Exam 4- Brain and CNS Flashcards
1
Q
process of embryological development
A
- ectoderm thickens along midline to form neural plate
- neural plate invaginates to form neural groove, with neural folds
- neural folds fuse to become neural tube
- neural tube detaches from ectoderm and deepens into embryo
- neural crest develops as offshoot of neural folds
2
Q
what is the first step of formation of the nervous system
A
ectoderm thickening along midline to form neural plate
3
Q
which structure gives rise to the CNS
A
neural tube
4
Q
neural crest becomes ____
A
neural ganglia
5
Q
primary brain vesicles definition
A
swellings on head end of neural tube
6
Q
primary brain vesicles
A
prosencephalon (forebrain)
mesencephalon (midbrain)
rhombencephalon (hindbrain)
7
Q
secondary brain vesicles
A
telencephalon, diencephalon (from prosencephalon)
mesencephalon, myelencephalon (from rhombencephalon)
8
Q
adult brain structures
A
cerebrum hypothalamus thalamus epithalamus midbrain pons cerebellum medulla oblongata
9
Q
telencephalon gives rise to which adult brain structure?
A
cerebrum
10
Q
diencephalon gives rise to which adult brain structures?
A
hypothalamus
thalamus
epithalamus
11
Q
the brainstem comprises which structures
A
midbrain
pons
medulla oblongata
12
Q
mesencephalon gives rise to which adult brain structure?
A
midbrain
13
Q
metencephalon gives rise to which adult brain structures?
A
pons
cerebellum
14
Q
myelencephalon gives rise to which adult brain structure?
A
medulla oblongata
15
Q
lower brain functions
A
primal basal brain activity
ex: breathing, keeping us alive
16
Q
higher brain functions
A
cognition, thought, logic
17
Q
ventricles definition
A
expansions from lumen of neural tube;
interconnected and filled with CSF;
lined with ependyma
18
Q
ventricles of the brain
A
lateral ventricles
third ventricle
fourth ventricle
19
Q
where is CSF located
A
in center of spinal cord and lumen, in ventricles, and on outside of brain/spinal cord
20
Q
lateral ventricles
A
theres 2 of them- 1 in each hemisphere
not directly connected; separated by septum pellucidum
connect to 3rd ventricle
21
Q
septum pellucidum
A
structure in center of brain that separates lateral ventricles
22
Q
third ventricle
A
located where diencephalon was
connects to 4th ventricle
23
Q
fourth ventricle
A
located in hindbrain
connects through central canal of spinal cord
24
Q
connecting channels of brain ventricles
A
interventricular foramen
cerebral aqueduct
25
interventricular foramen
connecting channel
| connects lateral ventricles to 3rd ventricle
26
cerebral aqueduct
connecting channel
| connects 3rd ventricle to 4th ventricle
27
openings of brain ventricles
connect CSF on inside of brain to CSF on outside of brain
lateral apertures
median aperture
28
lateral apertures
openings of brain ventricles
| on each side of 4th ventricle
29
median aperture
openings of brain ventricles
| on roof of 4th ventricle
30
gyri
elevated ridges
| the more ridges, the greater the intellect
31
sulci
depressions between gyri
32
longitudinal fissure
groove in between 2 cerebral hemispheres
| separates left and right
33
transverse cerebral fissure
groove that runs across back end
| separates cerebrum from cerebellum
34
____% of mass of human brain is cerebrum
83%
35
lobes of the cerebrum
```
frontal
parietal
temporal
occipital
insula (underneath)
```
36
regions of cerebrum
cortex
white matter
basal nuclei
37
cerebral cortex region of cerebrum
superficial layer
| made of gray matter
38
what is gray matter made of
cell bodies of neurons
39
white matter region of cerebrum
deep to cortex
| made of myelinated axons
40
basal nuclei
islands of gray matter within white matter
41
the cerebral cortex is involved in what?
our conscious mind
| self awareness, sensations, communication, memory, voluntary movement
42
cerebral cortex thickness
ranges from 2-4 mm thick
43
domains of the cerebral cortex
motor (front)
| sensory (back)
44
T/F Each hemisphere controls the opposite side of the body
True
45
right side of the cerebrum
artsy brain
| visual spacial tasks, emotion, art, music, intuition
46
left side of cerebrum
science brain
| math, logic, language
47
cerebral dominance
each of us has one hemisphere that's dominant to the other
48
functional areas of the cerebral cortex
motor (front)
sensory (back)
association (middle)
49
motor areas
involved in conscious control/voluntary movement of skeletal muscle
primary motor cortex
premotor cortex
Broca's area
frontal eye field
50
Primary motor cortex
where signals for movement leave the cortex
sends motor impulse to allow coarse movement
made of pyramidal cells
51
premotor cortex
learned motor skills, repeated patterns
| refines movement before it goes to the primary motor cortex
52
Broca's area
speech motor area
found only in left hemisphere
has to do with the muscles controlling tongue, larynx, etc
53
frontal eye field
sends signal so we can voluntarily move our eyes
54
sensory areas
has to do with conscious awareness of sensation
```
primary somatosensory cortex
somatosensory association cortex
visual areas:
primary visual cortex, visual association area
auditory areas:
primary auditory cortex, auditory association area
olfactory cortex
gustatory cortex
vestibular cortex
```
55
primary somatosensory cortex
allows us to spatially discriminate different parts of our body
receives sensory info from skin and proprioceptors
56
somatosensory association cortex
integrates all sensory information that goes to the primary somatosensory cortex
why you understand what it is you're feeling
ex: you know it is a tag scratching your back or an ant crawling up your leg
57
primary visual cortex
receives sensory info from the retina
58
visual association area
interprets info from primary visual cortex using experience
59
primary auditory cortex
receives sensory info from inner ear
60
auditory association area
interprets info from primary auditory cortex using experience
61
olfactory cortex
receives info from smell receptors (detects odors)
| has links to emotion
62
gustatory cortex
detects taste from taste buds
63
vestibular cortex
gives us balance-related sensations
| in the insula
64
association areas
links motor and sensory areas
a communication area --> relays signals
prefrontal cortex
language areas
general interpretation area
visceral association area
65
prefrontal cortex
Associated with intellect, cognition, and recall
How we learn new material
linked to personality
develops slowly, relies on social feedback
aka anterior association area
most evolved portion of brain in humans
66
language areas
deal with language comprehension
2 parts: Broca's area and Wernicke's area
Broca and Wernicke only found on left side
right side has areas for body language
67
Broca's area and Wernickes area
Broca: speech
Wernicke: sounding out unfamiliar words
only in left hemisphere`
68
what is in position of broca and wernicke in right hemisphere?
areas for body language
where broca would be: make body language
where wernicke would be: interpret body language
69
general interpretation area
receives info from all sensory association areas --> integrates them all into a single thought
only on left side
ex: roses+candles+boyfriend = romantic
70
visceral association area
links input to fear/emotional response
| ex: upset stomach = throw up
71
function of cerebral white matter
```
carries communication between:
-areas of the cerebrum
-the cortex and lower CNS centers
consists of myelinated fibers bundled into large tracts
deep to cortical gray matter
```
72
white matter fibers
commissures
association fibers
projection fibers
73
commissures
white tracts that connect the gray areas of the 2 hemispheres together
facilitate communication between 2 hemispheres
74
corpus callosum
largest commissure in brain
75
association fibers
connect parts of same hemisphere to each other
76
projection fibers
connect cerebrum to the rest of the nervous system
| sensory and motor info goes through here
77
function of basal nuclei
modify motor activity
regulate attention and cognition
regulate stereotype movement
78
how to basal nuclei direct their actions?
they send their actions through thalamus
| they have no direct access to motor pathways
79
types of basal nuclei
```
caudate nucleus
putamen
globus pallidus
(each of those 3 ^ are in both hemispheres)
amygdala
(^ only one 1 side of brain)
```
80
amygdala
basal nuclei highly linked to emotion
helps with emotional interpretation and response
linked to ANS (fight/flight) and limbic system
only 1 in entire brain
81
thalamus
where all sensory input comes through, is sorted, and is sent to cortex
non-sensory inputs (interneurons) are also sorted and sent here
contains several nuclei (clusters of neural fibers), each with a specialty functions that connect to specific regions of the cortex
82
major visceral control center
hypothalamus
83
hypothalamus
sits below thalamus
regulates ANS activity, body temp, water balance, hormone release
controls emotional responses, food intake, and sleep cycle
84
epithalamus
contains pineal gland, which secretes melatonin
| regulates production of CSF
85
how does melatonin/pineal gland work
when UV radiation is present (day), pineal gland is shut off.
when sun sets (night), pineal gland starts functioning and produces melatonin
melatonin tells the brain to shut down and go to sleep
melatonin is also linked to mood (tired = cranky)
86
brainstem
deep gray matter surrounded by white matter and gray matter embedded in white matter
provide programmed automatic behaviors needed for survival (inhale/exhale, digest, HR, BP)
controlled/regulated by hypothalamus
passageway that links lower brain to upper brain
87
midbrain
contains motor tracts connect to: spinal cord and cerebellum
functions in pain suppression
link between amygdala and ANS
contains visual reflex center
functions as auditory relay
88
visual reflex center
coordinates head movement with eye movement
| located in midbrain
89
pons
mainly composed of conduction tracts
complete pathway between higher brain centers and spinal cord
relays info between cerebrum and cerebellum
90
major autonomic reflex center
medulla oblongata
91
medulla oblongata
controls: HR, blood vessel diameter, rate and depth of breathing
regulates: vomiting, hiccuping, swallowing, coughing, sneexing
92
cerebellum functions
refines skeletal muscle contractions
plays role in cognition, language, and problem-solving
activity occurs subconsciously
93
cerebellum anatomy
```
gray cortex (arbor vitae= tree)
internal white matter with gray matter masses
(composition similar to cerebrum)
```
94
cerebellar processing (PROCESS)
1. motor association areas of cerebral cortex send signals to cerebellum that it wants to initiate voluntary muscle contraction
2. cerebellum receives info from visual receptors, equilibrium receptors, and proprioceptors that say (1) we want to contract muscle and (2) what will happen if we do?
3. cerebellar cortex calculates best way to coordinate force of contraction
4. cerebellum dispatches message to cerebral cortex
5. signal is sent to muscle
95
functional brain systems
networks of neurons that work together, but span relatively large distances in the brain
(systems cannot be localized to specific brain regions)
96
limbic system
"emotional brain"
expresses emotion as gestures
allows us to assess danger, elicit fear response
we have strong emotional ties to odor
strong link between feelings and thoughts
linked to body language
97
the limbic system is closely linked to which primary brain vesicle?
the rhinencephalon
98
output of limbic system is relayed through which brain structure?
hypothalamus
99
T/F the logical part of the brain overrides the emotional part
false!
| the emotional brain overrides the logical part of the brain
100
reticular formation
loosely clustered neurons in the center of the medulla, pons, and midbrain
governs arousal of brain as a whole
101
reticular activation system (RAS)
part of reticular formation that filters sensory input
| when we aren't sleeping, RAS is constantly sending signals to cerebrum to make it work
102
brain waves
pattern of neuronal electrical activity
| Alpha, Beta, Theta, or Delta waves
103
electroencephalogram (EEG)
test that measures electrical activity of brain waves
| this is linked to level of consciousness
104
Alpha waves
8-13 waves per second
| awake, relatively inactive
105
beta waves
> 13 waves per second
| intense concentration
106
theta waves
4-8 waves per second
| common in children (imaginary friends), uncommon in adults
107
delta waves
< 4 waves per second
in deep sleep
if occurring while awake... they have brain damage
108
consciousness
awareness of sensations and control of movement, levels of consciousness are a continuum
109
levels of consciousness (highest to lowest)
```
alert
drowsy
lethargic
stupor
coma
```
110
sleep
state of partial (un)consciousness
"partial" bc we can be aroused from sleep
restorative or REM sleep
111
T/F you can be aroused from a coma by stimulus
false.
112
restorative sleep
our brain is relatively idle, we're throwing delta waves
| body is refreshing and rebuilding from the day
113
REM sleep
our eyes are twitching around, and we're throwing beta waves
| analyzing the day, sorting important vs unimportant stimulus; mechanism to work through problems
114
memory
storage and retrieval of information
| short term or long term
115
learning
establishing connections between neurons
116
short term memory
working memory, limited capacity
117
long term memory
greater storage than short term memory, can be retrieves any time, but if it is never used it may get lost (not 100% kept forever)
118
memory- rehearsal
the more we work with something, the greater our ability to recall it later
119
memory- association
linking new data to old data makes it a lot easier to learn/remember
120
process of encoding information
1. outside stimulus reaches general and special sensory receptors
2a. automatic memory- info goes straight to long term memory
2b. afferent output- info goes to temporary storage in cerebral cortex
3. data selected for transfer- info goes from cerebral cortex to short-term memory
4. data transferred from short term memory to long term memory
5. when needed, info can be retrieved from long term memory to short term memory
* data can be forgotten and permanently lost at any step along the way
121
reasons for data transfer from short term to long term memory
excitement
rehearsal
association of old and new data
122
structures that protect the brain
bone- dense skull
membranes- beneath bone, cover brain
fluid (CSF)- cushions brain, dissipates trauma, exists inside and outside brain
123
meninges
membranes of the brain
cover and protect CNS (surround brain and spinal cord)
protect blood vessels
contain CSF
theres 3 around brain: dura mater, arachnoid mater, pia mater
124
dura mater
superficial meninx
2-layered sheet of fibrous dense irregular CT
strongest covering
attaches to underside of skull to hold everything in place
125
How many layers thick is the dura mater around the spinal cord? How many layers around the brain?
1;2
126
arachnoid mater
middle meninx
layer that all blood vessels run through
creates subarachnoid space
127
subarachnoid space
filled with CSF and larger blood vessels
128
subdural space
tiny space between dura mater and arachnoid mater
| contains tiny bit of CSF
129
pia mater
deepest meninx
| immediately covers brain and nervous tissue
130
which meninx contains CSF?
arachnoid mater
131
cerebrospinal fluid (CSF)
liquid cushion in/around brain and spinal cord
prevents brain from crushing itself by dissipating forces
protects CNS from physical trauma
helps nourish the brain and carries chemical signals
132
CSF reduces brain weight by ___%
97%
133
how is cerebrospinal fluid formed?
choroid plexuses in each ventricle
combo of capillaries and ependyma in roof of each ventricle
plasma leaks out of plexuses and into ventricles to form CSF
134
blood-brain barrier
protective mechanism for brain to help maintain a stable environment
regulates what can be exchanged between circulatory system and neural tissue
is a selective barrier
135
structures of blood-brain barrier that separate substances in brain capillaries from the brain
capillary endothelium (1st thing, has tight junctions)
thick basal lamina on capillaries
astrocytes
136
the blood brain barrier allows which substances to pass through?
amino acids, glucose, electrolytes
137
regions where blood brain barrier is absent
vomiting center
| hypothalamus
138
the spinal cord is developed from the _____
neural plate
139
2 distinct clusters of neuroblasts that make up the spinal cord
alar plate
| basal plate
140
alar plate of spinal cord
on dorsal half of spinal cord
becomes interneurons that carry sensory info to brain
dorsal root ganglion connects here
141
basal plate of spinal cord
on anterior half of spinal cord
| becomes motor neurons that carry motor impulses away from CNS
142
where does the spinal cord extend to/from?
from foramen magnum to first lumbar vertebra (L1)
| ends at "conus medullaris"
143
conus medullaris
terminal end of spinal cord
144
cervical enlargement and lumbar enlargement of spinal cord
sources of most nerves to our limbs
cervical- sends nerves to upper limbs
lumbar- sends nerves to lower limbs
145
2 tracks of the spinal cord
spinal cord has tracks going up and down, bc nerves can only carry impulse in one direction
sensory track goes up
motor track goes down
146
meninges of spinal cord
spinal cord is covered with meninges
single layer dura mater with epidural space
meninges extend beyond conus medullaris
147
meninges extend beyond conus medullaris and anchor to coccyx by _______
filum terminale
148
meninges extend beyond conus medullaris and are secured to dura mater by _______
denticulate ligaments
149
which structure extends sacral and lumber nerves beyond the conus medullaris?
cauda equinis
150
3 structures of spinal cord that help to extend meninges beyond conus medullaris
filum terminale
denticulate ligaments
cauda equina
151
how do we cause a response without message going all the way up to the brain?
spinal reflexes
152
grooves that run length of spinal cord and divide it into R and L halves
anterior median fissure
| posterior median sulcus
153
gray matter in spinal cord anatomy
arranged in an H shape
| anterior, posterior, and lateral horns of each side connected by gray commissure
154
gray commissure
connects horns of gray matter in spinal cord
155
gray matter consists of what type of neurons?
multipolar
156
posterior horns are made of what type of neurons?
interneurons
157
anterior horns are made of what type of neurons?
cell bodies of somatic motor neurons
158
lateral horns are made of what type of neurons?
autonomic motor neurons
159
sensory tract of spinal cord is on the ___ side
| motor tract of spinal cord is on the ___ side
dorsal; ventral
160
white matter of spinal cord
divided into 3 columns: anterior, posterior, lateral
| columns contain collections of fibers that run as multi neuron tracts
161
decussation
most pathways cross from one side of CNS to the other
162
somatropy
spatial relationship that represents orderly mapping of the body
things running from the same parts of the body generally run together
things running to the same parts of the brain generally run together
163
T/F all spinal cord tract pathways are paired
true
| whatever happens on the R side happens on the left
164
most spinal tracts consist of a chain of _____ neurons that contribute to the successive tracts to move things all over the body
2-3
165
first order neurons
cell bodies are in ganglion
conduct impulses from sensory receptors and proprioceptors
sensory neurons that go to spinal cord and brainstem
synapses with 2nd order neuron
166
second order neurons
cell bodies are in dorsal horn of spinal cord OR medulla
transmit impulses to thalamus or cerebellum
interneurons
synapses with 3rd order neuron
167
third order neuron
located in thalamus
conduct impulses to somatosensory cortex of cerebrum
interneurons
168
ascending pathways
nonspecific ascending pathway
specific ascending pathway
spinocerebellar tracts
169
nonspecific ascending pathway
not linked to special senses
stimuli are non-specific
send signals of pain, temp, coarse touch
170
specific ascending pathway
carry info about a single specific type of sensory information
171
spinocerebellar tracts
spine to cerebellum
does not go to cerebral cortex
does not desiccate
carries info about stretches in muscles and tendons
172
descending pathways
direct (pyramidal) system
| indirect (extrapyramidal) system
173
direct (pyramidal) system
motor info
motor pathways linked to fast, fine tuned action
ex: writing, typing
174
indirect (extrapyramidal) system
involved with coarse limb movements
also controls muscles that regulate balance
coordinates eye, head, and neck movement
175
which descending pathway is inhibited when we drink alcohol?
indirect (extrapyramidal) pathway
