CNS Flashcards
1
Q
Major divisions of nervous system
A
Central nervous system
peripheral nervous system
2
Q
CNS
A
brain + spinal cord
3
Q
PNS
A
nerves that connect CNS to peripheral structures
4
Q
neurons
A
functional unit of nervous system
generates electrical signals = action potentials
5
Q
glial cells
A
non neuronal cells that support neurons
protective
6
Q
afferent neurons
A
takes info from periphery to CNS
terminals contain sensory receptors
cell body is in PNS - peripheral axon connects terminals to cell body; central axon synapses with interneuron in CNS
7
Q
interneurons
A
lie entirely within CNS
> 99% of all neurons
8
Q
efferent neuron
A
most of the axon is in the PNS
cell body is in the CNS; receives signal from interneuron
long axon → length of axon = speed of response
9
Q
astrocytes
A
glial cells; star shaped
provide neurons with nutrients → connect blood + neuron
formation of BBB
10
Q
oligodendrocytes
A
glial cells
make myelin in CNS
11
Q
ependymal cells
A
glial cells
make CSF
12
Q
microglia
A
glial cells
‘immune cells’ of CNS → support + protection
13
Q
Schwann cells
A
make myelin in PNS
14
Q
lobes of the brain
A
have corresponding bones that form the skull
15
Q
central sulcus
A
separates frontal and parietal lobes
16
Q
lateral sulcus
A
separates temporal lobe from frontal and parietal lobes
17
Q
planes
A
coronal = front and back
horizontal = top and bottom
sagittal = hemispheres
18
Q
anterior
A
in front of
19
Q
posterior
A
behind
20
Q
superior
A
above
21
Q
inferior
A
below
22
Q
dorsal
A
top (of longitudinal axis of forebrain)
back (of longitudinal axis of brainstem + spinal cord)
23
Q
ventral
A
bottom (of longitudinal axis of forebrain)
front (of longitudinal axis of brainstem + spinal cord)
24
Q
forebrain
A
cerebrum (all lobes)
diencephalon
25
midbrain
eye movement
part of brainstem
26
hindbrain
cerebellum
pons
medulla oblongata (brainstem)
27
diencephalon
thalamus
pineal gland
hypothalamus
pituitary gland
28
thalamus
integrating center and relay station for sensory and motor information
29
pineal gland
melatonin secretion in response to darkness = sleep
30
hypothalamus
homeostasis
behavioural drive
temperature control, water balance, eating + drinking, emotional behaviour
regulates reproductive system and circadian rhythms
31
pituitary gland
hormone secretion
'master' gland
32
brainstem
midbrain
pons
medulla oblongata
reticular formation
33
pons
relay station between cerebrum and cerebellum
coordination of breathing
34
medulla oblongata
control of involuntary functions
ex. breathing, blood pressure
35
reticular formation
arousal
sleep/wake cycle
muscle tone
pain modulation
locomotor initiating centre
36
cerebrum
outer shell of grey matter = cell bodies
(grey matter contains pyramidal cells)
inner layer of white matter = myelinated axon tracts
37
ventricles
make CSF
contact with subarachnoid space
38
limbic system
septum, cingulate gyrus, amygdala, hippocampus, olfactory bulbs
surrounds thalamus + hypothalamus
associated with learning/memory, emotion, visceral function (appetite), sex, endocrine function
39
cingulate gyrus
emotions
pain modulation
40
septum
contains septal nuclei
connect limbic structures to cortical areas
41
olfactory bulbs
smell
can be associated with memories + emotions
42
hippocampus
memory
learning
43
amygdala
emotions → anxiety + fear
44
cerebral cortex
participates in perception, generation of skilled movements, and cognitive functions → reasoning, learning, and memory
45
basal ganglia
initiation of movement and coordination of skeletal muscle activity
46
cerebellum
coordinates movements → eye movement; posture and balance
some forms of learning
47
spinal cord
locomotor pattern generator → produces rhythmic movements
spinal reflexes
48
protective elements of CNS
bone → skull, vertebrae
meninges: dura mater, arachnoid mater, pia mater
cerebrospinal fluid
Blood brain barrier
49
cerebrospinal fluid
cushions structures in subarachnoid space
50
blood brain barrier
'chemical' protection
helps maintain a stable environment for the brain
controls rates + substances that enter extracellular fluid of brain
endothelial cells form tight junctions around blood vessels
sealed by astrocytic end-feet
51
meninges
brain → pia mater → subarachnoid space → arachnoid mater → venous blood → dura mater → skull
52
spinal nerves
31:
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
extend from spinal cord; correspond to regions of the spinal cord
53
dermatome
area of skin innervated by corresponding spinal nerve
54
myotome
set of muscles innervated by corresponding spinal nerve
55
cervical
head, neck, shoulders, arm, hand
56
thoracic
trunk
57
lumbar
waist, front of legs, feet
58
sacral
buttocks, genitals, back of legs, feet
59
coccygeal
tail bone
60
roles of spinal cord
send sensory info to brain
send motor commands to periphery
coordinate reflexes
contains central pattern generators
61
dorsal root
carries afferent info to CNS
afferent neuron axons enter spinal cord from peripheral nerves via dorsal root
62
ventral root
carries efferent info to muscles + glands
axons of efferent neurons leave spinal cord via ventral root
63
reflexes
motor response without signals from brain
64
central pattern generators
control rhythmic movements
65
dorsal root ganglia
contain cell bodies of afferent neurons entering dorsal root
66
spinal cord matter
opposite from brain
grey matter is inside
white matter is outside
67
grey matter in spinal cord
dorsal horn: sensory nuclei
- somatic sensory nuclei (afferents synapse)
- visceral sensory nuclei
ventral horn: motor nuclei
- somatic motor nuclei (efferents leave)
- autonomic efferent nuclei
68
white matter in spinal cord
tracts of axons carrying info to (ascending) and from (descending) the brain
69
ascending tracts
sensory information
70
descending tracts
motor information
71
spinal reflex
sensory information enters the spinal cord → acted on without input from brain
sensory info about stimulus might still be sent to the brain
response initiated without brain's input
72
spinal cord injury
damage at given level affects sensation + motor control below that level
73
Brown-Sequard syndrome
injury to one side of the spinal cord
loss of pain, temp, + light touch on contralateral side
loss of vibration, motor function, deep touch, + position on ipsilateral side
74
biogenic amines
catecholamines - DA, NE, E
seotonin
75
amino acids
excitatory = glu
inhibitory = GABA + glycine
most common in CNS
76
nAChR
fast EPSP
77
mAChR
slow EPSP
78
NE
important in CNS - alertness, attention, cognitive function, stress reactions (anxiety)
79
serotonin
neuromodulatory (+ NT) at every structure in brain + spinal cord
16 receptor subtypes
excitatory or inhibitory
regulates food intake, reproductive behaviour, emotion
80
SSRI
treatment for depression
81
LSD
stimulates brain 5HT 2A receptor = visual hallucinations
82
glutamate
excitatory
50% of exc synapses in CNS
ionotropic + metabotropic receptors
83
glycine + GABA
inhibitory
ionotropic - Cl- selective
too much = loss of consciousness, coma
too little = seizure
homeostasis
84
learning
acquisition of information as a consequence of experience
85
memory
storage of learned information
ability to retain + recall info
86
declarative memory (explicit)
retention and recall of experiences
recall needs conscious attention
consolidation =
st: hippocampus, amygdala, limbic system
lt: association areas
87
procedural memory (implicit)
memory for skilled behaviours
independent of conscious understanding
consolidation =
st: widely distributed
lt: sensorimotor cortex, basal nuclei, cerebellum
88
short term memory
(working)
susceptible to external interference
89
long term memory
survive disruptions
days to years
90
consolidation
short term to long term memory
91
long term potentiation
category of synaptic plasticity
synapses are potentiated
lasting increase in effectiveness
processes alter gene expression
new proteins → more synapses, more transmitters, more receptors on postsynaptic membrane
92
wernicke's area
understanding language/comprehension
93
broca's area
produces speech/expression
94
integration of spoken language
read words: eye → visual cortex → wernicke's area → broca's area → motor cortex
hear words: ear → auditory cortex → wernicke's area → broca's area → motor cortex
95
wernicke's aphasia
receptive aphasia
unable to understand sensory input
96
broca's aphasia
expressive aphasia
unable to understand complicated sentences
difficulty speaking or writing normal syntax
97
global aphasia
both receptive and expressive
damage to both areas
98
EEG
measures electrical activities in the brain using electrodes
diagnostic tool
pattern changes in sleep
99
stages of sleep
nREM: n1, n2, n3
REM
EEG shifts to lower frequency, larger amplitude wave patterns
100
n1
light sleep
theta waves intersperse alpha pattern
101
n2
both theta + delta waves
sleep spindles
K complexes
102
n3
delta waves
slow wave / deep sleep
103
beta rhythym
alert
small amplitude, high frequency
104
alpha rhythym
drowsy
relaxed with eyes closed
higher amplitude + higher frequency waves
105
REM
paradoxical sleep: intense EEG activity (similar to alert state)
deep sleep
dreaming
50-90 min after sleep onset
106
sleep
homeostatic requirement
deprivation → impairs immune system, cognitive + memory deficits, psychosis + death
reactivation of neural pathways
107
motivation
internal signals that shape voluntary behaviours
reticular activation system includes mesolimbic + mesocortical dopamine pathways
108
emotion
results from relationship between individual and environment
internal attitudes
external responses
forebrain structures: modulation, direction, understanding
limbic areas: inner emotions
lateral hypothalamus: rage response
109
primary motivated behaviour
homeostasis
110
secondary motivated behaviour
pleasure or addictive behaviours
reward + punishment
111
dementias
neurodegenerative disorders with decline in memory and other cognitive skills that reduce a person's ability to perform everyday activities
112
Alzheimer's disease
abnormal deposits of proteins form amyloid (neuritic) plaques and tau (neurofibrillary) tangles in brain - medial temporal lobe + cortical structures
most common cause of dementia in older adults
slowly progressive
shrinkage of cerebral cotex
enlarged ventricles
shrinkage of hippocampus
113
senile plaques
deposits of beta-amyloid protein
abnormal accumulation in hippocampus, amygdala, cerebral cortex
damages axons, dendrites, synapses
114
neurofibrillary tangles
clumps of hyperphosphorylated tau protein
accumulates in cytoplasm, axons, + dendrites
115
synaptic loss
defects in axonal transport
loss of dendritic spines, presynaptic terminals, axons
116
ACh hypothesis of AD
ACh - learning + memory
B-amyloid affects ACh neurotransmission
reduced choline uptake + release
→ degeneration of neurons
117
AD risk factors
age - late onset (65+)
genetics - mutations in APP, PSEN-1, PSEN-2,, ApoE
sex - females
lifestyle
medical factors
environmental causes
118
Parkinson's disease
degenerative progressive disorder
affects neurons in substantia nigra - pars compacta (basal ganglia)
dopaminergic neurons - control of body movement + muscle tone
idiopathic = unknown cause
119
symptoms of PD
appear after 60-70% of DA neurons are lost
parkinsonian gait
bradykinesia
reduced arm swing (muscle rigidity)
akinesia
emotionless face
asymmetric resting tremor
shuffling steps
120
tx for PD
increase DA in SN
L-dopa (precursor to DA) → can cross BBB
DBS - stimulation of basal ganglia to reduce symptoms
121
ALS
progressive neurodegenerative disease of upper + lower motor neurons
degeneration of axons in anterior + lateral corticospinal tracts
excitotoxicity
sporadic (not genetic)
first onset of symptoms between 50-65
122
symptoms of ALS
muscle weakness, twitching, cramping
slurred speech
trouble swallowing
impairment of muscles
123
risk factors of ALS
age + sex (higher in males)
smoking, environmental factors
