Nervous system overview II Flashcards
1
Q
hindbrain: consists of
A
- pons
- cerebellum
- medulla oblongata
2
Q
metencephalon: general features
A
- aka cerebellum
- 10% of volume of entire brain
- 80% of neurons in brain
- ‘silent area’ direct electrical stimulation causes no sensation and few motor outputs
3
Q
metencephalon: function
A
- controls balance and posture (from inputs from vestibular system, proprioceptors)
- coordinates timing and force of muscles groups during voluntary movements
- ‘guidance system’ error detector to continuous refine motor output during task
- helps in motor learning
- controls eye movements: part of verstibulooocular reflex (VOR)
4
Q
eg. lack of cerebellum
A
- 9 cases recorded, most patients die young
- CT scan showed lack of cerebellum
- dizziness, nausea, moderate motor impairment (walking) and mild speech problems (delayed speech development)
- cerebellar functions may have been taken over by cortex
5
Q
brainstem: name areas
A
- medulla oblongata
- pons
- midbrain
6
Q
brainstem: function
A
controls numerous essential functions:
- heart rate
- breathing
- sleeping
- eating
- consciousness/ alertness
7
Q
brainstem: primary motor/ sensory innervation of face and neck
A
- via cranial nerves
- 10 arise from the brainstem
8
Q
metencephalon: function
A
- aka pons
- relays signals from forebrain to cerebellum
- nuclei for efferent fibres CN V - VIII
9
Q
metencephalon: nuclei deal primarily with
A
- sleep, bladder control respiration
- hearing, equilibrium, posture, eye movements
- taste, swallowing, fascial expressions, facial sensation
10
Q
metencephalon: pontine respiratory centres and name centres
A
- essential for regulation of respiration
- modulate respiratory nuclei in medulla
- pneumotaxic centre
- apneustic centre
11
Q
metencephalon: pneumotaxic centre
A
- controls rate of breathing through rhythmic bursts of activity
12
Q
metencephalon: apneustic centre
A
- controls depth of breathing
- works w pneumotaxic centre to ensure ventilation is smooth and coordinated
13
Q
myelencephalon: general function
A
- aka medulla oblongata
- controls many autonomic functions essential for life
- eg. cardiovascular and respiratory systems
- rhythmic cycle of breathing originates in medulla
14
Q
myelencephalon: breathing- chemoreceptors
A
- medulla
- monitor blood pressure, CO2, pH
15
Q
myelencephalon: breathing- dorsal respiratory group (DRG)
A
- medulla
- inhalation
- control rhythm of breathing (pacemaker cells)
- send impulses to motor nerves innervating diaphragm and intercostal mm
16
Q
myelencephalon: breathing- ventral respiratory group (VRG)
A
- medulla
- inhalation and exhalation
- sends impulses to motor nerves innervating throat, diaphragm, intercostal and ab mm
17
Q
myelencephalon: breathing- DRG/ VRG activity modified by
A
- medulla
respiratory centres in the pons
18
Q
myelencephalon: nuclei for
A
- medulla
- efferent fibres CN VIII - XII
19
Q
myelencephalon: assists in control of muscle tone, balance, posture
A
- medulla
- vestibula nuclei (rostral medualla) - caudal pons
- receive inputs regarding balance and spatial orientation from cerebellum and vestibular apparatus in inner ear (via CN VIII)
- sends signals to motor neurons controlling leg mm, and muscles of head, eyes, neck, trunk, proximal limbs
20
Q
mesencephalon: tectum features
A
- midbrain
- superior colliculi
- inferior colliculi
21
Q
mesencephalon: tectum superior colliculi (SC)
A
- receive visual input from thalamus (lateral geniculate nucleus)
- coordinates eye movements
- orientation of eyes and head
22
Q
mesencephalon: tectum inferior colliculi (IC)
A
- receive auditory input from thalamus (medial geniculate nucleus)
- auditory signal integration
- frequency recognition
- pitch discrimination
23
Q
SC + IC =
A
corpora quadrigemina
24
Q
mesencephalon: tegmentum name parts
A
- midbrain tegmentum
- pontine tegmentum
- medullary tegmentum
25
mesencephalon: tegmentum- midbrain tegmentum general features
- red nucleus
- substantia nigra
- ventral tegmental area
- periaqueductal grey matter
- nuclei of CN III and IV
26
mesencephalon: tegmentum- midbrain tegmentum red nucleus
- motor coordination of shoulders/ upper arms
27
mesencephalon: tegmentum- midbrain tegmentum substantia nigra
- movement planning
- eye movements
- reward seeking
- addiction
28
mesencephalon: tegmentum- midbrain tegmentum ventral tegmental area
- dopaminergic neurons
- reward
- pleasure
29
mesencephalon: tegmentum- midbrain tegmentum periaqueductal grey matter
- controls basic movement sequences involved in fighting, mating, descending pain modulation
30
mesencephalon: tegmentum- pontine tegmentum
nuclei of CN V to VIII
31
mesencephalon: tegmentum- medullary tegmentum
nuclei of CN IX, X, XII
32
mesencephalon: tegmentum- what is the reticular formation
- network of 'reticular nuclei' on each side of tegmentum (midbrain, pons, medulla)
- part of reticular activating system (RAS) or ascending around system
- critical for maintaining 'alert wakefulness; and controlling sleep-wake transitions
- helps to promotes cortical 'alertness' and direct attention to specific events
33
mesencephalon: tegmentum- reticular formation receives input from
- cerebral cortex, cerebellum, vestibular nuclei, ascending (sensory) fibres of spinal cord
34
mesencephalon: tegmentum- reticular formation projects to and importance
- thalamus
- hypothalamus (diencephalon)
- telencephalon
- making areas more receptive to signals comings from other pathways
35
cranial nerves: features
- 12 cranial nerves (CN) give sensory and motor function to head and neck
- some involved in autonomic control (eg. vagus CN X)
- 10 arise from nuclei in midbrain and hindbrain (pons and medulla)
36
cranial nerves: mnemonic
oh oh oh, to touch and feel very good velvet, ah heaven
37
diencephalon: name main structures
- thalamus
- hypothalamus
- epithalamus
38
diencephalon: function
- integrates sensory info and motor commands
| - regulates autonomic functions, emotions
39
thalamus: features
- midline, symmetrical structure
| - comprises multiple nuclei
40
thalamus: function
- relays all sensory (afferent) input to cortex (exc olfaction)
- regulate consciousness, sleep, alertness
- relays info from cerebellum and basal ganglia -> motor cortex to coordinate movement
41
thalamic nuclei: name 3 groups
- relay nuclei
- association nuclei
- 'nonspecific' nuclei
42
thalamic nuclei: relay nuclei function
```
process signals coming from:
- periphery (sensory afferents),
- basal ganglia,
- cerebellum (motor pathways)
and relays to cortex
```
43
thalamic nuclei: relay nuclei eg
relay: ventral nuclei, medial/ lateral geniculate nuclei
44
thalamic nuclei: association nuclei
connect areas of cortex w each other
- eg. control eye movements and attending to visual stimuli
- connect limbic areas involved in emotions and autonomic regulation
45
thalamic nuclei: association nuclei eg.
association: pulvinar, dorsal nuclei
46
thalamic nuclei: nonspecific nuclei
receive input from other thalamic nuclei, cortex and brainstem
- influence arousal, alertness and sleep (ARAS)
47
thalamic nuclei: nonspecific nuclei eg.
nonspecific: reticular nucleus
48
hypothalamus: function
- responds to int/ext environmental changes detected by somatic sensory/ visceral sensory fibres
- important component of limbic system (esp generating visceral response to emotional stimuli)
49
hypothalamus: regulates
numerous autonomic functions and this critical for maintaining homeostasis
50
hypothalamus: provides link btw
nervous and endocrine systems (pituitary gland)
| - regulates endocrine system
51
hypothalamus: how many nuclei
11 pairs
52
epithalamus: consists of
- habenula
- stria medullaris
- pineal gland
53
epithalamus: habenula
- implicated in anxiety,
- stress,
- pain,
- avoidance learning,
- attention,
- negative reward signals (inhibits dopaminergic neurons)
- psychosis
54
epithalamus: stria medullaris
- fibre bundle that connects hypothalamus to habenula
55
epithalamus: pineal gland
- small endocrine gland that secretes melatonin
| - essential for maintaining regular sleep-wake cycles (ie. circadian rhythms)
56
cerebrum: general features
2 cerebral hemispheres consisting of:
- cerebral cortex
- subcortical (deep) structures
- white matter tracts
57
cerebrum: name 3 types of subcortical (deep) structures
- limbic structures
- basal ganglia
- olfactory bulb
58
cerebrum: list limbic structures
- hippocampus
| - amygdala
59
cerebrum: list basal ganglia
- caudate
- putamen
- globus pallidus
60
list main central lobes of cerebrum:
- frontal lobe
- parietal lobe
- occipital lobe
- temporal lobe
61
limbic lobe: features
- arc-shaped region of cortex on medial surface of each hemisphere
- collection of limbic structures in forebrain and midbrain
62
limbic lobe: function
- emotion
- behaviour
- motivation (reward)
- memory
- olfaction (via olfactory bulb)
63
what are basal nuclei:
large masses of grey matter deep within cerebral hemispheres
64
basal nuclei: function
- subcortical nuclei that communicate w areas of cortex, thalamus, brainstem
65
basal nuclei: forms circuits
- form circuits that influence emotions, motivation, memory, cognition and motor function
66
basal nuclei: consists of
- caudate
- putamen
- globus pallidus
67
basal nuclei: caudate function
- learning, storing/processing memories, language comprehension
- motor coordination
- emotions (love?), OCD
68
basal nuclei: putamen function
- works w caudate and globus pallidus to coordinate limb movements
- implicated in perception of hate, contempt, disgust
69
basal nuclei: globus pallidus (GP) function
regulation of movement: inhibitory action that balances excitatory action of cerebellum
- connected to other basal nucleus (subthalamic nucleus- STN)
- GP and STN work together to create pacemaker circuits that control rhythmic activities involved in motor function
70
GP and STN targets for:
deep brain stimulation therapy
| - for treating Parkinson's disease, reduces muscle tremors
71
what is limbic system:
collection of structures from forebrain (telencephalon, diencephalon) and midbrain (mesencephalon)
72
limbic system: responsible for
- learning/ long term memory
- processing of emotions
- behaviour, mood, motivation
73
limbic system: telencephalic structures include
- hippocampus
- amygdala
- cingulate gyrus
- parahippocampus gyrus
74
limbic system: diencephalic structures include
- thalamus
| - hypothalamus
75
limbic system: hippocampus function
essential for learning, memory, navigation (spatial awareness)
76
limbic system: amygdala function
formation/ storage of memories associated w emotional events (rage, fear, anxiety)
77
limbic system: cingulate gyrus function
- emotion
| - memory
78
limbic system: parahippocampus gyrus function
- memory encoding and retrieval
79
limbic system: thalamus function
processes and relays sensory info
80
limbic system: hypothalamus function
visceral responses to emotional stimuli (sexual, anger, aggression)
81
telencephalon- white matter: consists of
neuronal fibres (axons)
82
telencephalon- white matter: classified into 3 groups
- commissural fibres
- association fibres
- projection fibres
83
telencephalon- white matter: commissural fibres
make connections btw L and R hemispheres
84
telencephalon- white matter: association fibres
interconnect areas of cortex within SAME hemisphere
85
telencephalon- white matter: projection fibres
travel to and from cortex
86
telencephalon- white matter: commissural fibres eg.
corpus callosum
87
corpus callosum:
- largest fibre bundle/ tract in human brain
| - transfers motor, sensory, cognitive info btw hemispheres
88
telencephalon- white matter: association fibres types
- arcuate fibres
| - longitudinal fasciculi
89
telencephalon- white matter: arcuate fibres
short association fibres that connect adjacent cortical gyri
90
telencephalon- white matter: longitudinal fasciculi
longer association fibres that connect frontal lobe to other lobes
91
telencephalon- white matter: longitudinal fasciculi eg.
- ext capsule: numerous cortico-cortical association fibres
- extreme capsule: interconnects areas of cortex involved in speech production (Broca's area) and language understanding (Wernicke's area)
92
telencephalon- white matter: projection fibres types and eg.
- ascending (afferent) fibres
| - descending (efferent) fibres (eg. axons of cortical pyramidal cells)
93
telencephalon- white matter: where do these projection fibres come from
- all parts of cortex in corona radiata
| - converge into compact bundle (tract) called internal capsule
94
cerebral cortex: gross anatomy features
- outermost portion of brain
highly convoluted:
- sulci (grooves)
- gyri (ridges)
95
cerebral cortex: neuroanatomy features
- thin layer of grey matter
- neurons organised into functional units (cortical columns)
- each column segregated into layers (laminae)
96
cerebral cortex: cortical columns specialised
to process specific inputs or outputs
97
cerebral cortex: name 3 divisions based on histological appearance
- neocortex
- paleocortex
- archicortex
98
cerebral cortex: neocortex
- most of cortex
| - 6 layers
99
cerebral cortex: paleocortex
- olfactory bulb
| - 3 layers
100
cerebral cortex: archicortex
- hippocampus
| - 3-4 layers
101
cerebral cortex: 2 main types of neurons
- pyramidal
| - stellate (granular)
102
cerebral cortex: pyramidal neurons
- layers III and V
- large dendritic trees: contact many other neurons
- axons project out of cortex into other regions of brain and spinal cord= main output cells of cortex (projection neurons)
103
cerebral cortex: stellate (granular) neurons
- layers II and IV
- shorter axons and dendritic trees that remain within cortex
- main interneurons of cortex (association neurons)
104
cerebral cortex: how many distinct cortical areas based on distribution of cells in each layer
52 cortical areas
105
cerebral cortex: cells in primary motor cortex
- large no. pyramidal neurons that project into brainstem and spinal cord (corticospinal tract)
- relatively few stellate neurons
106
cerebral cortex: cells in primary somatosensory cortex
- many stellate neurons that process sensory info
| - relatively few pyramidal neurons
107
morphological/ functional complexity of pyramidal cells increase from: and thus
- post to ant brain regions = increase in complexity of info processing occurring in those regions
108
cerebral cortex: general functions
- cortex subdivided into areas specialised for specific functions
- each cerebral hemisphere concerned w sensory and motor functions of OPPOSITE side of body
109
cerebral cortex: lateralisation
some functions present predominantly in one cerebral hemisphere
110
cerebral cortex: name primary cortices
- primary sensory cortex
| - primary motor cortex
111
cerebral cortex: primary sensory cortex and eg.
- processes low level sensory info
| - eg. primary visual cortex
112
cerebral cortex: primary motor cortex
main source of outputs to somatic motor systems
113
cerebral cortex: association cortices function
- distributed neural networks that combine info and commands from different cortical and subcortical areas
- performs higher order (more complex) analytical functions and produce meaningful perceptual experience
- largely responsible for cognitive processes that occur btw receipt of sensory info and generation of behaviours
114
cerebral cortex: association cortices name 2 types
- unimodal
| - poly/multimodal
115
cerebral cortex: unimodal association cortices
- deals w info primarily from one sensory system/ or primary sensory cortex
116
cerebral cortex: polymodal association cortices
- receives different types of sensory input as well as input from other brain areas including cortex, diencephalon, brainstem
117
cerebral cortex: unimodal eg.
- visual association area
- somatosensory association area
- motor association area
118
cerebral cortex: polymodal eg.
prefrontal cortex
119
cerebral cortex: visual association area function
- aka occipital lobe
| - responds to specific objects (eg. shapes, faces)
120
cerebral cortex: somatosensory association area function
- aka parietal lobe
| - uses somatic sensory input received by somatic cortex to interpret size, form, texture
121
cerebral cortex: motor association area function
- aka promotor cortex; frontal lobe
| - plans and coordinate movement involving different mm groups
122
cerebral cortex: prefrontal cortex
- aka front lobe
- enables you to predict consequences of different behaviours, plan future behaviours and perform abstract thought; seat of personality
