive neuron
37
What is the typical resting potential in a cell?
between -60 and -70 millivolts
38
True or false: The inside of the cell is electrically negative compared with the outside
True
39
True or False: Action Potential causes the inside of the cell to become more positive
True
40
sodium-potassium pump
aka sodium-potassium ATPase
| Sends Na+ out of the cell because it has no need for excessive amounts of positivity and brings in smaller amounts of K+
41
True or False: K+ and Na+ are the predominant ions in the extracellular fluid
false: Na+ and Cl- are the predominant ions in the extracellular fluid, K+ is more prevalent inside of the cell
42
If Na+ could follow its concentration gradient, it would move __________ of the cell?
inside, K+ would leave
43
True or false: concentration gradients generate resting potential
true
44
True or false: concentration gradients can change resting potential
true
45
Would you notice a voltage difference between electrodes placed in two places outside of a resting neuron?
nope, the difference lies between outside and inside of the cell
46
What is the voltage difference between the outside and inside of neurons caused by?
leak currents
47
Leak currents
occur because there are open channels which embrace the spirit of heyyyy let's be inclusive and let everyone in/out you do you ion
48
K+ leakage
one of the leakiest
| K+ diffuses outside of the membrane until the negative charge of the cell pulls it back
49
Electrochemical gradient
combination of the concentration gradient of the ion and the overall electric gradient of the cell
50
Equilibrium potential
of ions
no net movement
ex. K+ with an electrochemical gradient of 0 in a neuron
51
Voltage-gated channels
open or close in response to local changes in voltage across membrane
52
Chemically gated channels
open or close in response to certain molecules
53
Mechanically gated channels
open or close based on the mechanical force applied to the cell membrane
54
depolarized
ex. when neuron becomes more positive due to the influx of sodium ions
55
hyperpoalrized
neuron becomes more negative due to the influx of potassium ions
56
graded membrane potentials
small, local changes in membrane potential that vary in magnitude
integrate inputs in a cell
look at sum of all of the depolarizing and hyper polarizing
spreads quickly but decays as it spreads like water through leaky hose
57
True or False: graded membrane potentials can carry a signal all the way down an axon
false, only action potentials do this
58
axon hillock
region of the cell body at the base of the axon
high concentration of Na+ gates
must let in enough Na+ in order to reach the threshold for the neuron to fire
59
refractory period
Na+ gated channels can not open again
| prevent signal form going backwards
60
all-or-nothing
DESCRIBES ACTION POTENTIALS oops caps lock
| either firing or isn't, no different rates
61
Why all-or-nothing?
positive feedback loop for Na+ gated channels
62
`self-regenerating
spread by local current to neighbors
63
describe axon potentials
all-or-nothing self-regenerating
64
True or False: Action potentials travel along all axons at the same speed
False
65
True or False: Action potentials fire faster with long diameter
true
66
myelination
glia wrap themselves around axons
67
nodes of Ranvier
unmyelinated gaps
68
saltatory conduction
action potentials jump from node to node
69
chemical synapse
most common type
| neurotransmitters are released from presynaptic cell and bind to receptors in postsynaptic cell, causing a change
70
Synaptic Cleft
space between presynaptic and postsynaptic cell
71
Electrical Synapses
join cytoplasms of pre and post synaptic cells through GAP Junctions
72
Gap Junctions
made up of proteins that create channels
ions flow through these allowing a passive spread of action potential
Pro: fast transmission
Con: don't allow for complicated integration from many different sources
73
connexins
proteins that make up gap junctions
74
neuromuscular junctions
synapses between motor neurons and skeletal muscles
75
bouton
end of axon terminal that contains vesicles full of neurotransmitters
76
ACh
neurotransmitter used by vertebrate neuromuscular synapses
77
Which voltage gate opens first at neuromuscular junctions?
Ca2+, the ion flows into the axon terminal where it causes ACh vesicles to fuse with the presynaptic membrane
78
motor end plate
depression formed by the postsynaptic membrane of a neuromuscular junction, when ACh binds to this, Na+ and K+ flow through, making inside more positive and causing depolarization
79
excitatory
causes depolarization
80
inhibitory
causes hyperpolarization
81
Summation
integrating the influences of many different inputs
82
Spatial Summation
Adds up the simultaneous influences of synapses at different sites on a cell
83
Temporal Summation
adds up potentials generated at the same site in a rapid sequence
84
How can neurotransmitter action be terminated?
Enzymes destroy it
diffuse away
get taken up by cell membranes
85
True or false: Every neurotransmitter can have multiple receptor sites
True
| ex. ACh has nicotinic receptors and muscarinic receptors
86
Muscarinic receptors
ACh, tend to be inhibitory
87
Nicotinic receptors
ACh, tend to be excitatory
88
Where do neurotransmitters come from?
cell body
89
Ionotropic Receptors
Ion channels
| quick, short-lived responses
90
Metabotropic Receptors
Not ion channels, cause signaling cascades
| slower and longer lived
91
Central Nervous System (CNS)
brain and spinal cord
92
Peripheral Nervous System (PNS)
neurons not in brain and spinal cord
93
Autonomic Nervous System (ANS)
output of CNS that control involuntary function
| ex. heartbeat, sweat
94
Sympathetic Division
Part of ANS
| fight or flight
95
Parasympathetic Division
part of ANS
rest and digest
parachute
96
Preganglionic Neuron
cell body in CNS that begins autonomic pathways
97
Nonadrenergic Neurons
release norepinephrine
| sympathetic
98
Cholinergic Neurons
release acetylcholine
| Parasympathetic
99
Pacemaker
part of heart that generates beat
receives input from both para and symp
they produce opp effects
100
Gray Matter
Rich in cell bodies
101
White Matter
rich in myelinated axons
102
spinal reflexes
information doesn't go to the brain, spinal cord just gives a simple reaction
103
monosynaptic reflexes
involve two neurons and one synapse
ex. knee jerk reaction
simplest of spinal reflexes
104
Antagonistic pairs of muscles
Flexors and extensors
105
Brainstem
pons, medulla, and midbrain
106
reticular system
network of brainstem neurons
107
diencephalon
central region of the brain
| thalamus and hypothalamus--- maintains homeostasis
108
telencephalon
Surrounds diencephalon
| limbic system
109
limbic system
instinctive reactions
| pleasure, pain, fear, emotion, memory
110
Amygdala
Emotion
| fear and fear memories
111
Hippocampus
memory
112
Cerebrum
outer part of telencephalon
113
Muscle spindles
Modified muscle fibers in the quadriceps that form stretch receptors that are inner cared by the neuron
114
Cerebrum
Dominant part of mammalian brain
| Two hemispheres
115
Left and right cerebral hemispheres
Make up cerebrum
| Cover outer parts of brain with the exception of cerebellum
116
Cerebral cortex
Outermost layer of cerebral cortex
117
Convolutions
Ridges that the cerebral cortex is folded into to maximize surface area
118
Association cortex
Areas of the cerebral cortex that are involved in higher order information processing
Hard to define specific function because responsible for integration of information from many different senses and memory
119
Temporal lobe
Processes auditory info
Also visual processing
Association areas recognize, identify, and name objects
120
Agnosias
Disorders caused by damage to the temporal love
| Aware of object but can't identify
121
Frontal lobe
Association areas involved with feeling and planning contribute to personality
122
Primary motor cortex
In frontal lobe
| Neurons in this region control muscles in specific parts of the body
123
Parietal lobe
Association area attends to complex stimuli
| Visual info to 3D
124
Primary somatosensory cortex
In parietal lobe
| Receives touch and pressure information
125
Occipital lobe
Receives and processes visual info
Association areas make sense of visual world and translate visuals into language
Ex. Woman with damage can't see motion, just still images
126
Lateralization
Occurs mainly in one half of the brain
| Ex. Language
127
T or F: language abilities are localized in the left hemisphere
True
128
Aphasia
Deficit in ability to use or understand words
| Often from damage to left hemisphere
129
Broca's area
In frontal lobe
A language area
Essential for PRODUCTION of language
Patients with damage to this area can still understand speech
130
Wernicke's area
Located in temporal lobe
A language area
Essential to UNDERSTANDING language
Patients with damage to this area can produce fluent sounding gibberish
131
Learning
Modification of behavior by experience
132
Memory
Ability of nervous system to retain what it has learned and experienced
133
Long-term potentiation (LTP)
High frequency electrical stimulation is neuronal circuits makes them
More sensitive to later stimulation
134
Associative learning
Two unrelated stimuli linked to same response
135
Conditioned reflex
Example of associative learning
Pavlov
Ex. Dog salivation experiment
136
Observational learning
More complex
Watch another person exhibit behavior
Form and store a memory of that
Copy/use info
137
Declarative memory
I know that....
Memory of events/facts:people
Conscious recall and description
138
Procedural memory
Perform a task
| Ride a bike
139
Immediate memory
RIGHT NOW almost photographic but lasts about 2 seconds
140
Short-term memory
Not as much info as immediate, but longer lasting
141
Long-term memory
Lasts the longest amount of time
142
True or False: sleepwalking occurs during REM sleep
False
143
true or false: the body is paralyzed during REM sleep
True
144
REM sleep
Stands for rapid eye movement
Body is paralyzed
Vivid dreams
Brain activity most similar to an awake brain
145
Non-REM sleep
Stages 1-4 of sleep
| Majority of sleep is non REM (in adults)
146
Insular cortex (insula)
Part of forebrain
| Integrates info from all over the body to create a sensation of how the body feels
147
Muscle spindles
Modified muscle fibers in the quadriceps that form stretch receptors that are inner cared by the neuron
148
Cerebrum
Dominant part of mammalian brain
| Two hemispheres
149
Left and right cerebral hemispheres
Make up cerebrum
| Cover outer parts of brain with the exception of cerebellum
150
Cerebral cortex
Outermost layer of cerebral cortex
151
Convolutions
Ridges that the cerebral cortex is folded into to maximize surface area
152
Association cortex
Areas of the cerebral cortex that are involved in higher order information processing
Hard to define specific function because responsible for integration of information from many different senses and memory
153
Temporal lobe
Processes auditory info
Also visual processing
Association areas recognize, identify, and name objects
154
Agnosias
Disorders caused by damage to the temporal love
| Aware of object but can't identify
155
Frontal lobe
Association areas involved with feeling and planning contribute to personality
156
Primary motor cortex
In frontal lobe
| Neurons in this region control muscles in specific parts of the body
157
Parietal lobe
Association area attends to complex stimuli
| Visual info to 3D
158
Primary somatosensory cortex
In parietal lobe
| Receives touch and pressure information
159
Occipital lobe
Receives and processes visual info
Association areas make sense of visual world and translate visuals into language
Ex. Woman with damage can't see motion, just still images
160
Lateralization
Occurs mainly in one half of the brain
| Ex. Language
161
T or F: language abilities are localized in the left hemisphere
True
162
Aphasia
Deficit in ability to use or understand words
| Often from damage to left hemisphere
163
Broca's area
In frontal lobe
A language area
Essential for PRODUCTION of language
Patients with damage to this area can still understand speech
164
Wernicke's area
Located in temporal lobe
A language area
Essential to UNDERSTANDING language
Patients with damage to this area can produce fluent sounding gibberish
165
Learning
Modification of behavior by experience
166
Memory
Ability of nervous system to retain what it has learned and experienced
167
Long-term potentiation (LTP)
High frequency electrical stimulation is neuronal circuits makes them
More sensitive to later stimulation
168
Associative learning
Two unrelated stimuli linked to same response
169
Conditioned reflex
Example of associative learning
Pavlov
Ex. Dog salivation experiment
170
Observational learning
More complex
Watch another person exhibit behavior
Form and store a memory of that
Copy/use info
171
Declarative memory
I know that....
Memory of events/facts:people
Conscious recall and description
172
Procedural memory
Perform a task
| Ride a bike
173
Immediate memory
RIGHT NOW almost photographic but lasts about 2 seconds
174
Short-term memory
Not as much info as immediate, but longer lasting
175
Long-term memory
Lasts the longest amount of time
176
True or False: sleepwalking occurs during REM sleep
False
177
true or false: the body is paralyzed during REM sleep
True
178
REM sleep
Stands for rapid eye movement
Body is paralyzed
Vivid dreams
Brain activity most similar to an awake brain
179
Non-REM sleep
Stages 1-4 of sleep
| Majority of sleep is non REM (in adults)
180
Insular cortex (insula)
Part of forebrain
| Integrates info from all over the body to create a sensation of how the body feels
