CNS Flashcards
1
Q
cerebral hemispheres form “convolutions”
A
increases surface area; more neurons fit in limited space
2
Q
cerebral hemispheres (3 parts)
A
cerebral cortex
white matter
basal nuclei
3
Q
How many lobes does the cortex have?
A
5: Insula Frontal Parietal Temporal Occipital
4
Q
4 adult brain regions
A
cerebral hemispheres
diencephalon
brain stem
cerebellum
5
Q
Diencephalon (3 parts)
A
Thalamus
Hypothalamus
Epithalamus
6
Q
Brain stem (3 parts)
A
midbrain
pons
medulla oblongata
7
Q
canal surrounded by…
A
gray matter and then white matter
8
Q
tracts
A
bundles of axons in CNS
9
Q
nuclei
A
clusters of cell bodies in CNS
10
Q
white matter
A
mostly myelinated axons
11
Q
gray matter
A
neuron cell bodies
12
Q
ventricles
A
all connected cerebrospinal fluid (CSF) Lined by ependymal cells (type of neuroglia)
13
Q
gyri
A
ridges
14
Q
sucli
A
grooves
15
Q
fissure
A
very deep sulcus serparates major brain regions
16
Q
longitudinal fissure
A
divides L & R hemispheres
17
Q
transverse cerebral fissure
A
divide hemis from cerebellum
18
Q
cerebellum
A
near brain stem
brain rests on skull fossae
19
Q
frontal deals with
A
motor
20
Q
back deals with
A
sensation
21
Q
cortex (gray matter)
A
conscious mind
no fiber tracts (bundles of axons)
neuron cell bodies, glial cells, blood vessels
22
Q
cerebral cortex (3 functional areas)
A
sensory, motor, associaton
23
Q
cerebral cortex contains what kind of neurons?
A
interneurons
24
Q
contralateral control
A
opposite side
25
although symmetrical, each has...
specialization
26
oversimplification
tasks require whole cortex, not just one region
27
primary motor cortex
conscious control of skeletal muscles in precentral gyrus
28
premotor
plans movement for complex tasks; sends impulses to PMC
29
Broca's (left hemisphere only)
speech muscles
30
Frontal eye field (part in both frontal and parietal lobes)
voluntary eye movements
| around intersection of middle frontal and precentral gyri
31
motor map in precentral gyrus
| primary motor cortex
"upside down" in brain
| more neurons associated with precise control
32
sensory map in postcentral gyrus
| primary somatosensory cortex
"upside down"
| more neurons associated with higher sensitivity
33
Conscious awareness of sensation
parietal, occipital, temporal, insular
34
Neurons receive information from sensory receptors in skin and proprioceptors (which determine position); in postcentral gyrus of parietal lobe
primary somatosensory cortex
35
Integrate sensory inputs. (“What am I touching?”)
somatosensory association cortex
36
primary visual cortex
Receives info from retina; in occipital lobe
37
Recognition of what we see. (“That’s a flower!”)
visual association area (occipital lobe)
38
primary auditory cortex
Interprets pitch, loudness, location; temporal lobe
39
auditory association area
Perceives what we hear. (“That’s a song!”)
40
Vestibular (equilibrium) cortex
| located in insula and parietal lobes
balance
41
primary olfactory cortex
smell
| temporal lobe
42
gustatory cortex
taste
| insula lobe
43
visceral sensory area (insula)
Conscious perception of visceral sensations (e.g., upset stomach, full bladder, etc.)
44
information flow in the brain
sensory receptor
primary sensory
sensory association
multimodal association
45
once decision about motor output made it goes from
premotor cortex to primary motor cortex
46
most of the cortex consists of
multimodal association areas (conscious thoughts, makes us who we are)
47
3 parts of multimodal association areas
anterior
posterior
limbic
48
limbic
emotional impact makes memories meaningful
| Cingulate gyrus, parahippocampal gyrus, hippocampus
49
Anterior association area (a.k.a., prefrontal cortex)
most complex
Intellect, learning, memory, personality, abstraction, judgment, reasoning, planning
slow development in children
50
posterior association cortex (temporal, parietal, occipital lobes)
Recognition of patterns and faces, localization (“Where am I?”), language
Awareness of self in space
51
brain lesions in anterior association area
loss of judgement, attentiveness, inhibitions
| oblivious to social restraints
52
brain lesions in posterior association area
feel contralateral body parts "don't belong to them"
| not want to wash/dress these body parts
53
Phineas Gage
```
scientists learned prefrontal cortex tightly linked to personality
epileptic seizures (from frontal lobe)
```
54
Left
math, language, logic
55
Right
visual, spatial, intuition, emotion, art, music
56
use all of brain
don't only use 10% of brain
57
in about 10% of people
hemisphere roles are opposite or shared equally
58
white matter is communication between
hemispheres and lower CNS
59
associative fibers (white matter) connect...
parts of the same hemisphere
60
commissural fibers (white matter) connect...
corresponding areas of gray matter in cortex
61
largest commissure is...
corpus callosum
62
projection fibers (white matter) connect...
cortex with lower CNS
63
projection fiber function
Transmit sensory input to cortex
| Transmit motor output from cortex
64
neuron cell bodies (nuclei) deep within the cerebral hemispheres
basal nuclei
65
3 basal nuclei
Caudate nucleus
Putamen
Globus pallidus
66
Basal nuclei function
unclear,
| stabilize movement, filter incorrect responses
67
Parkinson's and Huntington's involve a problem with
basal nuclei
68
Diencephalon (3 parts)
thalamus
hypothalamus
epithalamus
69
thalamus
"gateway" to cerebral cortex
70
1) The relay station (info into cerebral cortex)
2) Afferent impulses and most inputs headed for cerebral cortex go through this
3) sensation, motor activities, learning, memory, etc.
Thalamus functions
71
Hypothalamus functions
1) Main visceral control center; homeostasis
2) controls endocrine system
3) autonomic nervous system (blood pressure, sleep/wake cycle)
72
Pineal gland secretes melatonin, which regulates sleep cycle
epithalamus
73
midbrain
visual reflex center
| startle reflex
74
```
Dark color (melanin), a precursor of dopamine
Releases dopamine
Degeneration of dopamine-releasing neurons (Parkinson’s disease)
```
substantia nigra in midbrain
75
Red from blood vessels and iron pigment
| Involved as motor neurons in limb flexion
red nuclei
76
pons
means "bridge"
made of conduction tracts
Projection fibers connect higher brain centers with spinal cord
Other fibers connect it with cerebellum, which relay conversations between motor cortex and cerebellum
77
medulla oblongata
goes through foramen magnum
| contains "pyramids"
78
what are pyramids?
tracts of nerves connect motor cortex (in precentral gyrus) to spinal cord
79
what is the discussation of pyramids
cross-over (contralateral activity)
80
3 centers associated with medulla oblongata
cardiovascular center
respiratory center
visceral motor nuclei involved in coughing, sneezing, hiccupping, vomiting, etc.
81
cerebellum
two apple-sized cerebellar hemispheres
Outer cortex of gray matter
Internal white matter
Deep gray matter nuclei (paired)
82
cerebellum: contralateral or ipsilateral?
ipsilateral
83
cerebellum function
precise timing of skeletal muscle contraction
balance/posture
similar to autopilot (injury=clumsy movement)
84
limbic system
fight-flight-freeze;food;fornicate
| portions of cerebral hemis & parts of diencephalon
85
amygdala
helps respond to perceived threats
| memorable smells
86
psychosomatic illness (physical senses arise from emotional issues)
hypothalamus involved in emotional responses
87
Reticular Activating System (RAS)
keeps cerebral cortex alert by sending it sensory information
Filters out repetitive stimuli
(injury: LSD interferes with this and causes an overwhelming sensory overload; severe injury can cause coma)
88
function of basal nuclei overlaps with...
cerebellum
89
review summary slides 37--
yes
90
Electroencephalogram
measures voltage differences between cortical waves
91
brain waves
Unique, like fingerprints
| Based on synaptic activity, not action potentials
92
brain wave amplitude reflects...
```
synchronous activity of many neurons
high peaks (neurons doing something in sync)
```
93
too high/too low frequency EEG
unconsciousness
94
no brain waves
brain dead
95
alpha waves
awake, but relaxed
96
beta waves
awake, alert
97
theta waves
common in children
98
delta waves
deep sleep, indicates brain damage if awake
99
Slight pressure can injure neurons; brain protected by 4 things:
skull (bone)
meninges (membrane)
cerebrospinal fluid (watery cushion)
blood-brain barrier
100
Meninges (sing: meninx) 3 layers:
```
dura mater (tough mother)
arachnoid mater (spider mother)
pia mater (gentle mother; like tight ceran wrap)
```
101
meninges function
protect CNS and blood vessels
contain CSF
form skull partitions
102
dura mater
2 layers
periosteal layer not in spinal cord
meningeal layer surrounds brain and spinal cord
103
arachnoid mater
separated from dura mater by serous subdural space contains fluid
contains largest blood vessels in brain
104
pia mater
many blood vessels
| clings tightly to every convolution
105
CSF
nourish brain, remove wastes, chemical signals
106
Choroid Plexeus
thin-walled, permeable capillaries
| Surrounded by pia mater and ependymal cells (ciliated cells help circulate CSF)
107
Joined by tight junctions and contain ion pumps
| Allows strict control of contents of CSF
Ependymal cells:
108
CFS circulates around CNS
| recycled 3x a day
1) through ventricles
2) subarachnoid space
3) Absorbed into dural venous sinuses (a separation between the two layers of the dura mater)
4) Returns to bloodstream
109
hydrocephalus
caused when CSF drainage blocked from draining into cardiovascular system
newborns, because bones haven't fused yet
110
Blood brain barrier (3 main parts)
1) Tight junctions no pores between endothelial cells (which form capillary wall)
2) Thick basal lamina (surrounds capillary walls)
3) Astrocytes (which send signals to the endothelial cells to form tight junctions)
111
allowed through blood brain barrier
Via facilitated diffusion: Glucose, essential amino acids, some electrolytes (Na)
Because BBB can’t stop them: Fats, oxygen, CO2, fat-soluble molecules (also: alcohol, nicotine, anesthetics)
112
Denied from entering blood brain barrier
Wastes, proteins, nonessential amino acids, potassium ions (K+), most drugs
113
Alteration in brain function following blow to head
concussion
114
Bruising and permanent damage of brain; if in brain stem, causes coma
contusion
115
Bleeding into these spaces; patient is initially fine and then deteriorates; can cause of loss of control of blood pressure, heart rate and respiration (if brain stem forced down through foramen magnum)
Intracranial hemorrhages:
| subdural or subarachnoid hemorrhage
116
Blocked blood vessel causes brain tissue to die (87% of strokes)
clot blocking blood flow to area of brain
Ischemic stroke
117
Burst blood vessel (blood creates pressure on brain tissue)
| bleeding inside or around brain tissue
Hemorrhagic stroke
118
Temporary blockage;“red flag” for a serious stroke
Transient Ischemic Attack (TIA)
119
1) Extracellular to neuron aggregations of beta-amyloid peptide (called “plaques”); bad kid gets other kids to join gang
2) Intracellular aggregations of tau protein (called “neurofibrillary tangles”);
3) Plaques and tangles form because the proteins involved mis-fold and then cause other normal copies of the proteins to mis-fold.
As brain cells die, functions are lost and the brain shrinks
Alzheimer's
120
plaques
proteins misfold outside of neurons
121
neurofibrillary tangles
proteins misfold inside of neurons
122
spinal cord ends at...
L1 or L2
123
spinal cord is a...
major reflex center
124
conus medullaris
end of spinal cord
125
filum terminale
anchors spinal cord to coccyx
126
cervical and lumbar enlargement
where nerves serve upper and lower limbs
127
cauda equina "horse's tail"
collection of nerve roots beneath spinal cord
128
spinal cord protected by....
bone (vertebrae)
meninges
CSF
129
dura mater has how many layers in the spinal cord?
1
130
epidural space
above dura mater, padded with fat and veins
131
spinal nerves CNS or PNS
PNS
132
ventral roots include motor (efferent) neurons of
somatic (voluntary) motor neurons
| visceral (autonomic) motor neurons
133
dorsal roots include sensory (afferent) fibers of
somatic sensory
visceral sensory
cell bodies of sensory neurons cluster at dorsal root ganglion
134
ascending
sensory up
135
descending
motor down
136
paraplegia
loss of function in lower limbs
| severance between T1 and L1
137
quadriplegia
loss of function in all limbs
| severance in cervical region
138
ALS
motor neurons of ventral gray matter and pyramidal tracts
| lose ability to speak, swallow, breath
139
4 generalizations of Neuronal Pathways
1) decussation--cross over (contralateral)
2) relay--pathway involves chain of 2-3 neurons
3) somatotopy--tract fibers reflect orderly mapping of body
4) symmetry--pathways paired symmetrically, with one member on each side of spinal cord/brain
