Neuurology MedEd BRS tutorial Flashcards
1
Q
What are the 3 parts the brain is split into?
A
forebrain
midbrain
hindbrain
2
Q
What does the forebrain made up of?
A
cerebral hemispheres
diencephalon
3
Q
What is the hindbrain made up of?
A
pons
medulla
cerebellum
4
Q
What is the brainstem made up of?
A
midbrain + pons + medulla
5
Q
What are the 4 lobes of the brain?
A
frontal
parietal
temporal
occipital
6
Q
What is the function of frontal lobe?
A
motor function
language
planning
memory
7
Q
What is the function of parietal lobe?
A
sensation (touch n pain)
sensory parts of language
spatial orientation
8
Q
What is the function of temporal lobe?
A
auditory info
9
Q
What is the function of occiptial lobe?
A
visual info
10
Q
What is the function of limbic lobe?
A
learning
memory
emotion
motivation
11
Q
What is the limbic lobe made up of?
A
amygdala
hippocampus
mamillary body
cingulate gyrus
12
Q
What is the function of insular cortex?
A
visceral sensation
autonomic control
interoception (sensation from within body)
balance
13
Q
Where is insular cortex located?
A
deep within lateral fissure
14
Q
What is the dividing line between frontal and parietal lobes?
A
central sulcus
15
Q
What are the 3 layers of the meninges?
A
dura
arachnoid
pia
16
Q
What is the dura made up of?
A
2 layers
1) periosteal
2) meningeal (durable, dense, fibrous)
17
Q
What is the arachnoid?
A
thin transparent spider-like projections
18
Q
What is the pia?
A
innermost layer
thin translucent mesh-like
tight to surface of brain
19
Q
How are the lateral (1st and 2nd ventricles) connected to the 3rd ventricle?
A
interventricular foramen
20
Q
How is the 3rd ventricle connected to the 4th ventricle?
A
cerebral aqueduct
21
Q
How is the 4th ventricle connected to spinal canal?
A
central canal
22
Q
What is the fluid inside the ventricles?
A
cerebrospinal fluid
23
Q
Where is CSF made?
A
choroid plexus (lateral, 3rd, 4th ventricles)
24
Q
Where is CSF found?
A
ventricular system
sub-arachnoid space
25
What is the CSF reabsorbed by?
arachnoid villi
then goes into superior sagittal sinus (space in midline of brain)
26
CSF vs plasma
CSF has...
lower pH
less glucose, protein, K+
same Na+
27
What is hydrocephalus? And where is it most likely to happen?
blockage of CSF which causes a build-up of fluid in brain
cerebral aqueduct (bottleneck in system)
28
Where is the primary motor cortex located?
pre-central gyrus
29
Where is the primary somatosensory cortex located?
post-central gyrus
30
What is the spinal cord made up of?
white matter surrounding grey matter
31
What does the grey matter form?
ventral and dorsal horns
32
What is the mixed spinal nerve formed from?
dorsal root + ventral root
have both sensory and motor axons
33
What is the dorsal root ganglion?
enlargement in dorsal root containing cell bodies of all primary sensory neurons
34
How many pairs of spinal nerves do we have?
31
35
How many of each spinal nerves do we have?
C8
T12
L5
S5
Co1
36
Where do C1-C7 emerge from?
via intervertebral foramina
above vertebrae
37
Where do C8 onwards emerge from?
below vertebrae
38
How many cervical vertebrae are there? How many cervical nerves?
7 cervical vertebrae
8 cervical nerves
39
What are spinal enlargements?
widened areas of the spinal cord supplying the limbs
40
What does the cervical enlargement supply?
arms
41
What does the lumbar enlargement supply?
legs
42
What are the 2 descending pathways?
corticospinal tract (major descending pathway)
corticobulbar tract
43
What does 85% of the fibres descussating in the medulla mean?
left side of brain causes movement of right side and vice versa
44
Where are the UMNs and LMNs in corticospinal tract located?
UMNs - primary motor cortex
LMNs - brainsteam (head and neck) and spinal cord (body)
45
What does the corticobulbular tract control?
muscles of eye, face, tongue and chewing
46
What are the 2 ascending pathways?
dorsal column
spinothalamic tract
47
What is the dorsal column responsible for?
fine touch
vibration
proprioception
48
How do the fibres in the dorsal column enter the spinal cord?
via dorsal horns
49
Through which tract does info from lower body (below T6) travel through?
gracile tract
50
Through which tract does info from upper body travel through?
cuneate tract
51
Where do the neurones synapse in the dorsal column?
synapse in medulla
decussate
synapse in thalamus
3rd order neurones then go to somatosensory cortex
52
What 2 parts is the spinothalamic tract split into?
lateral spinothalamic tract
anterior spinothalamic tract
53
What is the lateral spinothalamic tract responsible for?
pain
temp
54
What is the anterior spinothalamic tract responsible for?
crude touch (heavy touch)
55
Where do the neurones synapse in the spinothalamic tract?
synapse in spinal cord
decussate
synpase in thalamus
3rd order neurones then go to somatosensory cortex
56
What are extrapyramidal tracts?
tracts that supply the brainstem
57
What are the 4 extrapyramidal tracts?
vestibulospinal tract
tectospinal tract
reticulospinal tract
rubrospinal tract
58
What is the function of vestibulospinal tract?
head movement
59
What is the function of the tectospinal tract?
head orientation during eye movement
60
What is the function of the reticulospinal tract?
breathing and emotional motor function
61
What is the function of the rubrospinal tract?
innvervates lower motor neurons of upper limb
BUT taken over by the corticospinal tract
62
What does contralateral mean?
opposite sides
63
What does ipsilateral mean?
same side
64
What is Brown Sequard syndrome caused by?
hemisection of the spinal cord
65
What are the symptoms of Brown Sequard syndrome? And which pathway causes these symptoms?
ipsilateral weakness/paralysis
lateral corticospinal tract
ipsilateral loss of proprioception
dorsal column
contralateral loss of pain and temperature
lateral spinothalamic tract
66
Causes of Brown Sequard syndrome?
trauma (spinal fracture, fall, stabbing, gunshot)
spinal tumour
MS
ischaemia/infarction (due to interrupted blood supply)
67
What is stroke caused by?
interrupted blood supply to the brain
68
What is FAST?
Face - drooping and paralysis
Arms - unilateral weakness/numbness
Speech - slurred, unable to speak/understand
Time to dial 999
69
A 75-year-old patient has a stroke, immediate signs were moderate weakness and loss of sensation in left hand and forearm. Where was the stroke?
right parietal lobe
in/near somatosensory cortex
70
What are stroke complications?
can lead to tissue damage in brain
can lead to an epileptic focus
71
What are symptoms of stroke?
involuntary jerking
seizures
werid sensations
visual/auditory symptoms
72
WHich tracts do NOT cross over?
anterior corticospinal tract
corticobulbar tract
73
Where do the affrent nerves convey info from?
skin
skeletal muscles
joints
74
Where do efferent nerves convery information TO?
skeletal muscles
75
What is a dermatome?
area of skin innverated by a single spinal nerve
BUT NO C1
76
What is a myotome?
group of muscles innverated by a single spinal nerve
77
Where do all afferent fibres in the PNS synapse?
spinal ganglia
78
Where do visceral efferent fibres synapse?
peripheral ganglia
79
How are peripheral nerves arranged?
in fasciculi
80
What are the 3 layers of the connective tissue?
epineurium - external vascular layer
perineurium - covers fasciculus
endoneurium - covers individual axons
81
What are the 2 ways in which peripheral nerves can be classified?
conduction velocity
axonal diameter (sensory neurones ONLY)
82
What type of receptors detect external sources of stimulus?
exteroceptors (detects pain, temp, touch, pressure)
83
What type of receptors detect internal sources of stimulus?
proprioceptors (movement, joint position)
enteroceptors (movement through gut, blood pH)
84
What are the 3 types of proprioceptors?
muscle spindles - detect changes in muscle length
golgi tendon organs - detects changes in tension in tendons
joint receptors - detect start and end of movement
85
What is the NMJ?
specialised synapse between motor neuron and muscle fibre
86
What elicits involuntary coordinated pattern of muscle contraction and relaxation?
peripheral stimuli
87
What do nociceptors detect?
pain
88
Where do visceral sensory neurons relay info from?
from core
89
Where do visceral motor neurones relay info to?
outflow to core and body wall
90
What do visceral sensory neurons control?
pain
fullness
bp
91
What do visceral motor neurons control?
pupils
sweat glands
salivary glands
heart muscle
airways
92
What spinal and cranial nerves are involved in visceral sensory neurons?
T1-L2
S2-S4
CN IX and X
93
What spinal and cranial nerves are involved in visceral motor neurons?
thoracolumbar T1-L2
craniosacral CN III, VII, IX, X
94
What happens when there is injury to dorsal root?
loss of sensation in the dermatome supplied by spinal nerve
95
What happens when there is injury to the ventral root?
weakness in corresponding myotome
96
What is radiculopathy?
nerve root pain due to compressed spinal nerve
eg. sciatica
97
What are the symptoms of radioculopathy?
weakness/stabbing/burning/shooting pain
worse on movement
pins and needles (parasthesia)
98
What are the causes of radiculopathy?
herniated disc
foraminal stenosis (narrowing)
spondyloisthesis (veterbral slippage)
malignancy
arthritis
bone growths
99
What are investigations for radioculopathy?
straight leg raise test
imaging
100
What is the treatment for radiculopathy?
analgesia (NSAIDs)
exercise and stretching
epidural injections
decompression surgery/disectomy
101
What happens when bp decreases?
baroreceptors fire less often
less signal through visceral motor neuros
parasympathetic effect decreases
sympathetic system ISN'T inhibited
bp increases
baroreceptor firing is proportional to bp
102
What is the location of the sympathetic ganglions?
close to spinal cord
103
What is the location of the parasympathetic ganglions?
close to/embedded within effector tissue
104
What is the sympathetic pre-ganglionic fiber length?
Sympathetic
Short
SS
parasympathetic opposite = long
105
What is the sympathetic post-ganglionic fiber length?
long
106
What is special about adrenal innervation?
sympathetic innervation only
no ganglion
SINGLE nerve (resembling pre-ganglionic straight to adrenal gland)
107
Does the sympathetic or parasympathetic system have more control and why?
sympathetic
sympathetic ganglions exist as long chains that run parallel to the spinal chord
sympathetic nerves emerging from spinal chord synapse the sympathetic trunks
ALL ganglions connected = whole trunk activated = mass activation
coordinated fight/flight response
108
What is special about lung innervation?
direct parasympathetic innvervation
no direct sympathetic innervation
lung bronchodilates via adrenaline from adrenal gland
109
What are the steps of the micturition reflex?
1) pressure increases in bladder
2) SNS keeps internal sphincter contracted
3) pressure continues to rise (as u drink more water)
4) parasympathetic innervation dominates
5) detrusor muscle contracts
6) urine leaves bladder
somatic motor neurons give voluntary controls
110
What do ion channel receptors mediate?
all fast excitatory and inhibitory transmission
FAST response
111
What type of receptor are nicotinic ACh receptors?
ion channel receptors
112
Where are nicotinic ACh receptors found?
all ANS ganglion
adrenal medulla
113
What kind of response comes from G coupled protein receptors?
slow response
effectors may be enzymes or channels
114
What type of receptors are G protein coupled receptors?
muscarinic receptors
adrenergic receptors
115
Where are muscarinic receptors found and what are they for?
between PARASYMPATHETIC post ganglionic fibre and effector tissue
for ACh
116
Where are adrenergic receptors found and what are they for?
between SYMPATHETIC post ganglionic fibre and effector tissue
noradrenaline
117
What is the general mechanism for neurotransmission? (6)
1) precursor enzymatically converted to neurotransmitter
2) packaged into vesicles
3) action potential causes Ca2+ influx and exocytosis
4) exocytosis and neurotransmitter release
5) receptor activation
6) removal of neurotransmitter from synapse via uptake into pre-synaptic terminal/glial cell
118
What enzyme converts DOPA to dopamine?
DOPA decarboxylase
119
How is dopamine (neurotransmitter) removed from synapse? (2 ways 2 enzymes)
monoamine oxidase in presynaptic terminal
COMT (catechol-O-methyltransferase) in glial cells
