central nervous system Flashcards
1
Q
are afferent signals the ones leaving or coming into the CNS?
A
entering
2
Q
are efferent signals the ones coming in or leaving the CNS?
A
leaving
3
Q
what does the CNS consist of?
A
brain and spinal cord
4
Q
what does the PNS consist of?
A
afferent and efferent neurons outside the brain and spinal cord
5
Q
what does the ANS consist of?
A
parasympathetic and sympathetic
6
Q
what are the major cells of the CNS
A
glial cells and neurons
7
Q
what are neurons and where are they found?
A
effectors/sensors, gray matter
8
Q
what are glial cells and where are they found?
A
protection and support cells
white matter
9
Q
name the types of glial cells
A
oligodendrocytes, astrocytes, microglia, ependymal cells (CNS)
schwann cells, satellite cells (PNS)
10
Q
what system are interneurons located in?
A
CNS
11
Q
what is a nerve and what system are they located in?
A
long bundles of sensory and motor axons in PNS
12
Q
how many cells in the brain are glial cells?
A
half
13
Q
what do astrocytes do?
A
physically support neurons
form the scaffold during fetal brain development
induce formation of the BBB
form neural scar tissue
enhance synapse formation and strengthen transmission via chemical signaling with neurons
14
Q
what do oligodendrocytes do?
A
form myelin sheaths
15
Q
what do microglia do?
A
defense of brain as phagocytic scavengers
16
Q
what do ependymal cells do?
A
line internal cavities of brain and spinal cord
contribute to forming CSF
serve as neural stem sells with potential to form new neurons and glial cells
17
Q
what are the meninges?
A
protective layer
18
Q
how many layers are there to the meninges?
A
3
19
Q
what are the meninges layers and what is their formation?
A
Pia Mater - innermost
arachnoid mater - middle
dure mater - outermost
20
Q
what is the space between the pia mater and arachnoid mater called?
A
subarachnoid space
21
Q
what is the contents of the subarachnoid space?
A
CSF and blood vessels
22
Q
what is CSF?
A
the liquid that the brain and spinal cord float in
23
Q
where is CSF produced?
A
choroid plexus of the ventricles
24
Q
at what ventricle does CSF exit to fill the subarachnoid space?
A
4th ventricle
25
where is CSF reabsorbed into venous blood?
arachnoid villi
26
what are the functions of CSF?
reduces brain weight
provides protective padding
creates a regulated environment
27
what does a spinal tap look for to determine infection?
presence of proteins and blood cells in the CSF
28
how often is CSF replaced in the body?
more than 3x per day
29
what would a problem with CSF indicated?
hydrocephalus
30
what is the most common cause of inadequate blood supply to the brain?
stroke
31
what is the blood brain barrier?
functional barrier between interstitial fluid and blood
32
what is the function of the blood brain barrier?
limits passage of blood born agents, protects brain from toxins and fluctuations in hormones, ions and neuroactive substances
33
what is in the blood brain barrier?
endothelial cells and capillaries
34
what are endothelial cells?
cells that form tight junctions so nothing can get between them, the only option is passage through them
35
what type of substances can penetrate endothelial cells/the blood brain barrier?
lipid soluble (O2, CO2, steroids, alcohol)
36
is the blood brain barrier leaky? if so, why?
yes
allows the brain to sense and respond to chemical changes in the body
37
how much oxygen does the brain get from the heart?
15%
38
can the brain do its job without oxygen?
no, the brain can't produce nay ATP without it
39
how much glucose does the brain use?
half the body's glucose but it does NOT store well
40
what are the roles of the cerebral cortex?
sensory perception
voluntary movement
language
personality
sophisticated mental events
41
what are the roles of the basal nuclei?
inhibition of muscle tone
slow, sustained movement
suppression of useless pattern
42
what are the roles of the thalamus?
relay station
crude sensation
conciousness
motor control
43
what are the roles of the hypothalamus?
regulation of homeostatic functions
link between nervous and endocrine
emotion
basic behavioural patterns
sleep-wake
44
what are the roles of the cerebellum?
balance
enhancement of muscle tone
skilled voluntary movement
45
what are the roles of the brain stem?
peripheral cranial nerves
cardio, respiratory, digestion control
muscle reflexes
reception and integration of synpatic input
arousal and activation of cerebral corex
sleep-wake cycle
RAS controls the overall cortical alertness
46
what is gray matter (cerebral cortex) composed of?
neuronal cells, dendrites and glial cells
47
in what type of matter does neural input and initiation take place?
gray matter
48
what does white matter (core) consist of?
bundles of myelinated nerve fibres that interconnect brain areas
49
how many layers is the cerebral cortex organized into?
6
50
how many lobes are there in the brain?
4
51
what occurs at the occipital lobe?
visual input
52
what occurs at the temporal lobe?
auditory input from cochlea
limbic association
53
what occurs at the parietal lobe?
somatosensory input
54
what occurs at the frontal lobe?
voluntary motor, speaking, thought, personality
primary motor cortex
55
what happens at broca's area?
speech formation
56
where is broca's area located?
frontal lobe
57
what structures does the temporal lobe contain?
hippocampus and amygdala
58
where is the primary motor cortex located?
frontal lobe in front of the central sulcus
59
what does the motor homunculus do?
depicts the location and amount of then motor cortex to be devoted to an output
60
in the frontal lobe, what encodes the force, direction and speed of movement?
neurons
61
does the primary motor cortex initiate voluntary movement?
no
62
what does the premotor cortex do?
signals preparation for movement, correct vs. incorrect action
63
what does the supplementary cortex do?
plays a preparatory role in programming complex sequences, responds to remebered movements
active during action and imagination
64
what does the prefrontal cortex do?
planning and organization of goal-directed behaviour, working memory and decision making
65
what is somaesthetic sensation?
sensation from receptors on the surface of the body (touch, pain, pressure, temp)
66
where is the somatosensory cortex?
in the parietal lobe posterior to the central sulcus
67
what does the sensory homunculus do?
recieves information from different areas. depending on the size of the body part will determine the proportion of the somatosensory cortex devoted to that area
68
what does the associative parietal cirtex do?
integrates touch, vision and audition information in spatial context
69
if the primary somatosensory cortex is damaged on the right side, where will sensory be lost to?
left side of the body
70
what are the association areas?
prefrontal association complex
parietal-temporal-occipital association complex
limbic association complex
71
in what matter is the basal nuclei located?
white matter
72
what are the diseases of the basal ganglia?
parkinsons and huntingtons
73
what causes parkinsons?
degeneration of dopaminergic neurons in substantia nigra (midbrain)
74
what are the characteristics of paarkinsons?
increased muscle tone/rigidity
tremors at rest
difficulty initiating and carrying out movements
75
what is the cause of huntingtons?
degeneration of caudate nucleus
causes overactive motor circuits
76
what are the caracteristics of huntingtons?
chorea
memory problems
77
what are the functionally distinct parts of the cerebellum?
vestibulocerebellum
spinocerebellum
cerebroberebellum
78
what is the vestibulocerebellum responsible for?
balance and eye movements
79
what is the spinocerebellum responsible for?
enhancing muscle tone and coordination of skilled movements
80
what is the cerebrocerebellum responsible for?
plans and initiates voluntary activity and stores procedural memory
81
what is the reticular activating system?
a behavioural state system where neurons initiate
82
what does the reticular activating system influence?
attention, motivation, wakefulness, memory, motor control
83
what system do general anaesthetics target?
the RAS system. blocks the pathway between the RAS and cerebral cortex to create unconciousness
84
what is the limbic system made up of and where is it located?
portions of the cerebral lobes, basal nuclei, thalamus and hypothalamus
surrounds brain stem
85
what neurotransmitters does the limbic system use?
norepinephrine, dopamine and serotonin
86
what mental health issue is associated with defects in limbic neurotransmitters?
depression
87
what is the limbic system associated with?
emotions, basic survival, sociosexual behaviour, motivation and learning
88
what are the cortical structures of the limbic system and their functions?
medial prefrontal cortex - decison making, control of emotions and impulses
cigulate cortex - motivation, drive, mood
medial temporal lobes - episodic memory formation
89
what are the subcortical structures of the limbic system and their functions?
hippocampus - episodic memory formation, context, loaction
hypothalamus - homeostasis, food, water, sex and aggression
amygdala - fear and effective learning
90
what is learning?
acquisition of knowledge based on experinece and/or instruction
91
what is memory?
storage of acquired knowledge for later recall.
short term
long term
working
92
what is a memory trace?
a neural change responsibke for retention or storage of knowledge
93
what is declarative memory and what part of the brain does it involve?
what memories.
people, faces, facts, events
hippocampus
94
what is procedural memory and what part of the brain does it involve?
how to memories.
involves cerebellum
95
what part of the brain does consolidation of short term memories to long term involve?
medial temporal lobe
96
short term memory involves transient changes in synpatic activity;
true or false
true
97
long term memory involves formation of new, permanent synaptic connections;
true or false
true
98
what does habituation do?
decreases the responsiveness to a repetitive stimuli
99
what does sensiitization do?
increases responsiveness to mild stimuli following an event
100
where does working memory take place?
prefrontal cortex
101
what is a cholinergic neuron?
neurons that use acetylcholine as their neurotransmitter
102
what is alzheimer's characterized by?
short term memory loss early on
long term memory loss eventually
personality changes
confusion
disorientation
103
what are the brain alterations for alzheimers?
neurofibrillary tangles
amyloid plaques
loss of cholinergic neurons in the basal forebrain
104
what does warnicke's area interpret?
language
105
what is aphasia?
dysfunction of dominant cerebral hemisphere
106
what is a speech impediment?
defects in mechanical aspect of speech
107
what is dyslexia?
difficulty learning to read because of inappropriate interpretation of words
108
what can an EEG determine?
seizure tendancies
death
stages of sleep
109
when would you see an alpha wave? (8-13 Hz)
awake but relaxed
110
when would you see a beta wave? (13-30 Hz)
alert and attentive
111
what is seen in paradoxial sleep?
rapid eye movement (REM)
112
how long does it take to move from stages 1-4 in sleep?
35-45 mins
113
when entering REM sleep what stage is skipped?
stage 1
114
what is paradoxial sleep characterized by?
an EEG similar to an awake person
