Chapter 1 Flashcards
(214 cards)
1
Q
What is the function of the brain?
A
Nerve center; processes info
2
Q
How many neurons does the brain contain?
A
Billions
3
Q
Can the brain perform multiple tasks at once?
A
Yes
4
Q
What is the largest part of the human brain?
A
Cerebrum
5
Q
What connects the two hemispheres of the brain?
A
Corpus callosum
6
Q
How many hemispheres is the cerebrum divided into?
A
Two
7
Q
What is the surface layer of the cerebrum called?
A
Cerebral cortex
8
Q
What do the folds of the cerebral cortex do?
A
Increase area for neurons
9
Q
How do neuroscientists identify regions of each hemisphere?
A
Separate lobes
10
Q
Where are the frontal lobes located?
A
Front of the brain, above eyes
11
Q
What functions do the frontal lobes coordinate?
A
Movement, speech, memory
12
Q
Where are the parietal lobes located?
A
Top of the brain, behind frontal lobes
13
Q
What do the occipital lobes process?
A
Visual information
14
Q
What are the occipital lobes responsible for recognizing?
A
Colors and shapes
15
Q
Where are the temporal lobes located?
A
Sides of the brain
16
Q
What type of information do temporal lobes interpret?
A
Auditory information
17
Q
What is the function of the hippocampus?
A
Encodes new memories
18
Q
What does the amygdala integrate?
A
Memory and emotion
19
Q
What system do the hippocampus and amygdala belong to?
A
Limbic system
20
Q
What role does the thalamus play?
A
Integrates sensory information
21
Q
What does the hypothalamus send to the body?
A
Hormonal signals
22
Q
What structures make up the forebrain?
A
Cerebral cortex and others
23
Q
Where does the midbrain sit?
A
Beneath the thalamus
24
Q
What functions do neurons in the midbrain coordinate?
A
Eye movements
25
What is an example of a reflex triggered by the midbrain?
Startled jump
26
What does the midbrain help manage?
Fine motor control
27
What collection of structures helps regulate complex body movements?
Basal ganglia
28
What part of the brain is involved in glucose regulation and sleep?
Hindbrain
29
Which part of the brain is the second-largest by volume?
Cerebellum
30
Where is the cerebellum located?
Under occipital lobe
31
What contains over half the brain’s neurons?
Cerebellum
32
What are the functions of the cerebellum?
Coordinates movements, motor skills
33
What might indicate cerebellar damage?
Jerky gait, poor finger touch
34
What part of the brain below the cerebellum influences breathing and posture?
Pons
35
What does the medulla control?
Basic functions
36
What makes up the brainstem?
Midbrain, pons, medulla
37
What is the frontal lobe responsible for?
Attention, planning, decision-making
38
What is the function of the temporal lobe?
Language, memory, emotion
39
What does the parietal lobe integrate?
Information from senses
40
What is the responsibility of the occipital lobe?
Vision
41
What did the brain begin as?
Simple tube
42
What regions are present in early vertebrates' brains?
Forebrain, midbrain, hindbrain
43
What expanded in the forebrain?
Olfactory bulbs
44
What evolved with the development of eyes?
Light-sensing regions
45
What part of the brain controls escape movements in fish?
Cerebellum
46
What functions are expanded in vertebrates for processing?
Visual, auditory
47
What behaviors do the expanded regions trigger?
Escape, feeding, mating
48
What formed the cerebral hemispheres?
New types of neurons
49
What expanded in early mammals?
Cortical tissues
50
How does information move in the brain?
Chains of neurons
51
How do neural networks route signals?
Along a linear pathway
52
What cells in the retina trigger electrical signals?
Photoreceptors
53
Where do signals travel after the optic nerve?
Optic tract to thalamus
54
What does the primary visual cortex process?
Shape, color, movement
55
Where is the primary visual cortex located?
Occipital lobe
56
What do neurons in the primary visual cortex detect?
Edges of objects
57
What representation is created by the integration of signals from each eye?
Three-dimensional
58
What happens to the image as signals are sent down processing streams?
Further refined
59
What do neurons in the temporal lobe recognize and identify?
Objects
60
What do neurons in the parietal lobe detect?
Spatial location of objects
61
What do new technologies allow us to see?
Brain regions activated during different functions
62
What creates brain waves?
Network activity
63
What is an example of a thalamocortical loop?
Visual cortex sending signals back to the thalamus to integrate with other sensory information
64
What produces rhythmic electrical patterns detected by EEG?
Neuronal signals
65
What are the rhythmic electrical patterns called?
Brain waves
66
How many distinct types of brain waves are there?
Four
67
What are alpha waves?
8-13 Hz, relaxed brain
68
Where do alpha waves originate?
Parietal and occipital lobes
69
What are beta waves?
14-30 Hz, active brain
70
Where do beta waves originate?
Frontal and parietal regions
71
What frequency range do theta waves have?
4 to 7 Hz
72
What frequency is typical for delta waves?
< 3.5 Hz
73
Which waves occur during deep sleep?
Delta waves
74
What is the amplitude range for alpha waves?
20–200 μV
75
What is the amplitude range for delta waves?
20–200 μV
76
What is the amplitude range for theta waves?
5-10 μV
77
What is the amplitude range for beta waves?
5-10 μV
78
What are neural networks?
Organized and integrated information passages in the brain and spinal cord.
79
What are spinal tracts?
Chains of neurons passing signals through the brainstem and spinal cord.
80
What is the purpose of spinal tracts?
To pass signals from sensory receptors to the thalamus and cortex, and from brain regions to muscles.
81
What do basal ganglia do?
Feedback loop for movement
82
What influences the timing and strength of motor signals?
Loops from brainstem and cerebellum
83
What enables environmental and emotional context to influence body movements?
Tracts from cerebral cortex
84
What do networks looping the hippocampus into sensory cortex pathways do?
Analyze environmental signals
85
What do networks linking the hippocampus to the thalamus and hypothalamus influence?
Memory impacts behavior
86
What are reflex loops?
Action before thoughts
87
Where are reflex actions controlled?
Spinal cord or subcortical regions
88
What do brain regions analyze?
Specialized subsets of information
89
What do local neural circuits do?
Turn signals into output patterns
90
What is a characteristic of the cerebral cortex?
Packed with neural circuits
91
How are neurons organized within the cerebral cortex?
Stack of distinct layers
92
How are circuits arranged within the cerebral cortex?
Columns
93
How are signals processed within a column of neurons?
Travel down a chain from one neuron to the next
94
What does each column in the cortex do?
Specific processing task
95
How can a column's output be influenced?
Nearby circuits activity
96
What behavior do neurons exhibit?
Like microprocessors
97
What affects a neuron's response?
Strength of signals
98
How are neurons organized in the cortex?
Into distinct layers
99
What percentage of neurons are excitatory?
About 80 percent
100
What is the most common type of excitatory neuron?
Pyramidal cell
101
What shape is the cell body of a pyramidal cell?
Cone-shaped
102
What type of axon sends a signal to multiple destinations?
Multi-branched axon
103
What percentage of neurons in the brain are inhibitory?
20 percent
104
What do inhibitory neurons do?
Suppress neighboring neurons
105
What type of neurons pass signals forward in a circuit?
Excitatory neurons
106
Where do inhibitory neurons typically loop their responses?
Earlier segments
107
What is important in learning and tuning signals in the brain?
Interplay of signals
108
What could cause seizure disorders like epilepsy?
Imbalances in neuron activity
109
What is a feed-forward inhibitory circuit?
Inhibitory interneurons connect circuits.
110
What does a feed-forward inhibitory circuit do?
Reduces activity in adjacent columns.
111
What characterizes feedback inhibition?
Signals inhibit preceding layers.
112
What is the functional unit of neural circuits?
Neuron
113
What are the main parts of a neuron?
Cell body, dendrites, axon
114
What is the cell body also called?
Soma
115
What does the cell body contain?
Nucleus, cytoplasm
116
What are dendrites responsible for?
Collecting incoming signals
117
What do electrical signals travel down?
Axon
118
What are axon terminals?
End points of axon
119
What is passed across a synapse?
Signal
120
What types of cells are neurons associated with?
Glia
121
How many main types of glial cells are in the CNS?
Four
122
What are the types of glial cells in the CNS?
Astrocytes, microglia, ependymal cells, oligodendrocytes
123
What was the believed ratio of glia to neurons before recent investigations?
0.41736111111111107
124
What is the suggested glia-neuron ratio in some brain regions?
0.04236111111111107
125
Do glia-neuron ratios vary across brain regions?
Yes
126
¿Qué regulan los astrocitos?
Concentraciones de iones
127
¿Qué nutrientes proporcionan los astrocitos?
Nutrientes a las neuronas
128
¿Qué papel juegan las microglías?
Células inmunitarias
129
¿Cómo protegen las microglías el cerebro?
Fagocitos
130
¿Qué regulan las microglías?
Conexiones neuronales
131
What do ependymal cells do?
Make cerebrospinal fluid
132
How do oligodendrocytes improve neuron function?
Wrap axons in myelin
133
What allows ions to cross a neuron's cell membrane?
Ion channels
134
What do ion channels do?
Act like gates for ions
135
What changes when ions enter or leave the cell?
Voltage difference
136
What is the resting membrane potential of a neuron?
-70 mV
137
What are the two types of signals that affect membrane potential?
Depolarized and hyperpolarized
138
What triggers an action potential?
Threshold voltage
139
What are signals passed through?
Synapses
140
What does a synapse include?
Axon end, dendrite, synaptic cleft
141
When was the separation between neurons verified?
1950s
142
What crosses the synapse?
Neurotransmitters
143
What triggers ion channels to open?
Voltage change
144
What ions flow into the cell?
Calcium ions
145
What happens when calcium ions bind to synaptic vesicles?
Vesicles fuse with cell membrane
146
What do synaptic vesicles release into the synaptic cleft?
Neurotransmitter molecules
147
What is cycled back into the soma?
Pieces of axon terminal membrane
148
What substances can act as neurotransmitters?
Amino acids, gases, chemicals, peptides
149
What is the basic building block of the nervous system?
Neuron
150
What do dendrites do?
Receive signals
151
What is released by axon terminals?
Neurotransmitters
152
What is the function of the axon?
Send signals
153
What structures are contained in the cell body?
Nucleus
154
What are the sites called where dendrites receive information?
Synapses
155
What forms complex circuits in the brain?
Synapses on dendrites
156
What colors label synapses in the mouse neuron?
Yellow and red
157
What is the postsynaptic density?
Dense receptor area
158
How do neurotransmitters interact with receptors?
Key fits a lock
159
What happens to neurotransmitters after release?
Drift across synaptic cleft
160
What is located in high concentration at the postsynaptic density?
Neurotransmitter receptors
161
What happens when neurotransmitters bind to receptors?
Open ion channels
162
What do astrocytes do at the synapse?
Mop up excess neurotransmitters
163
What is an ionotropic receptor?
Binds neurotransmitter directly to ion channel
164
What happens when a neurotransmitter attaches to the ion channel?
Channel widens, ions move
165
How are metabotropic receptors different from ion channels?
Different proteins, distant
166
What triggers the cascade in metabotropic receptors?
Neurotransmitter binding
167
What is the brain's most common excitatory neurotransmitter?
Glutamate
168
What is the brain's most common inhibitory neurotransmitter?
GABA
169
What do excitatory neurons produce?
Depolarizing neurotransmitters
170
What do inhibitory neurons produce?
Hyperpolarizing neurotransmitters
171
What is a key characteristic of glutamate?
Half the excitatory synapses
172
What are the most important ionotropic receptors?
AMPA and NMDA receptors
173
What is the action of AMPA receptors?
Fast and brief
174
How do NMDA receptors activate?
More slowly
175
What is the role of interactions between AMPA and NMDA receptors?
Learning and memory
176
What is the most important inhibitory neurotransmitter?
GABA
177
What groups of receptors does GABA bind to?
Ionotropic and metabotropic
178
What do ionotropic GABA receptors let enter the cell?
Negatively charged chloride ions
179
What do metabotropic GABA receptors release?
Potassium ions
180
What is the effect of ion movement in GABA receptors?
Inhibits neuron firing
181
What role do hormones play in the brain?
Send specific cues
182
What are endocannabinoids?
Neuromodulators that suppress neurotransmitter release
183
What do prostaglandins increase?
Pain sensitivity
184
What triggers a series of chemical reactions inside the cell?
Hormones and neuromodulators
185
What initiates the signal transduction pathway?
Molecule binding to receptor
186
What happens when a molecule binds to a surface receptor?
Changes receptor shape
187
What does the signal transduction pathway modify?
Neuronal function
188
How can steroid hormones like estradiol act inside a neuron?
Diffuse through cell membrane
189
What determines whether a neuron's signal is excitatory or inhibitory?
Type of neurotransmitter
190
What determines a cell's sensitivity to specific neurotransmitters?
Neurotransmitter receptors
191
What can influence neuronal behavior?
Neuromodulators
192
What are examples of neuromodulators that influence neuronal behavior?
Hormones (vasopressin, estradiol, cortisol)
193
Where are neuromodulator receptors located?
Cell membranes
194
What is gene expression?
Directs cellular activities
195
What do differences among neurons result from?
Differences in gene expression
196
How do cells build proteins?
From a subset of genes
197
What is an analogy for gene expression differences?
Building with Lego blocks
198
What do genes need to be accessible?
Open, unfolded chromatin
199
What associates with unexpressed genes?
Tightly packed regions
200
What can shut down genes on DNA?
Tightening chromatin
201
What activates genes on DNA?
Spreading chromatin
202
What makes neurons flexible in altering their gene expression?
Reversible changes
203
Where can genetic differences between individuals be found?
Genes that affect neuron structure and function
204
What do alleles reflect?
Nucleotide sequence differences
205
What can alleles produce?
Variants that affect protein function
206
What does an allele code for?
Version of an enzyme
207
What condition is caused by Tay-Sachs disease?
Mutations in enzyme gene
208
What enzyme is affected in Tay-Sachs disease?
Beta-hexosaminidase A
209
What accumulates in neurons due to Tay-Sachs?
Specific fats
210
What is the outcome of fat accumulation in Tay-Sachs?
Toxicity
211
What affects brain function?
Small changes in genetic sequence
212
What is now possible for understanding brain disorders?
Sequence a person's entire genome
213
What acts as neurotransmitters?
Many different molecules
214
What is the receptor's role?
Fits neurotransmitters like a key fits a lock
