nervous system Flashcards
1
Q
protection of brain
A
skull-> bone that encloses the brain
meninges-> membrane that covers and protects the CNS
CSF-> watery cushion that protects CNS from trauma
BBB-> prevents foreign substance from entering the CNS
2
Q
CSF formation
A
formed via choroid plexus located in pia matter
choroid plexus hangs from each ventricle
arachnoid villi allows for CSF resorption
ependymal cells use ion pumps to control comp. of CSF and help cleanse CSF by removing wastes
3
Q
order of CSF flow
A
ventricles-> median and lateral apertures-> subarachnoid space-> arachnoid villi
3
Q
theta waves
A
common in children
Ex: distracted child
3
Q
cerebellum
A
allows for smooth, coordinated movements
maintains balance and posture
all fibers are ipsilateral (superior, middle, inferior)
contains arbor vitae-> treelike pattern of white matter
connected by vermis
3
Q
beta waves
A
awake and alert
Ex: studying
3
Q
REM
A
skeletal muscles except ocular muscles and diaphragm are actively inhibited
dreaming occurs
3
Q
NREM
A
delta waves-> deep sleep, arousal is difficult, nightmares may occur in stages 3 and 4
alpha waves-> relaxation occurs and arousal is easy in stage 1
4
Q
STM
A
temporary holding of info
Ex: phone numbers
involves hippocampus and surrounding temporal lobes
5
Q
LTM
A
has limitless capacity
involves hippocampus and surrounding temporal lobes
6
Q
limbic system
A
emotional or affective brain
puts emotional responses to odors
amygdaloid body-> anger, fear, danger response; plays role in memory
cingulate gyrus-> resolves mental conflicts; plays role in body language
7
Q
recticular formation
A
maintains consciousness and alertness
filters out repetitive, familiar, or weak stimuli
helps control coarse limb movements
regulate visceral motor functions (vasomotor, cardiac, and respiratory centers)
8
Q
gyri
A
ridges
9
Q
sulci
A
shallow grooves
10
Q
fissures
A
deep grooves
Ex: longitudinal and transverse fissures
11
Q
cerebral cortex
A
made up of gray matter
white matter is deep to it
basal nuclei is deep to white matter
12
Q
frontal lobe
A
primary motor cortex
premotor cortex
broca’s cortex
frontal eye fields
prefrontal cortext
13
Q
parietal lobe
A
primary somatosensory cortex
somatosensory association cortex
vestibular cortex
14
Q
insula
A
vestibular cortex
gustatory cortex
visceral sensory area
15
Q
temporal lobe
A
primary olfactory cortex
16
Q
posterior association areas
A
involved in understanding written and spoken language-> wernicke’s area (temporal lobe)
17
Q
prefrontal cortex
A
involved w/ intellect, cognition, recall, and personality
contain working memory needed for abstract ideas, judgement, reasoning, persistence, and planning
aka anterior association area
18
Q
diencephalon
A
thalamus
hypothalamus
epithalamus
19
Q
thalamus
A
sensation
motor activities
cortical arousal
learning and memory
20
hypothalamus
controls ANS and physical responses to emotions
hunger
thirst
water balance
satiety
body temp.
sleep-wake cycles
endocrine cycles
21
epithalamus
secretes melatonin via pineal gland
22
brainstem
midbrain
pons
medulla oblongata
23
midbrain
pain suppression
visual and auditory relay stations
contains periaqueductal gray matter, corpora quadrigemina, substantia nigra, and red nucleus
24
pons
maintains normal rhythm of breathing (pneumotaxic center)
25
medulla oblongata
cardiac and respiratory centers
26
substanstia nigra
produces dopamine
27
corpora quadrigemina
superior colliculi-> visual reflex centers
inferior colliculi-. auditory reflex centers
28
commissures
fibers that connect gray matter between the two cerebral hemispheres
29
the ventral posterolateral nuclei are located in the
diencephalon
30
association fibers
communicate between gyri in the same hemisphere
31
corpus callosum
connect the two hemispheres and allow communication and the sharing of info
32
projection fibers
connect hemispheres with lower brain or spinal cord
33
subcortical nuclei (basal nuclei/ganglia)
caudate nucleus
putamen
globus pallidus
34
functions of basal nuclei/ganglia
influence muscle movements
role in cognition and emotion
35
suprachiasmatic nucleus
biological clock
in hypothalamus
36
superior cerebellar peduncles
connects cerebellum to midbrain
37
middle cerebellar peduncles
connects pons to cerebellum
38
inferior cerebellar peduncles
connects medulla to cerebellum
39
procedural memory
dopamine from substantia nigra is necessary
40
LTP
glutamate binds to NMDA receptors, opening Ca2+ channels in postsynaptic terminals
41
cauda equina
collection of nerve roots at inferior end of vertebral column
42
ventral and dorsal median fissure/sulcus
lengthwise grooves that partially divide cord into right and left halves
43
gray commissure
connects masses of gray matter
encloses central canal
44
funiculi
white columns divided into dorsal, lateral, and ventral parts
45
conus medullaris
terminal end of spinal cord
46
white matter
ascending
descending
transverse
47
filum terminale
extends to coccyx
anchors spinal cord
fibrous extension of conus covered w/ pia matter
48
dorsal root (spinal) ganglia
cell bodies of sensory neurons
49
lateral horns
sympathetic neurons
only in thoracic and superior lumbar regions
50
ventral horns
motor neurons
descending
51
dorsal root
sensory neurons
ascending
52
dorsal horns
interneurons
both sensory and motor
53
ascending tracts
sensory
spinocerebellar
spinothalamic
dorsal columns
54
descending tracts
motor
pyramidal (corticospinal)
extrapyramidal
55
first order neurons
synapses at the medulla oblongata
carries afferent impulse from proprioception and sends them into spinal cord
56
second-order neurons
carries afferent impulse via the spinal cord
synapses at the thalamus
57
third-order neuron
carries afferent impulse via the thalamus
synapses at the cerebral cortex (sensory cortex-> parietal lobe)
58
epidural space
cushion of fat and network of veins in the space b/w vertebrae and spinal dura matter
59
reticulospinal tracts
maintains balance and posture
60
rubrospinal tracts
controls flexor muscles
61
upper motor neurons
pyramidal cells in primary motor cortex
62
lower motor neurons
ventral horn motor neurons
innervate skeletal muscles
63
direct pathways
pyramidal tracts (corticospinal)
synapse w/ interneurons/ventral horn motor neurons
descend w/o synapsing
fast/fine skilled movements
64
indirect pathways
all others
includes brainstem motor nuclei
complex and multisynaptic
65
spinothalamic
temp
pain
pressure
light touch
66
dorsal column
proprioception
deep pressure
vibration
composed of fasciculus cunelus and fasciculus gracilis (in spinal cord and medial lemniscus)-> medulla to thalamus
aka medial lemniscal pathways
second order neurons
67
spinocerebellar
proprioception
second order neurons
68
pyramidal (corticospinal)
skeletal muscle tone
voluntary muscle movement
69
extrapyramidal
skeletal muscle activity
balance and posture
70
transverse tracts
from one side to other (commissural fibers)
71
subdural space
b/w dura (outer) and arachnoid (middle) mater
72
subarachnoid space
b/w arachnoid (middle) and pia (inner) mater
73
central canal
carries CSF
74
cervical enlargement
nerves that supply to the upper limbs
75
sensory receptors
specialized to respond to change in environment
activation results in graded potentials that trigger nerve impulses
76
sensory adaptation
change in sensitivity in presence of constant stimuli
receptor membranes become less responsive
receptor potentials decline in frequency or stop
77
mechanoreceptors
both extero and interoceptor
respond to touch, vibration, and stretch
78
thermoreceptor
nonencapsulated
respond to temp
79
photoreceptor
respond to light
80
chemoreceptor
interoceptor
respond to chemicals
81
nociceptor
contain vanilloid receptors
exteroceptor
nonencapsulated
respond to pain
82
proprioceptors
respond to stretch in areas of the skeletal and muscular system
inform brain of one's movements
83
other nonencapsulated dendritic endings
tactile (merkel) discs-> fine touch
hair follicle receptors-> fine touch
84
encapsulated dendritic endings
all other mechanoreceptors
tactile (meissner's) corpuscles= discriminative touch
lamellar (pacinian) corpuscles= deep pressure and vibration
bulbous corpuscles (contain ruffini endings)= deep continuous pressure
muscle spindles, tendon organs, and joint kinesthetic receptors
85
phasic receptors
fast adapting
signal beginning or end of stimulus
respond to pressure, touch, and smell
86
tonic receptors
adapt slowly or not at all
are nociceptors or most proprioceptors
87
nerve regeneration
only PNS fibers are able to regenerate
CNS fiber never regenerate (oligodendrocytes bear growth inhibiting proteins and astrocytes form scat tissue containing chondroitin sulfate)
88
monosynaptic reflex
provides direct communication b/w sensory and motor neurons innervating muscle
Ex: knee-jerk reflex (stretch reflex)->shortening/contracting
89
polysynaptic reflex
utlilizes interneurons which pass signals b//w sensory and motor neurons (multiple synaptic connections)-> motor neuron, spinal cord, axon, muscle, sensory axons, etc.
Ex: withdrawl, tendon (lengthening/relaxation), and crossed extensor reflex
90
ipsilateral reflex
withdrawl and knee-jerk reflex
91
contralateral
crossed extensor reflex
91
ascending pathways
circuit level sensory integration
91
precommand areas of the brain
basal nuclei and cerebellum
highest level of hierarchy or motor control
91
spinal nerves
31 total
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
92
rami communicates
joins ventral rami in thoracic region
autonomic pathways
93
cervical plexus and neck
formed by ventral rami (C1-C5)
phrenic nerve controls diaphragm (C3-C5)
94
brachial plexus and upper limbs
formed by ventral rami (C5-C8 and T1)
95
median nerve
innervates skin
flexor muscles in anterior forearm pronate
thumb opposition muscles
damage can cause carpal tunnel
usually damaged through suicide attempts
96
ulnar nerve
supplies flexor muscles of anterior forearm
most intrinsic hand muscles
skin of medial aspect of hand
wrist/finger flexion
"funny bone"
97
radial nerve
innervates essentially all extensor muscles, supinators, and posterior skin of limb
98
anterolateral thorax and abdominal wall
form intercostal nerves that supply intercostal muscles, muscle and skin of anterolateral thorax, and most of the abdominal wall
99
lumbar plexus
L1-L4
innervates thigh, abdominal wall, and psoas muscle
contains femoral nerve (quads, sartorius, iliacus)
100
sacral plexus
L4-S4
serves the buttock, lower limb, pelvic structures, and perineum
contains sciatic nerve (hamstrings and adductor magnus)-> longest and thickest nerve of body/combo. of common fibular and tibial nerve
101
dermatome
area of skin innervated by cutaneous branches single spinal nerve (except C1)
assessed extend of spinal cord injuries ascertained by affected dermatomes
102
somatic reflexes
activate skeletal muscle
103
autonomic reflexes
activate visceral effectors (smooth or cardiac muscle of glands)
104
spinal somatic reflexes
integration center in spinal cord
effectors are skeletal muscle
105
muscle spindles
3-10 intrafusal muscle fibers wrapped in CT capsule
assesses length of muscle
106
tendon organs
assesses amount of tension in muscle
107
effector fibers
extrafusal muscle fibers
alpha
108
intrafusal muscle fibers
noncontractile
anulospiral endings (primary)= stimulated by rate and degree of stretch
flower spray endings (secondary)= respond to stretch
gamma
109
gamma efferent fibers
maintain spindle sensitivity
contractile end regions innervated
alpha-gamma coactivation maintains tension and sensitivity of spindle during muscle contraction
110
stretch receptors
hypoactive= can indicate peripheral nerve damage or ventral horn injury (diabetes)
hyperactive= can indicate lesions of corticospinal tract (stroke)
111
reciprocal activation
contracting muscle relaxes
antagonist contracts
112
superficial reflexes
elicited by gentle cutaneous stimulation
plantar reflex (L4-S2)
abdominal reflex (T8-T12)
113
babinski's sign
damage to motor cortex or corticospinal tracts
114
crossed extensor reflex
stepping barefoot on broken glass
115
flexor (withdrawl) reflex
finger stick for blood test
116
perceptual detection
ability to detect a stimulus (requires summation of impulses)
117
magnitude estimation
intensity coded in frequency or impulses
118
spatial discrimination
identifying site or pattern of stimulus (2-point discrimination test)
119
referred pain
pain from one body region perceived from diff region
Ex: left arm pain during heart attack
120
feature abstraction
identification of more complex aspects and several stimulus properties
121
quality discrimination
ability to identify submodalities of sensation (sweet or sour tastes)
122
pattern recognition
recognition of familiar or significant patterns in stimuli (melody in piece of music)
123
somatic NS
cell body in CNS
thick
myelinated
contain group A fibers
release Ach
stimulatory
124
ANS
2-neuron chain
preganglionic neuron (CNS)= thin, lightly myelinated
postganglionic (PNS)= in automatic ganglion, nonmyelinated, extends to effector organ
preganglionic fibers release Ach
postganglionic fibers release NE or Ach
stimulatory or inhibitory
125
dual innervation
all visceral organs served by both divisions, but cause opp. effects
126
adrenal medulla
secrete NE and epinephrine into blood
modified sympathetic ganglion
127
cholinergic receptor
bind Ach
nicotinic= stimulatory, causes depolarization, found on SKM cells
muscarinic= inhibitory or excitatory, found on all effector cells
128
adrenergic receptor
releases NE
129
autonomic dysreflexia
uncontrolled activation of autonomic neurons in quadriplegics and those w/ spinal cord injuries above T6
increases BP
is life-threatening
130
hypertension
higher than normal BP
overactive sympathetic vasoconstriction response to stress
treated w/ adrenergic receptor-blocking drugs (alpha and beta blockers)
131
raynaud's disease
exaggerated vasocontriction in fingers and toes
pale, cyanotic, painful
treated w/ vasodilators
132
atrophine
anticholinergic= blocks muscarinic Ach receptors
prevents salivation during surgery and dialates pupils
133
neostigmine
inhibits Ach-esterase= breakdown of Ach
treats myasthenia gravis
134
parasympathetic division
long preganglionic fibers and short post ganglionic fibers
controlled by cranial nerves 3, 7, 9, and 10 (majority of target organs controlled by vagus nerve)
short-lived
highly localized
Ach destroyed by Ach-esterase
135
sympathetic division
preganglionic neurons in T1-L2 (form lateral horns of spinal cord)
pass through white rami communicantes and enter sympathetic trunk (chain or paravertebral) ganglia
responsible for ejaculation and body temp. regulation
long-lasting
widespread
NE inactivated more slowly than Ach
NE and epinephrine hormones from adrenal medulla prolong effects
136
a1 adrenergic receptors
on most blood vessels
vasocontriction
increases BP
137
B1 adrenergic receptors
found on heart, liver, kidneys
increases HR, CO, and BP
release renin from kidneys
138
B2 adrenergic receptors
found on airways and blood vessels going to heart
opens of airways and blood vessels (broncho and vasodilation)
139
B3 adrenergic receptors
found on adipose tissue
lipolysis
140
a2 adrenergic receptors
found on presynaptic autonomic neurons
initiates neg. feedback system
inhibits further NE release
141
beta agonists
dilate lung bronchioles
attach to B2 receptors
142
OTCs
stimulate a-adrengenic receptors
143
S.L.U.D.G.E
salivation
lacrimation
urination
defecation
GI tract motility
erection
(for PNS)
144
the gray rami communicantes contain
postganglionic sympathetic fibers
145
nicotinic receptors
found in adrenal medulla, skeletal muscle, autonomic ganglia
not found in heart
146
fucntions of hypothalamus
main integration center of ANS
visceral responses to emotion
147
the hypothalamus controls the autonomic regions of the brain stem and spinal cord via the
reticular formation
148
the parasympathetic division and the sympathetic division share control w/ the sympathetic over
heart, respiratory system, salivary glands
but not blood vessels
149
autonomic ganglia
contain only motor neurons
150
sympathetic tone
aka vasomotor tone
keeps blood vessels in continual state or partial constriction
alpha-blockers interfere w/ vasomotor fibers (used to treat hypertension)
151
left hemisphere
speech
comprehension
arithmetic
writing
152
right hemisphere
creativity
spatial ability
artistic and musical skills
153
cranial nerves in the midbrain
occulomotor
trochlear
154
cranial nerves in the pons
trigeminal
abducens
facial
vestibulocochlear
155
cranial nerves in the medulla
glossopharyngeal
vagus
hypoglossal
accessory
