Revision (Level 4) Flashcards
1
Q
What is neuroscience?
A
The field of science that studies the structure & function of the nervous system.
2
Q
Which 2 subjects merge into 1 to form neuroscience?
A
Biology & psychology
3
Q
At which levels can human behaviour be studied?
A
At the behavioural, organ, neural system, circuit, cellular, synaptic, and molecular levels.
4
Q
What are examples of cells that can be used to study human behaviour?
A
Neurones and glia
5
Q
How can cells contribute to our understanding of human behaviour?
A
Some of them are the building blocks of the CNS & others have specialised functions.
6
Q
What is an example of a circuit that can be used to study human behaviour?
A
The myotatic spinal reflex (aka the ‘knee jerk’ reaction)
7
Q
How can circuits contribute to our understanding of human behaviour?
A
Some of them can enable specific cell-to-cell communication
8
Q
What are examples of systems that can be used to study human behaviour?
A
The motor, sensory & associational systems.
9
Q
How can systems contribute to our understanding of human behaviour?
A
Some of them can tell us about the general state of an organism, as well as enable perception, movement & ‘higher order’ functioning.
10
Q
What does our nervous system consist of?
A
Neurones (cells responsible for transmitting & receiving electrochemical information)
11
Q
What do dendrites receive from other cells?
A
Messages
12
Q
What do axons pass from the cell body to other neurones, muscles, or glands?
A
Messages
13
Q
What is a neural impulse?
A
An action potential (an electrical signal travelling down the axon)
14
Q
What is a cell’s life-support centre?
A
The cell body
15
Q
What does myelin sheath cover?
A
The axons of some neurones
16
Q
What does myelin sheath help speed up?
A
Neural impulses
17
Q
What do the terminal branches of neurones form junctions with?
A
Other cells
18
Q
What types of neurones are there?
A
Sensory, motor & interneurones
19
Q
Which neurones carry incoming information from sense receptors to the CNS?
A
Sensory neurones
20
Q
Which neurones carry outgoing information from the CNS to muscles & glands?
A
Motor neurones
21
Q
Which neurones connect sensory & motor neurones?
A
Interneurones
22
Q
What form circuits?
A
Interconnected neurones
23
Q
Are circuits made up of interconnected neurones complex or simple?
A
Complex
24
Q
How do circuits made up of interconnected neurones modify?
A
With growth and experience
25
What do complex neural networks look like?
They look like many cell bodies connected by axons, sending information to each other.
26
In the withdrawal reflex, what detect a painful stimulus?
Dendrites of the sensory neurone
27
In the withdrawal reflex, what does pain sensation travel down?
The axon of a sensory neurone.
28
What can happen to muscles in the withdrawal reflex?
They cause withdrawal from the source of the pain.
29
With what type of neurone does a sensory neurone synapse in the withdrawal reflex?
An interneurone in the spinal cord
30
In the withdrawal reflex, what type of neurone excites a motor neurone, causing muscular contraction?
An interneurone in the spinal cord
31
What causes the withdrawal of muscles from the source of pain in the withdrawal reflex?
A motor neurone in the spinal cord
32
What does the brain connect to?
The spinal cord
33
What type of neurones can inhibit motor neurones in the withdrawal reflex, preventing muscular contraction?
Interneurones from the brain
34
What extend from neurones in the brain through the spinal cord?
Axons of neurones
35
What does a cross-section of a spinal cord look like?
It looks like a butterfly shape inside of a lobed spherical structure.
36
What are the 2 parts of the nervous system?
The central & peripheral nervous system
37
What does the central nervous system consist of?
The brain & spinal cord
38
What are the 2 parts of the peripheral nervous system?
The autonomic & somatic nervous system
39
With what does the autonomic nervous system communicate?
Internal organs & glands
40
With what does the somatic nervous system communicate?
Sense organs & voluntary muscles
41
What are the 2 parts of the autonomic nervous system?
The sympathetic (arousing) & parasympathetic (calming) division
42
What are the 2 components of the somatic nervous system?
The sensory (afferent) & motor (efferent) nervous systems
43
What is the sensory nervous system responsible for?
Sensory input
44
What is the motor nervous system responsible for?
Motor input
45
In which part of the body is the central nervous system located?
In the upper & middle parts.
46
In which part of the body is the peripheral nervous system located?
In the upper, middle & lower parts of the body.
47
What can the naked eye distinguish?
Grey & white parts in the brain & spinal cord.
48
What is grey matter made up of?
The cell bodies of neurones.
49
What is white matter made up of?
The axons of neurones
50
Is the 'butterfly-shaped' part of the spinal cord made up of grey or white matter?
Grey matter
51
Is the 'shell-shaped' part of the spinal cord made up of grey or white matter?
White matter
52
What is the diameter of the spinal cord?
1 - 1.5 cm
53
What does the term 'medial' refer to?
Moving inward from the outer body area towards the spinal cord.
54
What does the term 'lateral' refer to?
Moving outward from the spinal cord towards the outer body area.
55
Towards where is the term 'dorsal' (superior/ posterior) referring?
Either the top of the brain or the back of the spine.
56
Towards where is the term 'anterior' (rostral) referring?
Either the front of the brain or the top of the spinal cord.
57
Towards where is the term 'posterior' (caudal) referring?
Either the back of the brain or the bottom of the spine.
58
Towards where is the term 'ventral' (inferior/ anterior) referring?
Either the bottom of the brain or the front of the spinal cord.
59
In which direction do the brain coordinates rotate as we move down the spinal cord?
Backwards
60
From a sideways (lateral) perspective, what is the largest visible sulcus in the brain?
The lateral sulcus
61
What part of the face & head would you cut to produce a horizontal plane?
Horizontally in between the eyes and nose.
62
What part of the face & head would you cut to produce a coronal (frontal) plane?
Vertically through each temple
63
What part of the face & head would you cut to produce a mid-sagittal (medial) plane?
Vertically through the middle of the face.
64
What are the 3 section planes?
The horizontal, coronal & sagittal planes.
65
What is the cervical spine?
The first 7 stacked vertebral bones of your spine
66
What is the forebrain?
The anterior part of the brain.
67
How could you describe what the medial view of the left hemisphere of the brain looks like?
It is the inside of one hemisphere of the brain and contains an unfinished loop-like structure and a (severed) tube at the bottom.
68
What does the thalamus serve as?
The brain's main relay station.
69
What does the thalamus look like?
It sits under the unfinished loop-like structure in the brain and consists of a small sphere inside of a sperm-shaped structure.
70
What is the main function of the pineal body?
To receive information about the state of the light-dark cycle from the environment & convey this information by the production & secretion of the hormone melatonin.
71
What does the pineal body look like?
A small, round appendage attached to the unfinished loop-like structure.
72
What is the main function of the cerebellum?
Maintaining balance & posture
73
What does the medulla do?
It manages the heart, circulation & breathing.
74
What does the pons do?
It handles unconscious processes such as the sleep-wake cycle & breathing.
75
What does the tectum do?
It receives visual information in a spatially-arranged retinotopic map.
76
What does the tegmentum do?
It relays inhibitory signals to the thalamus & basal nuclei preventing unwanted body movement.
77
What does the tectum look like?
2 little hills just behind the tegmentum.
78
What does the tegmentum look like?
A cube-like structure just in front of the tectum.
79
What does the hypothalamus do?
It produces hormones that control body temperature, heart rate & hunger.
80
What does the hypothalamus look like?
A cube-like space underneath the thalamus.
81
Which 2 structures make up the midbrain?
The tegmentum & the tectum.
82
What is the brain?
The command centre of the human body
83
How much does the brain weigh?
3 pounds
84
What is an example of what the brain can do?
Store memories
85
How many neurones does the brain contain?
Around 86 billion
86
What are neurones?
Specialised cells that can communicate with each other using chemical & electrical signals.
87
How do groups of neurones link together to form neural circuits?
Via long connections called axons
88
What are organised differently in discrete brain regions that carry out different tasks?
Neural circuits
89
What interconnect to coordinate actions like guiding motor skills using visual information?
Different regions of the brain
90
What are glia?
Support cells which provide & maintain the optimal environment for the growth & interaction of neurones.
91
During neurotransmission, when does an action potential (AP) occur?
If the depolarisation of a cell membrane exceeds a particular threshold.
92
Are APs sudden & brief or long-lasting during neurotransmission?
Sudden & brief
93
How long do APs last during neurotransmission?
0.5 - 2 ms
94
What do APs momentarily reverse during neurotransmission?
Cell membrane potential
95
What quickly repolarises before overshooting during neurotransmission?
Cell membrane potential
96
Is the magnitude of an AP fixed or flexible during neurotransmission?
It's fixed
97
What kind of response is an AP?
An all-or-nothing response
98
What governs the flux of Na+ & K+ ions into & out of cells during neurotransmission?
A complex cascade of opening & closing of voltage-gated ion channels.
99
In the process of an AP, do Na+ ion channels open before or after K+ channels?
Before
100
In the process of an AP, do Na+ ions flow into/ out of a cell?
Into the cell
101
In the process of an AP, do K+ ions flow into/ out of a cell?
Out of the cell
102
During which of the 5 stages of an AP are Na+ ion gates open during neurotransmission?
During stages 1 & 4
103
During which of the 5 stages of an AP are K+ ion gates open during neurotransmission?
During stages 2 & 4
104
During which of the 5 stages of an AP are K+ ion gates closed during neurotransmission?
During stage 5
105
During which of the 5 stages of an AP are Na+ ion gates closed during neurotransmission?
During stage 3
106
During which of the 5 stages of an AP is the inside of the cell more negative than the outside of the cell during neurotransmission?
During stages 1, 2, half of 4, and 5.
107
During which of the 5 stages of an AP is the inside of the cell more positive than the outside of the cell during neurotransmission?
During stage 3 & half of stage 4
108
During which of the 5 stages of an AP does Na+ enter a cell during neurotransmission?
During stages 1 & 5
109
During which of the 5 stages of an AP does K+ leave a cell during neurotransmission?
During stages 2 & 4
110
Which of the 5 stages of an AP is the refractory stage?
Stage 3
111
Which of the 5 stages of an AP is the reset stage?
Stage 5
112
Which of the 5 stages of an AP are the open stages?
Stages 1, 2 & 4
113
What is resting membrane potential?
-70 mV
114
Which channels become refractory in stage 3 of an AP during neurotransmission?
Na+ channels
115
What can no longer enter a cell in stage 3 of an AP during neurotransmission?
Na+
116
In an AP, what causes membrane potential to return to its resting level?
K+ leaving the cell
117
What diffuses away during stage 6 of an AP during neurotransmission?
Extra K+
118
What is the withdrawal reflex?
A neural circuit
119
What can be used to alter the potential of a membrane during neurotransmission?
An electrical stimulator
120
What can depolarise a membrane's potential during neurotransmission?
Positive current
121
Do weak changes in the potential of a membrane during neurotransmission affect it or does this not do much?
It doesn't do much
122
When is an action potential created?
When the potential of a membrane reaches the threshold of excitation.
123
What is an action potential?
A very rapid reversal of a membrane's potential
124
Which law applies to action potentials?
The all-or-none law
125
What does the all-or-none law claim?
That action potentials either fire or don't fire.
126
When is an action potential not affected by the size of a stimulus during neurotransmission?
When a membrane's potential is above a certain threshold.
127
When a membrane's potential is above a certain threshold during neurotransmission, how is stimulus intensity coded?
By the frequency of action potentials.
128
What do action potentials caused by a weak stimulus look like before & after the stimulus is present?
Vertical lines that occur infrequently along a main horizontal line.
129
What do action potentials caused by a weak stimulus look like while the stimulus is present?
Vertical lines that occur relatively frequently along a main horizontal line.
130
What do action potentials caused by a strong stimulus look like before & after the stimulus is present?
Vertical lines that occur infrequently along a main horizontal line.
131
What do action potentials caused by a strong stimulus look like while the stimulus is present?
Vertical lines that occur extremely frequently along a main horizontal line.
132
What can cause failed initiations of action potentials?
A stimulus
133
At what voltage is a membrane at its resting state?
-70 mV
134
What happens when a membrane's potential exceeds -55 mV during neurotransmission?
The membrane depolarises & an action potential begins to occur.
135
What exists at a membrane potential of -55 mV?
A threshold
136
What enter cells during membranal depolarisation?
Na+ ions
137
What happens when a membrane's potential reaches +40 mV during neurotransmission?
The membrane begins to repolarise
138
What happens after a membrane has been repolarised during neurotransmission?
It becomes hyperpolarised.
139
What leave cells during membranal repolarisation?
K+ ions
140
What happens after a cell membrane has been hyperpolarised?
It returns to its resting state.
141
What happens after an action potential has taken place?
There is a refractory period.
142
Are neuronal cell membranes permeable, impermeable, or semi-permeable?
Semi-permeable
143
What are neurones?
Information-processing devices
144
What happens during electrical neurotransmission?
Following sufficient stimulation of a neurone, an action potential is generated at the origin of the axon.
145
What happens during chemical neurotransmission?
When an action potential reaches an axon terminal, it stimulates the release of chemical neurotransmitters.
146
What are the 2 forms of neural communication?
Electrical neurotransmission & chemical neurotransmission.
147
What are synapses?
Gaps between neurones where signals are passed from 1 to the other during neural communication.
148
What are gap junctions?
Very small gaps (2-4 nm) between 2 neurones that occur in electrical synapses.
149
Which membranes have large channels that allow ions to move directly from 1 cell to the other in electrical synapses?
Those facing each other.
150
What is similar to action potential conduction along the axon?
How information is transmitted from 1 neurone to the other in electrical synapses.
151
Is neural communication across electrical synapses very fast or very slow?
Very fast (there's no time delay)
152
What are rare in the human CNS?
Electrical synapses
153
What is the mechanism of neural communication in the CNS?
Chemical synapses
154
What are chemical synapses?
Structures specialised for the transmission of chemical signals from 1 neurone (presynaptic neurone) to another (postsynaptic neurone)
155
What is the synaptic cleft?
The gap between the axon of 1 neurone & the dendrite of the next one in chemical synapses.
156
How big is the synaptic cleft?
It's small (20-40 nm)
157
How many chemical synapses does each neurone typically have?
Many (typically ca 1000)
158
Is neural communication via chemical synapses fast or slow?
Slow (ca 1 ms)
159
What do neuronal dendrites look like?
Squiggly, tree-like appendages.
160
What do neuronal cell bodies look like?
They're spherical with rugged edges & a sphere in the middle.
161
What do neuronal axons look like?
Long, thin, cylindrical structures.
162
What do the terminal branches of neuronal axons look like?
Frog-foot looking, including spherical structures with blobs at the end.
163
What does neuronal myelin sheath look like?
Sausage-shaped, long, cylindrical structures.
164
What does a complex neural network look like?
A grid of star-shaped structures with spheres in their centres, joined by long structures.
165
What does the brain look like?
It's light pink with big wrinkles all over.
166
What does the POS look like?
A long, squiggly line across the back of the brain.
167
What does the PON look like?
A horizontal line across the back of the brain.
168
What does the posterior part of the brain look like?
A squiggly, fat, tri-layered structure.
169
What does the anterior part of the brain look like?
A lobed structure consisting of fat squiggles.
170
What does the superior part of the brain look like?
A thin layer consisting of fat squiggles.
171
What do microtubules look like?
Very thin, long cylindrical structures.
172
What does a presynaptic neurone look like?
A frog foot, with a tube connected to a blob.
173
What does cytoplasm look like?
An orange-pink-coloured blank space filling up a hollow area.
174
What does a mitochondrion look like?
A bean-shaped structure with squiggly lines & cytoplasm inside
175
What does the gap junction in an electrical synapse look like?
Lines running vertically across 2 adjacent horizontal lines.
176
What connects the presynaptic neurone & the postsynaptic neurone in an electrical synapse in order for neurones to communicate?
A gap junction
177
What do postsynaptic neurones look like?
A solid-looking structure with an indent to accommodate the presynaptic neurone & bits flowing off to either side.
178
What does the presynaptic membrane of an electrical synapse look like?
2 lines with blue space in between.
179
What does a gap junction channel look like?
2 adjacent, pink structures with hollow centres.
180
What does the postsynaptic membrane of an electrical synapse involved in neural communication look like?
2 lines with blue space in between.
181
What do synaptic vesicles involved in neural communication look like?
White circles surrounded by a membrane & filled with small dots.
182
Do synaptic vesicles involved in neural communication exist in electrical synapses, chemical synapses, or both?
Chemical synapses
183
Do gap junctions involved in neural communication exist in electrical synapses, chemical synapses, or both?
Electrical synapses
184
Do microtubules exist in electrical synapses, chemical synapses, or both?
Both
185
Does cytoplasm exist in electrical synapses, chemical synapses, or both?
Both
186
Do mitochondria exist in electrical synapses, chemical synapses, or both?
Both
187
Are the presynaptic neurones involved in neural communication existent in electrical synapses, chemical synapses, or both?
Both
188
Are the postsynaptic neurones involved in neural communication existent in electrical synapses, chemical synapses, or both?
Both
189
Is postsynaptic membrane existent in electrical synapses, chemical synapses, or both?
Both
190
Is presynaptic membrane existent in electrical synapses, chemical synapses, or both?
Both
191
What fuse with postsynaptic membrane in chemical synapses?
Synaptic vesicles
192
What does the presynaptic membrane of a chemical synapse look like?
2 lines with blue space in between, forming semi-spherical shapes when vesicles fuse with them.
193
What does the synaptic cleft of a chemical synapse look like?
Blue space with membrane above & below it & differently coloured dots inside it.
194
Where is the synaptic cleft of a chemical synapse positioned?
In between the presynaptic & postsynaptic membranes.
195
What do the postsynaptic neurotransmitter receptors involved in chemical synapses look like?
Yellow bars attached to each other that open when in contact with neurotransmitters.
196
What happens when an action potential reaches a presynaptic neurone of a chemical synapse?
Vesicles filled with neurotransmitters move towards the axon terminal.
197
What do the neurotransmitters involved in neural communication look like?
Small, spherical, shiny structures.
198
What happens after vesicles fuse with the cell membrane of a presynaptic neurone?
Its contents (neurotransmitters) are released into the synaptic cleft.
199
What do neurotransmitters bind with in chemical synapses?
Receptors
200
What happens after neurotransmitters have bound with receptors in chemical synapses?
Certain ion channels open/ close, producing a localised change in membrane potential.
201
What are neurotransmitters synthesised from?
Precursors under the influence of enzymes.
202
What do neurotransmitters being synthesised look like?
4 parts of a sphere joining together.
203
What are neurotransmitters stored in during neural communication?
Vesicles
204
What do synthesising enzymes look like?
Red, thin spirals
205
What do neurotransmitter precursors look like?
4 separate parts of a sphere.
206
What destroy neurotransmitters that have leaked from their vesicles?
Degrading enzymes
207
What do degrading enzymes look like?
Red, thin zig-zags
208
What does the destruction of neurotransmitters look like?
A yellow ring with spheres inside & zigzags around the outside.
209
What causes vesicles to fuse with a synapse & release neurotransmitters?
An action potential
210
What do autoreceptors involved in neural communication look like?
Green, solid structures with spherical indents inside.
211
How many neurotransmitters released by vesicles bind with autoreceptors, inhibiting subsequent neurotransmitter release?
Some
212
What does a neurotransmitter-autoreceptor bond look like?
A green, solid structure with a spherical indent inside, filled by a sphere.
213
Once some neurotransmitters have bound with autoreceptors, what happens to the rest?
They bind to synaptic receptors.
214
What does a neurotransmitter-synaptic receptor bond look like?
A sphere in between 2 linear, purple structures.
215
How are released neurotransmitters deactivated?
Either by reuptake or enzyme degradation.
216
What does point-to-point neural communication restrict?
Synaptic communication
217
How does hormonal communication take place?
By the secretion of chemicals into the bloodstream so they can reach & affect the entire body.
218
What do the interconnected neurones of the ANS do?
They simultaneously control responses in many organs.
219
How do diffuse modulatory systems work?
They involve specific neurotransmitters & can regulate arousal, mood, motivation, sexual behaviour, emotion, sleep, and more.
220
Which systems of neural communication have a widespread influence?
The hormonal system, the system of interconnected neurones of the ANS, & diffuse modulatory systems.
221
What does the hormonal system of neural communication look like?
A system of pink tubes with black dots inside, all moving in the same direction.
222
What do interconnected neurones involved in the ANS look like?
Yellow balls connected by linear structures with cone-like structures at the end of each.
223
What do diffuse modulatory systems look like?
1 yellow ball connected by linear structures to many yellow balls.
224
What does a neurone (nerve cell) look like?
A spherical structure with a small sphere in its centre, with branches protruding from it.
225
What does an action potential look like?
A small, red zigzag.
226
What may target cells retrieving neurotransmitters look like?
Edged, blob-like structures with a sphere in their centres.
227
What type of cells may retrieve neurotransmitters from neurones?
Target cells
228
What does an endocrine cell look like?
An edged, blob-like structure with a sphere in its centre.
229
What are released from endocrine cells into blood vessels?
Hormone molecules
230
What do hormone molecules look like?
Small, red spheres.
231
What does a hormone-receptor molecule look like?
A rigid, pink structure with an indent in it.
232
What move from blood vessels to hormone receptor molecules?
Hormones
233
How does neuronal communication take place?
An action potential occurs inside of a neurone, & causes neurotransmitters to be released, then associated with neurotransmitter receptor molecules on a target cell.
234
How does hormonal communication take place?
Hormones are released from endocrine cells into blood vessels, where they're transported, then released to associate with hormone receptor molecules on target cells.
235
Which neuroscientific technique has a low spatial resolution?
EEGs
236
What do electroencephalogram (EEG) signals reflect the activity of?
Populations of neurones
237
Which neuroscientific technique requires magnetic fields?
fMRIs
238
What are sensory systems?
Parts of the nervous system responsible for processing sensory information
239
What does a sensory system consist of?
Sensory receptors, neural pathways & the sensory areas of the brain.
240
What is an example of a tactile receptor?
A Pacinian corpuscle
241
What does a Pacinian corpuscle look like?
A fingerprint-like structure, with a root-like structure protruding from it & 2 white lines in its centre.
242
What is an example of a neural pathway?
The somatosensory pathway
243
What does the somatosensory pathway look like?
A system of blue, curved, interconnected lines
244
What does a cross-section of the medulla oblongata look like?
An immature butterfly shape with 4 petal shapes towards its rear & an ovular shape towards its front.
245
What does the coronal plane of a brain look like?
2 broccoli-shaped lobes interconnected, with a butterfly shape in its centre & a thick border.
246
What does the primary somatosensory cortex look like?
A thick, broccoli-shaped border.
247
What does a third-order neurone look like?
A blue, thin line.
248
What connects the thalamus & the primary somatosensory cortex?
A third-order neurone
249
What do dorsal column nuclei look like?
Dark brown, petal-shaped structures located in the medulla oblongata.
250
What do dorsal column nuclei look like?
Dark brown, petal-shaped structures located in the medulla oblongata.
251
What does a second-order neurone look like?
A long, blue, thin line.
252
What does the decussation of the medial lemniscus look like?
A small, ovular structure located in the medulla oblongata.
253
Where do second-order neurones run through?
The dorsal column nuclei & decussation of the medial lemniscus
254
What do dorsal columns look like?
2 indented, 'butt-like' appendages of the spinal cord & medulla oblongata.
255
What type of neurones make up the dorsal root ganglion?
First-order neurones
256
What do second-order neurones connect to in the somatosensory system?
First- & third-order neurones
257
Where are dorsal columns located?
In the spinal cord
258
What type of neurones are first-order neurones?
Afferent
259
What type of receptor is a Meissner's corpuscle?
A mechanoreceptor
260
What do Meissner's corpuscles look like?
They are ovoid with 3-dimensional squiggles & a hollow space inside.
261
What type of receptor is a muscle spindle?
A proprioceptor
262
What do muscle spindles look like?
4 tubes laying alongside each other in a circular arrangement.
263
What do first-order neurones connect to in the somatosensory system?
Either mechanoreceptors/ proprioceptors
264
What are 2 examples of the sensory areas of the brain?
The primary & secondary cortexes
265
What does the primary somatosensory cortex (SI) look like?
A thick squiggle on each side of the brain.
266
What does the posterior parietal cortex (PPC) look like?
A round patch on each side of the brain
267
What does the secondary somatosensory cortex (SII) look like?
A circular patch in the centre of the side of the brain.
268
What does the central sulcus look like?
A squiggly line running down part of each side of the brain.
269
What contains the SI?
The postcentral gyrus
270
What does the postcentral gyrus look like?
A thick squiggle down the centre of the brain.
271
What is an example of sensory encoding?
Sensory transduction
272
What does sensory processing start with during sensory encoding?
Receptor cells
273
What are receptor cells specialised for?
Detecting particular energies/ chemicals.
274
When do receptor cells convert detected energy into a change in membranal electrical potentials?
When they're exposed to a stimulus
275
What is sensory transduction?
The conversion of sensory signals into electrical signals via the depolarisation of sensory neuronal membranes upon the stimulus of a receptor.
276
What happens after a signal has been detected during sensory encoding?
It's collected.
277
What happens after a signal has been collected during sensory encoding?
It's transduced
278
What happens after a signal has been transduced during sensory encoding?
It's processed
279
What happens after a signal has been processed during sensory encoding?
Action takes place
280
What determines the form of energy to which a receptor will respond during sensory encoding?
The receptor's structure
281
What does a node of Ranvier look like?
A notch between sausage-shaped structures along a linear structure.
282
Do neurones typically have 1 or more nodes of Ranvier for sensory encoding?
More than 1
283
What does the receptor membrane of a neurone look like?
A smooth, linear structure preceded by a portion of axon with nodes of Ranvier.
284
When do receptor potentials occur?
In between the arrival of stimulus energy at the receptor cell & the initiation of an action potential.
285
Are the receptor potentials that occur during sensory encoding usually EPSPs or IPSPs?
EPSPs
286
Do the receptor potentials that occur during sensory encoding align with stimulus exposure or are these independent of each other?
They align with stimulus exposure.
287
When does an action potential occur?
When receptor potentials reach a certain threshold.
288
Do we respond to sensory stimuli of a wide or narrow range of intensities?
A wide range
289
Why do multiple receptor cells act in a parallel manner during sensory encoding?
To provide a broader range for coding the intensity of a stimulus.
290
What happens as the strength of a stimulus increases?
New neurones are recruited to encode sensory information.
291
How can intensity be represented?
By the number of activated cells.
292
What is range fractionation?
The specialisation of different receptors for the encoding of particular fractions of an intensity scale.
293
Which experimental setup could be used to analyse neural activity?
2 amplifiers (A & B) could be placed inside the head of a cat & 2 receptive fields identified (e.g. in the forelimb for cortical neurone A & tail for cortical neurone B).
294
What could a receptive field on a cat's forelimb look like?
3 circles, 2 smaller ones inside of 1 big one, each of different colour.
295
What could a receptive field on a cat's tail look like?
3 circles, 2 smaller ones inside of 1 big one, each of different colour.
296
In a receptive field on a cat's forelimb, what would the associated cortical neuronal activity of the outer ring be like?
Medium
297
In a receptive field on a cat's forelimb, what would the associated cortical neuronal activity of the middle ring be like?
Low
298
In a receptive field on a cat's forelimb, what would the associated cortical neuronal activity of the inner ring be like?
High
299
In a receptive field on a cat's tail, what would the associated cortical neuronal activity of the outer ring be like?
Medium
300
In a receptive field on a cat's tail, what would the associated cortical neuronal activity of the middle ring be like?
Low
301
In a receptive field on a cat's tail, what would the associated cortical neuronal activity of the inner ring be like?
High
302
What happens to many receptors during sensory encoding when stimulation is maintained?
They show a progressive loss of response.
303
What is sensory adaptation?
When receptors show a progressive loss of response when stimulation is maintained during sensory encoding.
304
What happens to receptor potential between the time that it's exposed to a stimulus (higher stimulus strength) & the time that it's no longer exposed to a stimulus (lower stimulus strength) in slowly-adapting receptors during sensory encoding?
It rapidly increases, before gradually decreasing.
305
What happens to receptor potential between the time that it's exposed to a stimulus (higher stimulus strength) & the time that it's no longer exposed to a stimulus (lower stimulus strength) in rapidly-adapting receptors during sensory encoding?
It rapidly increases, then rapidly decreases, before remaining level, then rapidly decreasing & increasing again (off response).
306
What is the order of the visual pathway?
Eye, retina, thalamus, lateral geniculate nucleus (LGN), primary visual cortex (striate cortex, V1) & secondary visual cortex
307
What do visual fields look like?
Circular spaces with halves of different colours.
308
What do eyes look like?
Spherical structures with bulges & 1 small bubble at the front.
309
If you see the colours blue & green in your visual field, which colours will be picked up by the retina?
Blue & green
310
What travels from the retina to the optic chiasma?
The optic nerve
311
What does the optic nerve look like?
A long, thin linear structure.
312
What does the optic chiasma look like?
A cross-shaped structure enclosing 4 linear structures (optic nerves) of 2 different colours.
313
What connects the optic chiasma & the lateral geniculate body?
The optic tract
314
What do optic radiations look like?
2 long, thin linear structures.
315
What connects the lateral geniculate body & the striate area?
Optic radiations
316
What detect different types of tactile sensation?
Tactile mechanoreceptors
317
How many different types of tactile mechanoreceptor are there?
4
318
What are the 4 different types of tactile mechanoreceptors?
Pacinian corpuscles (vibration), Meissner's corpuscles (touch), Merkel's discs (touch), & Ruffini's endings (stretch)
319
What do Pacinian corpuscles look like?
Large green leaves, with circular lines on them.
320
What do Meissner's corpuscles look like?
Pink, hairy bundles with squiggles at the ends.
320
What do Merkel's discs look like?
Narrow, purple tubes with blobs at the end.
321
What do Ruffini's endings look like?
Thick purple structures with blue squiggles running through them.
322
What are the characteristics of the receptive fields of Pacinian corpuscles?
They are large with vague borders
323
What are the characteristics of the receptive fields of Meissner's corpuscles?
They are small with sharp borders.
324
What are the characteristics of the receptive fields of Merkel's discs?
They are small with sharp borders.
325
What are the characteristics of the receptive fields of Ruffini's endings?
They are large with vague borders.
326
What are 2 potential stimulus-response properties?
Fast- or slow-adapting receptors.
327
Are Pacinian corpuscles fast-/ slow-adapting?
They're fast-adapting
328
Are Meissner's corpuscles fast-/ slow-adapting?
They're fast-adapting
329
Are Merkel's discs fast-/ slow-adapting?
They're slow-adapting
330
Are Ruffini's endings fast-/ slow-adapting?
They're slow-adapting
331
What would the action potentials involved in a fast-adapting receptor look like?
There would be concentrated lines either side of a large gap in the centre.
332
What would the action potentials involved in a slow-adapting receptor look like?
There would be evenly-spaced vertical lines across 1 horizontal line.
333
Which order does the tactile pathway occur in?
It starts with mechanoreceptors, then moves along to the dorsal column & thalamus, before moving to primary & secondary somatosensory cortexes (S1 & S2), & ending with the associative areas (e.g. the parietal lobe).
334
What does a cross-section of the midbrain look like?
A relatively thin, butt-shaped, light-coloured structure.
335
What does the posterior column of the spinal cord look like?
4 stretched-out, rounded, diamond-shaped structures.
336
What does a spinal nerve look like?
2 tubes, 1 with a bulge in the middle, converging into 1 unified tube.
337
What can be found in the midbrain?
The medial lemniscus & the second neurone.
338
Where are spinal nerves located?
Either side of the spinal cord.
339
What do the nuclei of the medulla look like?
4 separate rounded, diamond-shaped structures.
340
Where is the somatosensory homunculus located?
In the primary somatosensory cortex (S1)
341
What is the somatosensory homunculus?
A distorted representation of the human body, based on a neurological "map" of the areas & proportions of the human brain dedicated to processing tactile signals for different parts of the body.
342
What is 1 way in which the somatosensory homunculus can be visually represented?
As a man with disproportional features, such as a man with a much larger tongue than foot.
343
Which order does the auditory (hearing) pathway occur in?
It starts with the cochlea, then moves along to the auditory (cochlear) nerve & the olivary nucleus (brainstem), before moving to the inferior colliculus & medial geniculate nucleus (thalamus), & ending with the auditory cortex.
344
What does the cochlea look like?
A shell-like structure, with a spiral-shaped component & several loop-shaped components.
345
Which structures run in between the cochleae & the ventral cochlear nuclei?
Cochlear nerves
346
What does a superior olive look like?
An elongated spherical structure located at the tip of the brainstem.
347
What does an inferior colliculus look like?
A small globular structure in the midbrain.
348
What does a medial geniculate nucleus look like?
A large orbed structure located in the thalamus.
349
What do the dorsal cochlear nuclei connect to
The inferior colliculi & cochlear nerves
350
What do the inferior colliculi connect to?
The dorsal cochlear nuclei, the superior olives, & the medial geniculate nuclei.
351
What do the medial geniculate nuclei connect to?
The inferior colliculi & auditory cortexes.
352
Which pathway is associated with the sense of touch?
The tactile pathway
353
Which pathway is associated with the sense of hearing?
The auditory pathway
354
Which pathway is associated with the sense of balance?
The vestibular pathway
355
Which order does the vestibular pathway occur in?
It starts with vestibular receptors, then moves along to the brainstem & the cerebellum, before moving to the thalamus, & ending with the vestibular areas.
356
What are rods & cones receptors for?
Vision
357
What area acts as a sensory relay?
The thalamus
358
What do the semicircular canals respond to?
Angular acceleration
359
Is there a unimodal vestibular cortex or a vestibular cortical network?
A vestibular cortical network.
360
Does the vestibular cortical network have a unique or bland anatomical arrangement?
A unique one
361
Which areas of the brain are associated with the vestibular cortical network?
The somatosensory cortex, premotor cortex, anterior insula, posterior parietal cortex, temporoparietal junction (TPJ), & hippocampus.
362
How are different levels of motor control systems organised?
Hierarchically
363
In relation to motor control, what controls skeletal muscles in response to sensory information (reflexes & voluntary movements)?
The spinal cord
364
What does the brainstem do once it's integrated motor commands from higher levels of the brain?
It transmits them to the spinal cord.
365
Which structure initiates motor commands?
The primary motor cortex.
366
In addition to the primary motor cortex, what is a source of motor commands?
The non-primary motor cortex.
367
How are motor control systems organised from most to least important?
The spinal cord is the most important, then the brainstem, then the primary motor cortex, & the non-primary motor cortex is the least important.
368
Which motor control systems do the primary & non-primary motor cortexes communicate with, as well as communicating with each other?
The spinal cord, brainstem, cerebellum, & basal ganglia.
369
Which motor control systems does the thalamus communicate with?
The primary & non-primary motor cortexes
370
Which motor control systems does the cerebellum communicate with?
The thalamus & brainstem.
371
Which motor control systems does the brainstem communicate with?
The spinal cord; & muscles of the head, neck, & face.
372
Which motor control systems does the spinal cord communicate with?
The muscles of the body
373
Which motor control system do the basal ganglia communicate with?
The thalamus
374
What is 1 cortical area involved in motor control?
The primary motor cortex (M1)
375
Which structures, other than M1, are involved in motor control?
The basal ganglia & cerebellum.
376
What are the basal ganglia?
A group of subcortical forebrain nuclei (consisting of the caudate nucleus, putamen/ striatum, globus pallidus, & subthalamic nucleus)
377
What do basal ganglia modulate in relation to motor control?
Patterns of motor activity.
378
What does the cerebellum control?
Neural "programmes" for the execution of skilled movements & motor learning.
379
What activity does electromyography record?
The activity of individual muscles/ muscle fibres during action.
380
What are the striatum (caudate & putamen), & the globus pallidus?
Basal ganglia
381
What is the main neurotransmitter involved in the muscular junction?
Acetylcholine
382
What influence emotional expression?
Brain lesions
383
What is a neural correlate of emotion?
The Papez circuit (aka, the limbic system)
384
What can the destruction of a set of interconnected pathways in the brain impair?
Emotional processing
385
Which structures of the brain are involved in the Papez circuit?
The fornix, neocortex, cingulate cortex, anterior nuclei of the thalamus, hypothalamus, & hippocampus.
386
What does the fornix look like?
A thin, curled tube.
387
What does the neocortex look like?
A thick, bumpy, pink layer of the brain.
388
What does the cingulate cortex look like?
A "C"-shaped, bumpy inner layer of the brain.
389
What do the anterior nuclei of the thalamus look like?
Small, globular structures in the middle of the brain.
390
What does the hippocampus look like?
A "C"-shaped tube running along the bottom area of the brain.
391
Which structure does the neocortex directly interact with?
The cingulate cortex
392
Which structures does the cingulate cortex directly interact with?
The neocortex & the hippocampus
393
Which structure does the hippocampus directly interact with?
The hypothalamus
394
Which structures does the hypothalamus directly interact with?
The anterior nuclei of the thalamus
395
Which structure do the anterior nuclei of the thalamus directly interact with?
The cingulate cortex
396
What is the neocortex responsible for?
Emotional colouring
397
What is the cingulate cortex responsible for?
Emotional experience
398
Which structure enables communication between the hippocampus & hypothalamus?
The fornix
399
What is the hypothalamus responsible for?
The expression of emotion
400
What is an example of the fear conditioning paradigm?
A rat being placed in a box with a grid underneath, & a sound being played inside of the box- when the sound occurs the second time, the grid is electrified,- when the rat hears the sound the third time, it's scared of the sound (increase in blood pressure).
401
What is the amygdala involved in?
The processing of fear.
402
What characterises the Kluver-Bucy syndrome?
The lack of fear/ aggression.
403
What does the nucleus accumbens release?
Dopamine
