bio of mind Flashcards
(167 cards)
1
Q
what are nerves from the brain called
A
efferent
2
Q
what are nerves that go to the brain called
A
afferent
3
Q
what do excitatory neurones such as glutamate do
A
increase the activity of target cells
4
Q
What do inhibitory neurones such as GABA do
A
decrease the activity of target cells
5
Q
Name the three types of glial cells
A
myelinating glial cells eg schwann cells and oligodendrocytes, supporting glial cells- provide nutrients to cells and help with repair and microglia the immune cells of the CNS
6
Q
what is the somatic nervous system and name the two types of it
A
it is voluntary and it consists of the sympathetic and parasympathetic, sympathetic is the flight or fight and parasympathetic is the housekeeping
7
Q
what does the enteric nervous system do
A
works autonomously to control the activity of the GI tract
8
Q
what does the forebrain consist of
A
cerebrum, thalamus, hypothalamus
9
Q
what gland is the midbrain close to
A
the pituary gland
10
Q
what does the hindbrain consist of
A
pons, medulla oblongata and the cerebellum
11
Q
what does the substantia niagra do
A
motor system, dopamine containing cells recieve visual inputs , helps bring eyes to focus
12
Q
what is periaquaductal grey matter associated with
A
pain and fear
13
Q
what is the red nucleus
A
motor control structure
14
Q
what does the thalamus do
A
important relay nucleus from sensory modalities
15
Q
the frontal lobe is associated with
A
conscious thought
16
Q
what senses does the temporal lobe associate with
A
smell and sound
17
Q
what is the resting membrane potential
A
-70mV
18
Q
what factors contribute to the resting membrane potential
A
charged intracellular proteins, the Na+/K+ pump, potassium and sodium ions
19
Q
what ions is the membrane freely permeable to
A
K+, Na + ions are only slightly permeable
20
Q
what is the equilibrium potential
A
the electrical potential difference that balances an ionic concentration gradient
21
Q
what is the ionic driving force
A
the difference between the real membrane potential and the equilibrium potential
22
Q
what does the Nerst equation calculate
A
the voltage produed by a difference in concentration of a single ion across a membrane
23
Q
what does a stimulus result in
A
results in a small patch of membrane becoming depolarised
24
Q
what is hyperpolarisation
A
current pulses producing passive changes in the membrane potential
25
what happens during depolarisation
current pulses cause passive changes unless threshold is reached once reached action potential occurs
26
what happens in the resting state
all voltage gated channels sodium and potassium channels are closed
27
what happens during the depolarising phase
the na channels are open
28
what happens during the repolarising phase
na channels close and potassium channels open
29
what occurs during undershoot phase
potassium channels remain open and na channels are closed
30
what is the all or nothing rule
action potentials have the same size larger stimuli are encoded by a greater number of action potentials
31
what is refractory period
ensures one way direction of action potentials
32
what are the nodes of ranvier
gaps in the myelin sheath where the voltage gated channels are concentrated causes action potential to jump and is called saltatory conduction
33
what does an intracelular glass electrode do and what is useful for measuring
impales neuron and measures voltage inside cell compared to the outside, its useful for measuring the resting membrane potential
34
what is extracellular recording useful for
measuring action potentials firing
35
what does the voltage clamp amplifier do
compares membrane potential to the desired potential
36
what does current clamp recording do
measures changes in membrane potential
37
what does a patch clamp recording do
are single channel recording measures the current flowing through a single channel
38
what cane xenopus oocytes infected with
exogenous mRNA sequences and they will synthesis the foreign protein in large quantities
39
what are oocytes used for
when families have a gene mutation such as epilepsy
40
what is brain tissue fixed with that fixes proteins
Formaldehyde
41
what is the stain Dapi used for
it is used to detect DNA
42
what is the Nissl stain used to detect
used to detect neurones and glia in the brain
43
what is golgi used to detect
neurones in the brain
44
what is nauta silver stain used to detect
degenerating axons
45
what did electron microscopy reveal
the existence of synapses and ultrastructure of neurones
46
what is immunohistochemistry
is manufacturing antibodies to the candidate protein and visualising these antibodies in sections of the brain
47
what is axoplasmic tranport
is the movement of material down the axon
48
what is anterograde transport
movement of substances from the soma to axon terminal
49
what is retrograde transport
is the movement of substances from the axon terminal to the soma
50
what are gap junctions modulated by
they are modulated by PH, neurotransmitters and Ca 2+
51
give an overview of chemical transmission
amino acid and amine neurotransmitters are synthesised in the axon, peptide neurotransmitters are formed in the cell body, the neurotrnsmitter is taken up into vesicles by transporters, as intracellular calcium levels rise synaptic release occurs, neurotransmitter binds to the receptor molecules in the post synptic membrane, neurotransmitter is either broken down in synaptic cleft or undergoes reuptake into the terminal
52
what are the major neurotransmitters are
amines, amino acids and peptides
53
what is the criteria for a chemical to be considered a neurotransmitter
it must be synthesised in the neurone, it must be present in the presynaptic terminal
54
how are neurotransmitters synthesised
occurs in the cell body using the golgi and Rough ER or in the synaptic terminal using synthesising enzymes transported from the cell body
55
what ions trigger neurotransmitter release
calcium ions
56
what occurs to free vesicles
free vesicles are targeted to the active zones, vesicles dock with the active zone, the docked vesicle is then primed for exocytosis, in response to a rise in Ca ions the vesicles undergo fusion to release their contents, the fused vesicle membrane is taken up into the cell by endocytosis.
57
name the two snare proteins
synaptobrevin is a vesicle bound protein which binds with snap 25 on plasma membrane and synaptotagmin which is a calcium sensor
58
what is a metabotropic receptor
are coupled to intracellular proteins that trnasduce the signal to the cell interior
59
what are ionotropic receptors
they form ion channels that epolarise or hyperpolarise the post synaptic cell
60
what is temporal summation
is when action potentials are fired rapidly down to two postsynaptic
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spacial summation
2 neurones fire action potentials simultaneously
62
is it the excitatory post synaptic potential or the post synaptic action potential that travels down the post synaptic axon
it is the post synaptic action potential which travels down the axon
63
what do electrical synapses do
facilitate communication between neural cells
64
neurotransmitters come in the form of small and large molecules, where are the small and large molecules synthesised
the small molecules are synthesised by enzymes and the large molecules are encoded within the genome
65
what is glutamate
it is the major excitatory neurotransmitter
66
what is Gaba
it is the major inhibitory neurotransmitter, fires chlorine ions
67
give three small molecule neurotransmitters
catecholamines, dopamine and noraepinephrine
68
what is the ionotropic receptor nAchR permeable to
it is permeable to Na+ and K+ and sometimes Ca 2+
69
when is the NMDA receptor only active
during high frequency stimulation
70
what is the structure for metabotropic receptors
made up of monomeric proteins and 7 transmembrane domains
71
what second messenger to metabotropic recpetors act through
G proteins
72
explain the sequence of events that occur when the neurotransmitter binds to a metabotropic receptor
the receptor activates a G protein, the g protein activates the effector protein, the effector protein activates second messenger pathways which lead to metabolic changes in postsynaptic cell these messengers can lead to opening/ closing of ion channels
73
what does the somatosensory system respond to
it responds to the external environment
74
what does the viscerosensory system respond to
it responds to the internal environment
75
what is peripheral innervation
is when the skin and muscle or viscera are innervated by a rich vast network of peripheral nerves
76
what are primary afferents
axons bringing information from the somatic receptors
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what are motor efferents
axons taking information from cns to peripheral structures
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afferents feed into the spinal cord via
spinal nerve and dorsal root
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Efferents leave the spinal cord via the
ventral root and spinal nerve
80
you feel touch by
sensory receptors in the skin
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you detect temperature via
the thermoreceptors in the skin
82
what receptor is associated with pain
the nociceptor
83
what are the three classes of somatosensory receptors
tactile sensations- mechanorecptors, thermal sensations mediated by thermoreceptors and mechanical thermal nociceptors
84
what is meisners copuscle
comprised of lopping axonal terminals supporting cells with low frequency vibrations
85
what is merkels disks
dome structure comprised of axon terminals, merkel cells small forms and shapes
86
what is pacinian corpuscle
sensory axon sorrounded by fluid filled capsule high frequency vibrations
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what is ruffinis corpuscle
nerve terminals intertwined with collagen to do with pressure
88
how is a receptor potential produced
a stimulus deforms the nerve endings and alters membrane permeability producing a receptor potential which triggers and action potential
89
what are large diameter rapidly conducting afferents associated with
low threshold mechanoreceptors
90
what are small diameter slow conducting afferents assoociated with
nocicpetors and thermoreceptors
91
wherabouts is the grey matter on a spinal cord
is in the inside of the spinal cord
92
where is the white matter on a spinal cord
it is on the outside of the spinal cord
93
primary afferents enter the
dorsal root
94
where do nociceptors have their cell bodies
they have their cell bodies in the dorsal root ganglia
95
transduction of painful stimuli occurs in
in the free nerve endings of unmyelinated c fibres and thinly myelinated ad fibres
96
what happens during inflammation
pain afferents send signals to the CNS but also release signalling molecules such as substance P
97
what do pain afferents release
gluatamate
98
what to spinothalamic pathways do
they process afferent inputs from peripheral mechanothermal and polymodal nociceptors
99
what does the contralateral pathway do
the sensory inputs cross at the level of the spinal cord and ascend on the opposite side, information relayed to the thalamus then onto somatosensory cortex
100
what is the macula associated with
central vision
101
what is the forea
central thinner region of the retina
102
what is the optic disc
the orogin of blood vessels where optic nerve axons exit the eye
103
what do photoreceptors do
convert light energy to neural activity
104
cone cells are associated with
colour vision
105
rod cells are
achromatic(without colour) and more sensitive to light
106
what do bipolar cells do
create direct pathway from photoreceptor to ganglic cells
107
the horizontal amacrine cells have
indirect pathways
108
the retinal ganglion cells
axons leave the eye forming the optic nerve
109
what is sound
series of changes in air pressure which form a wave
110
how do we detect sound
the pressure wave comes down external auditory meatus and hits the hypamic membrane
111
what happens at the cochlea
is the point of intergration where the pressure waves are turned into nerve signals
112
what is the scala media
this is where the inner hair cells are situated and are sensory receptors
113
when do we get mechanoelectrical transduction
vibrations causes the organ of corti to move and tectoral membrane distorts the cilia and where the stereocilia are disturbed you get mechanoelectrical transduction
114
what is the endolymph of the scala media high in
it is high in potassium ions and as a result the opening of the channel causes the cell to depolarise, depolarisation results in the opening of voltage gated calcium channels which transmit the signal via neurotransmitter release
115
where is the auditory complex located
it is located on the superior temporal gyrus in the temporal lobe of the brain
116
olfactory epithelial lines the nasal cavity and what happens
odorants enter nasal cavity and dissolve in mucus secretion dissolved odorants bind to cilia
117
where are signals of smell sent
signals are sent to the pyriform cortex in the temporal lobe
118
what happens when odorants bind to cilia
g proteins are activated and produce cAMP and camp binds to ca 2+ and Na+ channels, chloride channels open causing depolarisation
119
what are the organs that contribute to taste
the tongue, pharynx, pallette and epiglottis
120
papilae are taste sensitive structures name the three types of papilae
circurvallate papillae which is the largest and located in posterior, the foliate papilae are elongated and posterior lateral, the fungiform papillae are the smallest and contain one or two taste buds
121
what do dissolved membranes interacting with receptors do
they trigger membrane depolarisation and action potential firing, an increase in intracelular calcium initiates transmitter release and the transmitters excite afferent nerve fibres
122
a circadium rythm must
repeat once a day, persist in the absence of external cues and be able to adjust to local time
123
where is the centre for homeotic circadian control
the superchiasmatic nucleus
124
which cells detect changes in light levels
the retinal ganglion cells have photoreceptors which detect changes in light levels
125
what causes sleep and coma
brain stem lesions
126
what are the stages of sleep
awake, stage 1,2,3,4 then rem sleep - beta theta delta
127
during non Rem sleep
physiological functions decrease
128
which cortices does cognition occur in
the frontal, temporal and parietal lobe
129
Association cortices receive input directly from other cortical areas which areas
Ipsilateral cortico-cortical connections
| Interhemispheric cortico-cortical connections
130
Association cortex also receives highly processed information from primary sensory / motor areas via thalamic nuclei
```
Pulvinar nucleus (parietal association cortex)
Medial dorsal nucleus (frontal association cortex)
[Anterior and ventral anterior nuclei]
```
131
what neurones do Association cortices also receive subcortical inputs
Dopaminergic neurones in the midbrain
Noradrenergic / serotonergic neurones in the reticular formation
Cholinergic neurones in the brainstem and basal forebrain
132
what is attention
The state of selectively processing simultaneous sources of information
133
what is Attention-deficit hyperactivity disorder
| Characterised by
inattention, hyperactivity, impulsiveness
| Imaging suggests that prefrontal cortex and basal ganglia are smaller in sufferers
134
what is Contralateral neglect syndrome
| Caused by
lesion to right parietal cortex
Inability to attend to objects in a portion of space
Failure to attend to stimuli presented to the side of the body (or visual space) opposite the lesion
135
what is Balint’s syndrome
| Caused by
lesion to parietal cortex
Triad of visuospatial deficits:
Simultanagnosia (inability to perceive visual scene as a whole)
Optic ataxia (deficit in visually guided reaching)
Ocular apraxia (difficulty in voluntary scanning of visual scenes)
136
An emotional response consists of three components:
Behavioural E.g. muscular movements (smile, frown etc).
Autonomic E.g. Sympathetic / parasympathetic activity
Hormonal E.g. Adrenaline release
137
what are the Brain systems involved in emotional processing
Amygdala
Orbitofrontal cortex
Cingulate gyrus / thalamus / ventral basal ganglia
138
speech is produced by
Lungs (source of air)
Larynx (source of speech sounds)
Pharynx, oral cavity (incl tongue, teeth, lips) and nasal cavity (modify / filter speech).
139
what are the language Association cortices in left hemisphere
Broca’s area – left frontal cortex; involved in language production.
Wernicke’s area – left temporal cortex; involved in understanding spoken language.
140
what are Aphasias –
damage to specific brain regions which compromises language functions, without affecting sensory / motor processing.
141
Broca’s aphasia
(motor or expressive aphasia)
142
Wernicke’s aphasia
(sensory or receptive aphasia)
143
Conduction aphasia
difficulty repeating words (arise from lesions to pathways connecting language centres)
144
Dorsolateral prefrontal cortex
```
Initiating and shifting behaviour (initiating and changing actions, motor movements and mental plans)
Inhibiting behaviour (suppression of unimportant or distracting information / behaviour)
Simulating behavioural consequences (creation of mental models of the world…abstraction)
```
145
Ventromedial prefrontal cortex
Inhibition of socially inappropriate behaviour (patients with lesions to this area may laugh at inappropriate times or reveal embarrassing personal information)
Sensitivity to the consequences of action (links between stimuli or action and the rewards or punishments that follow)
146
the Motoneurone is teh
(Lower motor neurone)
147
motoneurone is associated with muscle fibers forming a functional entity called
motor unit
148
what is the motor pool
Somatotopic organization of motoneurons in a cross section of the ventral horn at the cervical level of the spinal cord
149
the muscle spindle
Detects changes in muscle length.
Contributes to proprioception i.e. detection of position and movement of body in space.
Enables regulation of muscle contraction and precisely matches force generation to motor task.
150
Extrafusal fibres receive their motor innervation
from alpha motor neurons.
151
The Golgi tendon organ is a .
mechanoreceptor
152
what is a psychiatric disorder of the nervous system
Schizophrenia
153
what are the positive symptoms
Hallucinations
Delusions
Thought disorder
154
what are the negative symptoms
```
Social withdrawal
Flattening of emotional responses
Anhedonia
Disinterest in everyday tasks
Cognitive deficits e.g. Attention, memory
```
155
what are the schizophrenia mechanism
The dopamine turnover hypothesis
Increased DA activity leads to psychosis
DA antagonists or partial agonists antipsychotic
Mesolimbic pathway ↑ – positive symptoms
Mesocortical pathway ↓ – negative symptoms
156
what is bipolar disorder
characterised by mood swings, mania and depression
157
what is depression caused by
Monoamine theory
| Caused by decreased function of 5-HT and NA systems
158
what are depression treatments
```
Monoamine uptake inhibition
Tricyclic antidepressants (e.g. imipramine)
SSRIs (e.g. fluoxetine)
SNRIs (e.g. venlaflaxine)
NRIs (e.g. bupropion)
```
Monoamine receptor antagonists
Non-selective blockers of especially α2 and 5-HT2
E.g. trazodone
Monoamine oxidase inhibitors
Irreversible, non-competitive, non-selective for MOA-A/B (e.g. phenelzine)
Reversible, MAO-A selective (e.g. moclobemide
159
what is a treatment for anxiety disorders
Treatment
Benzodiazepines, barbiturates
SSRIs/SNRIs
Buspirone
Affect GABA/5HT systems
160
what parts of the brain are affected by alzheimers
Hippocampus: impaired short term memory
| Note the widened sulci and narrowed gyri with Alzheimer’s.
161
what pathways in alzheimers are affected
Cholinergic pathways particularly affected
162
what are the alzheimer treatment
Increases ACh levels
May slow progression
May improve cognition
163
what are the symptoms of multiple sclerosis
```
Sensory changes
Muscle weakness
Coordination and balance
Speech
Swallowing
Visual
Fatigue,
Pain
Incontinence
Cognitive impairment
Depression
Mood swings
```
164
what are the causes of MS
Autoimmune
Oligodendrocytes affected
Myelin sheath degrades
Most common in women
165
what happens during substancia niagra
diminished substancia niagra seen
166
what is Huntington's Disease
Inherited disorder
Autosomal dominant
Polyglutamine repeat
Huntingtin
167
what is the pathology of huntingtons disease
Loss of neurones cerebral cortex corpus striatum
GABAergic
Cholinergic
