Neurophysiology Flashcards
1
Q
Nerve type
A
Afferent
2
Q
Nerve type
A
Efferent nerve
3
Q
Autonomic nervous system
A
Visceral motor (involuntary) function
4
Q
Somatic nervous system
A
Somatic motor (voluntary) function
5
Q
Glial cells
A
- Non-neuronal cells
- Provide support + nutrition
- Form myelin
6
Q
What characterises a neuron?
A
- Electrical excitability
- Presence of synapses
7
Q
Name the three parts of a typical neuron
A
- Soma/body
- Dendrites
- Axon
8
Q
The axon leaves the soma at the…
A
Axon hillock
9
Q
Give the 5 functions of glial cells on neurons
A
- Secure
- Supply oxygen + nutrients
- Insulate between neurons
- Destroy pathogens
- Remove dead neurons
10
Q
Resting membrane potential
A
- Potential gradient
- Between IC space and EC space
11
Q
The potential of the IC space is…
A
Negative
12
Q
Steps toward depolarisation of a cell
A
- Positive IC charge
- Decreased PD between IC and EC
13
Q
Give the potential difference found between the IC + EC space of a neuron
A
-75mV
14
Q
A
- Na+: 140
- K+: 5
- Ca2+: 2.5
- Cl-: 100
15
Q
A
- Na+: 14
- K+: 95
- Ca2+: μmol/l
- Cl-: 3
16
Q
A
ATPase pump
- Na+ out
- K+ in
17
Q
A
K+
18
Q
A
Na+
19
Q
RMP is a result of…
A
Outflow of K+ ions
20
Q
Give the aim of the ATPase pump in the neuron cell membrane
A
Maintain concentration gradient
21
Q
Which equation is used to calculate the change of permeability of a neuron
A
Goldman-Hodgkin-Kats (GHK) equation
22
Q
EK
A
Potassium equilibrium potential
23
Q
The lipid bilayer of a cell functions as an electrical…
A
Insulator
Ions pas via the channels
24
Q
1
A
Channel domains
25
2
Outer vestibule
26
3
Selectivity filter
27
5
Phosphorylation site
28
Hyperpolarisation never evokes...
Action potential
29
Local response
A potential change remaining under a threshold
30
What is conduction with decrement?
* The farther the recording electrode from the stimulation site
* The smaller the potential change which reaches the electrode
31
Give the types of synaptic signals?
* Excitatory
* Inhibitory
32
Source of action potential
Voltage-dependent ion channels
33
Sodium influx persist until depolarization reaches...
15-30mV
34
Give the process
1. MP at _-70mV_ (RMP)
2. Stimulus → MP raised to _-55mV_ (Threshold potential)
3. MP raises to _+40mV_
4. Potential drops + overshoots to _-90mV_
5. MP at _-70mV_ (RMP)
35
'All or nothing' law
The strength at which a nerve responds to a stimulus is independent from stimulus strength
36
Tetrodotoxin (TTX)
* Fish toxin
* Blocks voltage-dependent sodium channel
37
The specific blocker of the voltage-dependent K+ channel
Tetraethyl ammonium (TEA)
## Footnote
*Channel is either closed or open (no inactive state)*
38
Title the figure
Phase 0: Stimulation
39
Title + Annotate the figure
Phase 1: Threshold potential
* Voltage-dependent Na+ channel opens
40
Title + Annotate the figure
* Phase 2: Overshoot, Na+ channel inactivates
* Phase 3: Plateau, slow Ca2+ influx
41
Title + annotate the figure
Phase 4
* Repolarisation, K+ efflux
42
Title + Annotate the figure
Phase 5: Posthyperpolarisation
* Voltage dependent Na+ + K+ channels close
* ATPase pump restores conc. gradient
43
Describe propagation of AP in naked fibres
* AP propagates step-by-step
* Channel activates the next channel
* Slow process
44
AP decreases
45
AP regeneration
46
Fast conduction with myelinated fibres is made possible by the fact that...
Only the nodes of Ranvier contain the TTX-sensitive sodium channels
47
Conduction velocity of myelinated fibres is proportional to...
Diameter of the myelin sheet
48
What are the classifications of nerve fibres?
* Erlanger-Gasser
* Lloyd-Hunt
49
Give the steps of axonal transport
1. Peptides/neurotransmitters produced in the soma of the neuron
2. These are then transported to the presynaptic nerve ending
50
Which motor proteins are involved in the movement during axonal transport?
* Kinesin
* Dynein
51
Dynein + kinesin are powered by...
Hydrolysis of ATP
52
Kinesin transports substance...
* From the centre to the periphery
* Known as anterograde transport
53
Dynein transports substance...
Toward the negative end of microtubules
54
Compared with chemical synapses, electrical synapses are...
* Fast reflex arches
* Often bidirectional
## Footnote
*Used to give fast responses, such as defensive reflexes*
55
Chemical synapses usually communicate with...
Muscles or glands
56
Name the connection of an _electrical_ synapse between two neurons
Gap junction
57
Metabotropic effect
Long term changes by activating signalling cascades
(Via chemical synapses)
58
Give the steps of metabotropic effect
1. Binding of ligand to the receptor
2. IC second messenger
3. IC metabolic (metabotropic) effect
4. Long lasting depolarisation or hyperpolarisation
59
Give the synaptic processes of metabotropic effect
* Facilitation
* Inhibition
* Disfacilitation
* Disinhibition
* Spatial summation
* Temporal summation
60
The synaptic processes of metabotropic effect can lead to which kinds of potential?
* EPSP (Excitatory postsynaptic potential)
* IPSP (Inhibitory postsynaptic potential)
61
Which transmitters are involved in metabotropic effect?
Metabotropic transmitters
62
How do ion channels alter the flow of cations/anions?
By augmenting/attenuating ion permeability
63
List the types of ligand-dependent ion channels
* n-ACh
* Glutamate
* Anion
* G-protein mediated
64
List the types of ion channel
* Leaking Na+, K+ and Cl-
* Voltage-dependent Na+ and K+
* Ligand-dependent non-selective Na+, K+ and Cl-
* Mechano receptive
* Energy sensor
65
What acts as a stimulus of mechanoreceptive ion channels?
Deformation of an axon terminal
66
What acts as a stimulus of energy sensor ion channels?
ATP concentration of a cell
67
Describe the structure of the voltage-dependent Na+ channel
* IC, EC and transcellular parts
* Domains I-IV
* These join to form a closed channel
68
Which ion channel segment changes its conformation when the membrane potential is detected
* 4th Membrane segment of each domain
* Causes an open state of the channel
69
n-Ach channel is located...
* Neuromuscular junction
* CNS
70
n-Ach delta subunit binds...
d-tubocurarine
71
Give the stimulators and inhibitors of n-Ach
* Nicotine (+)
* Curare (-)
72
Summarise: Glutamate-dependent cation channels
* Important excitatory system
* Depolarisation after a small Na+ influx
* LTP (Long-term potentiation) found here
* Basis of learning
73
The opening of anion channels causes
Hyperpolarisation
74
Give the mediators of Anion channels
* GABA
* Glycine
75
In ryanodine channels, the T-tubulus/ triad is blocked by...
Dihydropyridine (DHP)
76
The pore-forming part of the DHP receptor acts only as a...
Voltage sensor
77
Title the figure
Calcium channel in the skeletal muscle
78
Ryanodine channel in the SR membrane
79
DHP channel (=voltage sensor) in the T-tubulus
80
IP3 receptor function
Mobilises Ca2+ from IC stores
81
Describe Energy sensor ion channels
* Low ATP = Open channel
* High ATP = Closed
82
Describe the mechanism of high ATP levels on energy sensor channels
1. Regulator subunit - Conformational change
2. Pore-forming subunits - Conformational change
3. K+ efflux terminates
4. IC K+ increases
5. Depolarisation
6. Ca2+ influx
83
The electrical stimuli applied to tissue can be described by...
* Potential
* Length of time it is applied
84
Adaptation
* Stimulation potential reached slowly
* The opening of Na+ channels
* Inactivation of Na+ channels
* Inhibition of Na+ influx
85
Summation
* Sub-threshold stimuli applied frequently
* AP may be triggered by this weaker-than-threshold potential
* (Accumulation of cations)
86
Rheobase
The minimal stimulus strength that is able to generate a response
87
Chronaxie
The _time_ necessary to elicit a response if the stimulus strength is _set to double the value of rheobase_
88
Give the layers of a nerve, starting from the inside
1. Axon
2. Endometrium
3. Perineurium
4. Epineurium
89
Give the classifications of neurons
* Unipolar
* Bipolar
* Multipolar
* Pseudounipolar
90
Unipolar neuron
Dendrite + axon emerges from the same process
91
Bipolar neuron
Axon + single dendrite on opposite ends of the soma
92
Multipolar neuron
Two or more dendrites separate from the axon
93
Pseudounipolar neuron
Unipolar, but with one divided axon
94
Neural network
* Organised for complex tasks
* The function of one neuron may be influenced by the functions of others (Convergence)
* Axons of one neuron may to many other neurons (Divergence)
95
Function of interneurons
* May inhibit/excite collaterals between neural pathways
* May generate returning signals (_Reverberation_)
96
Types of reflexes
* Monosynaptic: One synapse responsible
* Polysynaptic: More than two neurons responsible
97
Presynaptic inhibition
Inhibition acts on the region before the second neuron
98
Postsynaptic excitation
The second neuron is influenced by the excitatory or inhibitory effects
99
Disfacilitation
100
Disinhibition
101
The spinal cord is split into which elements?
* Consciously perceived
* Somatic
* Subconscious, automatic
102
The simplest unit of a function is the...
Reflex
103
White matter + Grey Matter
* White matter: Nerve fibres
* Grey matter: Nerve cells
104
In a cross-section of a grey matter, what can be distinguished?
Rexed's zones
(With the exception of the lateral horn)
105
Give the Rexed's zones/fields
* I-VI = Upper horn
* VII-IX = Lower horn
* II-III → Mostly interneurons
* IX → Large motor neurons
106
In Rexed's zones, motor cells show what kind of arrangement?
Somatotopic arrangement
107
Describe the size principle of zones in the ventral horn
* Postural, tonic muscles are innervated by a low threshold, _small_ neurons
* Neurons associated with complicated movements are _large_
108
Cells leaving the vertebral canal are called...
Radicular cells
109
List the types of radicular cell
1. Somatosensory cells
2. Somatomotor cells
3. Sympathetic cells
4. Parasympathetic cells
110
Give the cells inside the grey matter
* Excitatory interneurons
* Inhibitory interneurons
111
Segments of the skin associated with a sensory nerve
Dermatomes
## Footnote
*Important for determination of the origin of skin sensitivity disturbances*
112
Skin zones belonging to a visceral organ are called...
Head-zones
## Footnote
*Known as referred pain*
113
Give the types of reflex
* Spinal cord reflex
* Cranial nerve reflex
* Primitive reflex
114
Steps of a reflex arc
1. Stimulus
2. Sensory neuron activated
3. Processing in CNS
4. Motor neuron activated
5. Response by effector
115
Reflex when the receptor is found in the same organ/muscle as the effector
Proprioceptive reflexes
116
Give the main types of proprioceptive reflex
* Myotatic
* Inverse myotatic
* Stretch evoked flexor reflexes
117
How does the _proprioceptive reflex_ differ from the exteroceptive reflex
1. Reflex arc is monosynaptic
2. No latency
3. Immediate response
4. No fatigue
118
Common features of the proprioceptive reflexes + exteroceptive reflexes
* The response has a local character
* Response intensity is proportional to stimulus
* Reciprocal innervation is typical
* Higher brain levels modulate the reflex
119
Myotatic (stretch) reflex receptors are located...
* 2 sites in the intrafusal fibre:
* Nuclear bag
* Nuclear chain
120
The receptors of the myotatic reflex synapse directly + through excitatory interneurons to the...
* Alpha motor neuron of the corresponding extrafusal fibre
121
Antigravitational musculature
Extensor/flexor reflex (seen in sloth)
## Footnote
*Reflectorial contraction*
122
The most important connections of afferents coming from the muscle spindle...
Alpha motorneurons
123
Fine tuning of the myotatic reflex is completed by...
Recurrent inhibition
124
The function of Renshaw cells
Cause retrograde inhibition
*Strong afferent effects are smoothed*
125
Inverse stretch/inverse myotatic reflex
1. Passive stretching of Muscle → Contraction (Fusimotor system)
2. Further stretching → _Sudden relaxation_ (lengthening)
126
Which organs are activated in the inverse myotatic reflex?
Golgi tendon organs
127
The function of the inverse myotatic reflex
* Protection against overstretching and rupture
* Fine-tuning roll in normal movement
128
Beside Golgi tendon organs, what else can explain the myotatic reflex?
Active muscle contraction → Antagonising the fusimotor system
129
Flexor stretch reflex
Extension both in extensor and flexor muscles
130
Extensor thrust
* Pressing the sole of the foot on the ground extends the limb
* Ensures a reliable support during stepping
131
Exteroceptive reflexes
Reflex arc found outside of the effector organ
* Averting
* Nociceptive
* Pain avoiding behaviour
132
How does the _exteroceptive reflex_ differ from the proprioceptive reflex?
* Tactile + pain receptor
* Polysynaptic
* Very long latency
* Slow response
* Easily fatigues
133
Give the pathway of an exteroceptive reflex
1. Nociceptive/thermoreceptors → Grey matter
2. Afferent activation:
1. Relaxes ipsilateral extensor muscles
2. Activated ipsilateral flexor muscles
3. Every muscle of the joint participates
134
As well as the ipsilateral muscles, the exteroceptive reflex also affects...
Contralateral muscles
135
How can reflexes be clinically used in the case of lesions?
1. Size of the lesion can be localised
2. Location of the lesion in the spinal cord can be localised
3. Lesions can cause a change in the pattern of the reflex
136
Babinski sign in a diseased animal
1. Plantar reflex (efferent has no modulating influence)
2. Forelimb is withdrawn by the animal
3. On the digits, instead of plantar flexion, _dorsiflexion is seen_
137
Give the reflexes in the 'movement patterns' category
* Walking
* Scratch reflex
138
Movement patterns
* Stereotype
* They extend to more segments
* Rhythmically repeated
* They last longer than the stimulus
139
0
Stimulus arrives from the sensory ganglion
140
1
Adaptation to excitatory effects
141
2
Spontaneous release from inhibitory effects
142
3
Running toward the extensor motor neuron
143
4
Running toward the flexor motor neuron
144
5,6
Excitatory interneurons send collaterals to inhibitory interneurons
145
Sensory ascending pathways
* Travel toward the CNS
* Consist of three neurons
146
Motor, descending pathways contain which systems?
Somatic locomotor systems:
* Pyramidal system
* Extrapyramidal system
147
Give the most important ascending pathways
* Goll-Burdach
* Flechsig
* Gowers
* Lateralis et ventralis
148
Goll-Burdach
* Light tactile sensation, motor afferents
* *Fasciculus* *gracilis* (Goll)
* *Fasciculus cuneatus* (Burdach)
149
Flechsig
Cerebellar muscle afferents: Dorsal spinocerbellar tract
150
Gowers
Cerebellar muscle afferents: Ventral spinocerebellar tract
151
Lateralis et ventralis spinothalmic tracts
Thermal and nociceptive sensory afferents
152
Pyramidal tracts
Lateral corticospinal tract + Ventral corticospinal tract
153
List the extrapyramidal tracts
* Rubro-spinal tract
* Vestibulo-spinal tract
* Reticulo-spinal tract
* Tectos-pinal tract
154
Rubrospinal tract
155
Vestibulospinal tract
156
Reticulospinal tract
157
Tectospinal tract
158
Autonomic nervous system (ANS)
* Automated control of metabolic processes
* Connection between the organism and the external environment
* Controlling:
* Smooth muscles
* Exocrine/endocrine glands
159
Efferentation of the ANS is practically independent from...
The somatic motor system
160
Why is the ANS: Autonomic?
Essentially involuntary actions
161
Why is the ANS: Vegetative?
It controls the metabolism required to maintain the life of the organism
162
What are the ANS elements in the CNS?
Supraspinal regions
163
Function of the supraspinal regions
* Perception of the actual state (Afferentation)
* Processing
* Efferentation:
* Activating sympathetic, parasympathetic endocrine systems
* Responses of the behaviour
164
* Processing of external stimuli
* Initiating behavioural responses
165
Behavioural and emotional responses
166
* Integration of internal stimuli
* Connection to the endocrine system
167
* Respiration
* Circulation
* Digestion
168
The frontal and parietal association cortex influences...
Behavioural responses related to autonomic functions
169
Which cranial nerves contain afferent and autonomic neurons?
* III
* VII
* IX
* X
170
The PNS is built upon which features?
1. Ach transmitters
2. Postganglionic neurons
3. Sympathetic neurons transmission by _norepinephrine_
4. Signals can cause opposite effects on target cells (dependent on cell surface receptors)
171
Postganglionic neurons receive information from...
* Preganglionic neurons
* Collaterals
172
Fate of ACh
* Binds to the receptor
* Metabolised by the present acetylcholinesterase enzyme
173
Function of the sympathetic nervous system
* Mobilisation
* Redistribution of blood
* Dilation of smooth muscle + vessels
* Redistribution of circulating blood
174
Title and annotate the figure
**Sympathetic postganglionic transmission**
1. Fibre reaches tissue
2. Neurotransmitters are released in varicosities along the tissue
175
Main neurotransmitter for sympathetic postganglionic fibres
Norepinephrine
* Released via _peptidergic synaptic co-transmission_
176
What occurs at the varicosity?
Place of final transmission of norepinephrine
177
Location of the sympathetic nervous system
Thoracolumbar spine segments
178
Paravertebral switch: Figure
179
Prevertebral switch: Figure
180
Functions of the parasympathetic nervous system
* Increase substance + energy stores
## Footnote
*Effects are restricted to a defined area*
181
Give the parts of the parasympathetic system
* Cranial part
* Sacral part
182
The longest fibres of the parasympathetic nervous system
Preganglionic fibres of the vagus nerve
183
The spinal parasympathetic division originates from the...
...preganglionic cells in the _intermediomedial_ _region_ of the _sacral spinal cord_
## Footnote
*Via splanchnic nerve*
184
Parasympathetic postganglionic transmission
1. ACh release from postganglionic fibre
2. _Muscarinic_ target cell receptor receives ACh
3. The effect of the ACh depends on the type of receptor (M1/2/3)
185
Give the steps of sensory signal in the CNS
1. Reception
2. Spinal cord
3. Transmission through ascending pathway
4. Signal modulation
5. Perception in the cortex
186
Pain stimuli can pass to the spinal cord via which pathways?
* Fast (A-Delta) reception
* Slow (C-fiber) (unmyelinated) reception
187
Pain sensation is based on which nerve endings?
Nociceptive free nerve endings
188
What explains the fact that slow fibres are arranged in multisynaptic connections?
Slow spreading of pain in emotional states
189
Rapid pain mainly elicits...
Flexor reflexes
190
What symptoms can be seen in slow pain responses?
* Decrease BP
* Sweating
* Nausea
191
Pain sensors receive which stimuli from an injury?
* Noxious stimulus (wound)
* Histamine (from basophil)
* Stretch stimulus (from blood vessel oedema)
192
SP =
Substance pain
193
Give the effect of SP
Multiplies the discharge of its own axons in many ways
E.g Oedema
194
How can pain be decreased/controlled?
With _Descending_ (opiate-mediated) pathways
* Pain stimulus is the same, only effect on pain-sensing structures decreases
195
Signal modulation
1. *Nucl.* *gracilis* *et* *cuneatus*
2. Cross to the opposite side to thalamic nuclei
3. Received by the relay (synaptic) nuclei
196
Give examples of relay nuclei
* VPL (Ventro postero-lateral) nucleus
* VPM (Ventro postero-medial) nucleus
197
VPL (Ventro postero-lateral) nucleus shows which organised arrangements?
* Somatotopy
* Co-localisation according to the modality of sensation
198
VPM (Ventro postero-medial) nucleus function
Receptors of the head send impulse patterns through CN-V
199
Nuclei which non-synapsin afferents run through are known as...
Bypass nuclei
200
Specific/relay system nuclei are involved in...
_Relaying_ signals to the _third order sensory neuron_
* Allows the enhancement of a stimulus
201
Non-specific/bypass system function
Determination of the pain sensation and activation state
* Less important in the exact localisation of pain
202
The non-specific/bypass system receives fibres from...
Collaterals from axons travelling to the frontal cortex
203
From the thalamus, which two kinds of afferentation reach the cortical areas?
* Somatotopically + sensation specifically arranged fibres
* Fibres from the reticular formation
204
What is the basic unit of cortical representation?
The column of grey matter
205
Brodmann areas
Regions of the cerebral cortex in the human brain defined by its structure and organisation of cells
206
Cortical somatotopy is proportional to...
The relative importance of the given area in sensation
*Not necessarily the size of the area*
207
The secondary sensory area
Sylvian fissure
208
In dogs + cats, 90% of sensory formation is occupied by...
Lips, cheek and limbs
209
Columnar functional system
1. Impulse is relayed to the cells of the columnar functional unit (usually _Cajal's double dendritic cell_)
2. Information is transmitted to large pyramidal cells
3. Information leaves through two pathways:
1. Fibres to near-by columns
2. Fibres to the periphery
210
The column that forms a functional unit contains how many cells?
2500 cells
## Footnote
*5% are pyramidal cells*
211
The origin of posture and movement control are based on...
Heirarchical organisation
212
Neurons in the spinal cord that are involved in posture are under the control of...
_Local regulatory systems_ supplimented by an additional supervisor, _director system_
213
The most important afferentation of posture
Vestibular apparatus
214
The main function of the vestibular apparatus
Support the body against gravitation
215
Give the order of voluntary movement hierarchy (upper motor system)
1. Movement initiation
2. Movement planning
3. Movement plan reconsideration
4. Movement execution
216
The control of both the posture and the voluntary movement can be divided into which levels?
* Upper motor system
* Spinal/lower motor system
217
The spinal/lower motor system is modulated by...
The upper system
It is capable of independent work
218
Postural reflexes are composed of...
* Spinal (LMS) reflexes
* Upper/supraspinal (UMS) reflexes
219
Postural reflexes perform which tasks?
1. Antigravitational support
2. The stabilisation of the centre of mass
3. Stabilise the relative position of body parts (controlled by vermis of cerebellum)
220
Which nuclei control postural reflexes?
In the brain stem:
* *Nucl. ruber*
* Nuclei of reticular formation
* Deiters nucleus
221
Deiter's nucleus and nuclei of reticular formation increase activity of...
Motor sensors of the spinal cord
222
What is the effect of cutting the connection between *nucl**.* *ruber* and Deiter's nucleus?
Disinhibition of the effects of Deiter's nucleus
* Leads to a drastic increase in extensor tone in the whole body (Increase of alpha and gamma motor neuron activity)
* Known as _Decerebration rigidity_
223
Give the symptoms of spinal shock
* Areflexia
* Hypotension
* Poikilothermia
* Irreversible loss of sensory & voluntary functions
224
Recovery from areflexia
Somatic restitution
225
Recovery from anaesthesia
Vegetative restitution
226
Give the reflex types in the UMS
1. Tonic reflexes
2. Supporting reflexes (Reflexes maintaining the upright position)
3. Statokinetic reflexes
4. Placing & hopping reflexes
227
Tonic reflexes
Stabilisation of centre of mass/maintain antigravitational posture
228
Deiter's nucleus receives inhibitory afferentation from...
* Cerebellum
* Cortex
* *Nucl.* *ruber*
229
Give the typical example of supporting reflexes
Cat being dropped whilst upside-down, landing on its feet
230
Give the steps of the cat supporting reflex example
1. Turning back of the head (by _labyrinth-eye-muscle reflex_)
2. Head in the normal position
3. Stimulation of the receptors of the neck
4. Turning of the neck and back
231
Statokinetic reflexes
Positional reflexes evoked by movement stimuli
Accomplished by the integration of the eye, labyrinth and otolith organ
*E.g: 'Gimble' effect of a chicken's head when the body is moved*
232
Placing and hopping reflexes
At the moment of arriving at the ground, extremities always move into the optimal position
* Uses a series of posture reflexes
233
The vestibular nucleus is innervated by...
Pseudounipolar sensory neurons of Scarpa's ganglion
234
The most important efferentations of Scarpa's ganglion
* Oculomotor nuclei
* Cerebellum
* Reticular formation
* Alpha & gamma motor neurons of the spinal cord
235
During intentional movement, which afferents play the main role?
* Those that directly innervate the motor cortex
* Originating from the thalamus and sensory cortex
236
What are the most important movement initiative areas of the brain?
* Limbic system
* Orbital cortex
* Hypothalamus
* System of basal ganglia
237
Brodmann area 6 is known as the...?
Pre-motor area
238
Brodmann area 4 is responsible for...?
Final execution of movement
239
Give the order of processes in the motor cortex
1. Supplementary: Movement intention
2. Pre-motor: Sequence of movements
3. Primary motor: Execution
4. Movement
240
Give the different areas of the motor cortex
* Primary motor cortex
* Brodmann 6:
* Pre-motor area
* Supplementary area
241
Half of the pyramidal tracts originate from the...
Primary motor cortex
242
Pre-motor cortex function
* Determines the sequence of movements following each other
* Investigation nd determination of movement order
243
Motor pathways originate from...
* Pyramidal tract
* Extrapyramidal system
244
Axons from the pyramidal tract leave the neocortex as...
Corticospinal & Bulbospinal tracts
245
Transection of the pyramidal tracts at one side results in...
Paralysis of muscles on the opposite side
246
Informed movements are afferented from the cortex to the...
* Basal ganglia
* Cerebellum
247
Function of the basal ganglia and cerebellum
* Compare the existing movement patterns within a plan
* Send them back to the cortex in a modified form
248
The sensory function of the thalamus continuously provides the cortex with...
Excitatory impulses
249
If the activity of an inner regulatory circuit increases...
The basic inhibitory tone is enhanced significantly
The loop causing this is maintained by an increase in excitatory tone
250
Parkinson's disease is caused by
The substantia nigra contains a vast number of dopaminergic neurons
* These affect the thalamus activating/inhibiting loops
251
The cerebellum is the organ of...
* Movement coordination
* Movement learning
* Attention
* Language
* Accurate timing
252
Give the _main_ functions of the cerebellum
* Correction and refinement of the movement plan
* Learning and storing complex movement plans
253
Give the parts of the cerebellum
1. Archicerebellum
2. Paleocerebellum
3. Neocerebellujm
254
The afferentation of the cerebellum is integrated by...
Purkinje cells
* Although no direct connection to the spinal cord
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Afferents arrive at the cerebellum from which locations?
* Vestibular apparatus
* Collaterals of the visual pathway
256
The main role of the vestibulocerebellum
* Eye movement
* Balance of the body
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Give the **_e_**fferentation of the vestibulocerebellum
1. Alpha + Gamma neurons of spinal cord
2. Nucleus fastigii
3. Then to:
1. Deiters nucleus
2. Reticular formation
3. Nucleus ruber
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Spinocerebellum is composed of...
* Spinocerebellar tracts
* Paleocerebellum
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The main function of the spinocerebellum
Finely adjust the strength of the muscle according to the actual status
260
In the spinocerebellum, the original movement plan is modulated through which loops?
* Thalamus-motor cortex-spinal cord loop
* Nucleus ruber-spinal cord loops
261
Give the afferentations of the cerebrocerebellum
* Brodmann 4
* Brodmann 6
* Gyris postcentralis
262
The afferentations of the cerebrocerebellum switch in the pons allowing...
Comparison of:
* The cortical movement plan
* Cerebellar movement pattern
263
Give the efferentation of the cerebrocerebellum
1. Dentate nucleus
1. Nucleus ruber
2. Thalamus
3. Motor cortex loop
264
Function of the cerebrocerebellum
* Movement planning
* Timing of movements
265
Give the most important cell types in the cerebellar module
* Inhibitory cells
* Facilitating cells
266
Title the figure
The cerebellar module
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Deep cerebellar nuclei
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Purkinje cell
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Function of the basal activity of the Purkinje cell
Inhibition of the firing of deep nuclei
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Releasing deep cerebellar nuclei from Purkinje inhibition can lead to...
Increased main discharge frequency of the afferents originating here
271
Decreasing the activity of the Purkinje cell leads to...
Disinhibition - facilitation of the deep nuclei
272
The main efferentation centre of the cerebellum
Area of cerebellar deep nuclei:
* Nucl. fastigii
* Interpositus nuclei
* Dentate nucleus
273
* Climbing fibre
* Mossy fibre
274
In the cerebellar module, an increase in the activity of granular cells leads to...
Activation of Purkinje cells in parallel with the inhibition of the Purkinje cells of the neighbouring zone
275
Consequences of removal of the cerebellum
Loss of refined coordinated movements
* Ataxia: Poor coordination
* Hypotonia
* Dysmetria
* Tremor
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During sleep, ... predominance is found
Parasympathetic
277
Give the phases of sleep
* SWS (Slow-wave sleep)
* REM/Paradoxical sleep
278
Sleep is measured with which equipment?
Electroencephalography (EEG)
279
REM accounts for ...% of total sleep time
20-25%
280
Which figure shows the sleep cycles
A hypnogram
281
Give the graph showing physiological changes during the phases of sleep
282
Give the EEG waves seen during sleep stages
* Stage 1: Theta waves
* Stage 2: Sleep spindles and K-complexes
* Deep sleep: Delta waves
* REM sleep: Sawtooth waves
283
Title and annotate the figure
Features of an early night sleep cycle
* NREM reaches its greatest depth at stage III and IV
284
Title and annotate the figure
Late-night cycle
* NREM descends only to stage III
285
During sleep, the mean activity of the cortex...
Is not significantly decreased
286
Slow wave sleep is seen in phase numbers...
3 and 4
287
As well as reticular formation, sleep-wake cycles are also determined by the...
Suprachiasmatic nucleus
288
Suprachiasmatic nucleus (SCN) function
* Receives external stimuli by vision
* Biological clock - 24 hour circadian rhythms
289
Circadian rhythms are adjusted by...
Zeitgebers (such as daylight)
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SCN is located in the...
Hypothalamus
291
How is sleep generated?
Serotonin facilitating synchronisation
292
What causes the shift to the REM phase?
Locus coeruleus produces norepinephrine
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The reticular formation is formed by which **_A_**fferents?
* Viscerosomatic sensory system
* Afferent cranial nerves
* Sensory cortex
* Motor cortex
* Thalamus
* Hypothalamus
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The reticular formation is formed by which **_e_**fferents?
* Descending reticular formation (reticulospinal tract)
* Efferents to the upper brain areas
* Thalamus
* Cortex
* Limbic system
* Cerebellum
* Hypothalamus
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Functions of the descending reticular system
* Inhibition of myotatic reflexes
* Increases intensity of the motor processes
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Function of the ascending reticular system
Gears up the activity of all the upper centres
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Title the figure
The norepinephrine system
298
Title the figure
Serotonin (5-HT) system
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Title the figure
Dopamine system
300
Title the figure
The histamine system
301
Title the figure
The cholinergic system
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The limbic system supports which functions?
* _Integration of primitive cortical mechanisms:_
* _Emotional, sexual and visceral function_
* Adrenaline flow
* Emotion
* Behaviour
* Motivation
* Long-term memory
* Olfaction
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The limbic system is divided into...
* Medial limbic ring
* Amygdalic/basolateral limbic ring
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The two main afferents of the limbic system
* Spinothalamic tract
* _Olfactory_ _tract_
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Give the main efferent of the limbic system
Pepez-circuit
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The papez-circuit has efferent fibres to...
* Hypothalamus
* Thalamus + tectal nuclei
* Cingulate gyrus
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Why is the pepez-_circuit_ named as such?
The efferent fibres reach the limbic system _again_
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Mesopallium function
* Stimulation of amygdala - Attacking reaction
* Extirpation of the amygdala - Tame behaviour
* Septal nuclei - Evokes fear
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Archipallium function
* Learning + Control of cortical memory processing
* Emotional reactions
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Give the types of behavioural pattern group
1. Ordinary
2. Signalling
3. Exploratory
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Give the three basic forms of instinctive behaviour
1. Reflexes
2. Taxes - Orientation instincts
3. Modal series of action - Defence, attack, mating
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Instinctive behavioural patterns are evoked by...
Releasers
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Motor response to a stimulus can either be...
Hereditary or acquired
## Footnote
*-Pavlov*
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Unconditioned reflex example
Saliva production when meat is placed in a dogs mouth
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Define an unconditioned reflex
Congenital motor or secretory responses to external stimuli
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Conditional reflex
Neutral stimulus becomes connected to the unconditioned stimulus
* Evoking the same reflex as the unconditioned stimulus
* E.g the bell in Pavlov's experiments
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Positive/negative reinforcement
To build up a conditional reflex of pleasant/unpleasant stimuli
318
If the reinforcement is not caused by the experimenter but by the animal, it is known as...
Operant reflex
319
Increase behaviour
320
* Remove noxious stimuli following correct behaviour
* *Pressing the snooze button on an alarm clock*
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* Behaviour avoids noxious stimulus
* *Studying to avoid a bad grade*
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Decrease behaviour
323
* Add noxious stimuli following behaviour
* *Spanking a child for swearing*
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* Remove appetitive stimulus following a behaviour
* *Telling a child to go to his room for cursing*
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What are the three main stages of memory formation and retrieval?
* Encoding
* Storage
* Retrieval, recall and recollection
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Procedural memory
The memory of performance of an action
* Residing below the level of conscious awareness
327
Declarative memory
Memories that can be consciously recalled, such as facts and knowledge
Divided into:
* Episodic memory
* Semantic memory
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Short-term memory
* Reverberation circuits
* Linked with the frontal lobe and association cortex
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Middle-term memory
* Memory store for hours/days and longer
* Hippocampus, amygdala - Emotions and vegetative functions
* LTP - long-term potentiation
330
Long-term memory
* Not associated with one anatomical structure
* 'Whole association cortex'
* _Engrams:_ Morphological changes caused by repeated stimuli
331
During habituation experimentation with a gastropod's syphon, Ca2+ open as well as...
Ca2+-activated inhibitory K+ channels
332
After repeated touching of the gastropod syphon, a gentle touch on the syphon results in...
Strong retraction of the gill
* Caused by the serotonergic axon terminating the syphon afferent
333
The gill muscle motorneuron is constantly stimulated by...
The syphon afferent
334
NMDA glutamate receptors can only be stimulated by...
* Significant depolarisation
* Transmission of a large amount of glutamate
335
In the hippocampus: A single/less intensive stimulation results in...
The opening of the non-NMDA glutamate receptor
* Therefore only a short-term AP transmission occurs
336
In the hippocampus: A long-lasting stimulation causes...
* Prolonged depolarisation
* Releasing NMDA-linked cation (Na+ and Ca2+)
* Evokes a long-lasting Ca2+ signal
* Generation of retrograde signals
337
