Exam #5- Neurology Physiology Flashcards
1
Q
neuroglial cells (neuoglia)
A
“nerve glue”
includes:
astrocytess
oligodendroglia (oligodendrocytes)
ependymal cells
microglia
schwann cells
2
Q
astrocytes
A
fill spaces between neurons and surround CNS blood vessels
3
Q
oligodendroglia (oligodendrocytes)
A
store mylin in CNS
counterpart of schwann cells
schwann cells form INDIVIDUAL myelin sheaths around axons in the PNS, while oligodendroglia form MULTIPLE myelin sheaths on separate axons in the CNS
4
Q
ependymal cells
A
line CSF filled cavities of CNS
5
Q
microglia
A
phagocytosis in CNS (they get rid of debris)
6
Q
schwann cells (neurolemmocytes)
A
wrap around and cover axons in PNS!!
they form and maintain the MYELIN sheath
7
Q
what does the neuro system need for fuel?
A
glucose
8
Q
3 components of a neuron
A
cell body (soma)
dendrites
axons
9
Q
cell body (soma) of neuron
A
located mainly in CNS
have densely packed cell bodies: CNS=NUCLEI, PNS= GANGLIA/PLEXUSES
10
Q
dendrites of neuron
A
carry nerve impulses TOWARD cell body
receive messages from other cells
11
Q
axons of neuron
A
carry nerve impulses AWAY from cell body to other neurons, muscles, or glands
contain: myelin, nodes of ranvier, saltatory conduction
12
Q
myelin
A
in the axon
insulated layer formed/maintained by the SCHWANN CELLS
13
Q
nodes of ranvier
A
in the axon
spaced in between schwann cells
14
Q
saltatory conduction
A
happens in axon
ions flow between myelin segments (instea of the entire length of the axon)
makes the IMPULSE travel FASTER!!!
15
Q
conduction velocity in an axon depends on what?
A
myelin coating and axon diameter
the larger the axon, the faster the travel
16
Q
action potential
A
electrical signal traveling down the axon
17
Q
myelin sheath
A
covers the axon of some neurons and helps speed neural impulses
18
Q
terminal buttons
A
part of the neuron that forms junction with other cells
19
Q
sensory neuron
A
AFFERENT
sends impulses from sensory receptors to the CNS
the conduction travels from the dendrites to the cell body and up the axon to an interneuron
20
Q
associational (interneurons)
A
sends impulses from neuron to neuron
21
Q
motor neuron
A
EFFERENT
sends impulses from CNS to effector organ
the conduction travels down an axon
22
Q
the end processes of a neuron form what?
A
NMJ (in skeletal muscle)
23
Q
what happens when an axon is SEVERED (INURED)?
A
WALLERIAN DEGENERATION= deterioration of nerve fiber that has been separated from its nutritive source (by injury or disease)
24
Q
what cells play a key role in nerve injury?
A
schwann cells and macrophages
25
the process of nerve regeneration is limited to what?
MYELINATED axons in peripheral nerves
26
nerve regeneration depends on what?
location/type of injury, inflammatory response, and scar tissue formed
27
nerve regeneration in the axon distal (below) cut
myeling sheath shrinks/DISINTEGRATES
axon portion deteriorates and disappears
myelin sheaths reform into schwann cells that line up between the cut and effector organ
28
nerve regeneration in the proximal to the injury (above) cut
similar changes to distal but only as far back as the next node of ranvier (cells increase metabolic activity, protein synthesis, and mitochondrial activity; new terminal sprouts project from the proximal segment 7-14 days after injury)
29
the CLOSER the cell body of the nerve to the injury...
more likely it will DIE and not regenerate
30
crushing injury to a nerve allows what?
recovery more fully than a cut injury
31
nerve impulse
NEURONS make and conduct electrical/chemical impulses by **selectively changing the electrical portion** of their plasma membranes and **influencing other nearby neurons by the release of NEUROTRANSMITTERS**
32
synapses
region between adjacent neurons
impulses are transmitted across the synapse via chemical and electrical conduction
neurotransmitters are formed in the neuron
33
presynaptic neurons (toward)
next to synapse
relays impulses TOWARD synapse
34
postsynaptic neurons (away)
farther away from synapse
relays impulses AWAY from synapse
35
synaptic knobs (boutons)
STORE neurotransmitters
neurotransmitters are released across the synaptic cleft (space between neurons) when the AP in the presynaptic neuron causes the synaptic vesicles to release 1 or more NT's
the NT binds to receptor sites on the plasma membrane of the postsynaptic neuron
36
neurotransmitters
norepi, acetylcholine, histamine, GABA, dopamine, serotonin
have effects on postsynaptic neurons
either excited or inhibited
37
excited neurotransmitters
DEPOLARIZED
acetylcholine, norepi, glutamate
38
inhibited neurotransmitters
HYPERPOLARIZED
dopamine, GABA, glycine, serotonin
39
reticular formation
MAINTAINS WAKEFULNESS
network of connected nuclei that regulate vital reflexes (like heart and lung function)
extends through the central core of the medulla oblongota, pons, and midbrain
intricate system composed of loosely clustered neurons in what is otherwise white matter
visual, auditory, touch, pain, temp
40
RAS (reticular activating system)
reticular formation+cerebral cortex
41
forebrain
anterior part of the brain, including cerebral hemispheres, the thalamus, and hypothalamus
42
cerebrum
includes gray matter and white matter
43
gray matter (nuclei)
part of cerebrum
cell bodies and dendrites of neurons in cerebral cortex
receive, integrate, store, and transmit info
44
white matter (numerous tracts)
part of cerebrum
beneath cerebral cortex
composed of myelinated nerve fibers
45
frontal lobe
verbal and physical function
includes prefrontal, premotor, primary motor, and broca speech area
46
prefrontal lobe
GOAL-ORIENTED BEHAVIOR
ST memory
47
premotor area
part of frontal lobe
programs motor movement
48
primary motor area
part of frontal lobe
primary voluntary motor area
49
broca speech area
part of frontal lobe
motor aspect of speech
50
parietal lobe
somatic SENSORY input
51
occipital lobe
VISUAL cortex
52
temporal lobe
primary AUDITORY cortex
WERNICKE AREA=**reception/interpret speech**
LT memory
53
corpus callosum
connects 2 cerebral hemispheres (how 2 sides of brain communicate)
54
limbic system
primitive behavioral responses, expression of affect (emotional/behavioral states), consolidation of memory
55
diancephalon
**processes incoming sensory data** made up of epiTHALAMUS, THALAMUS, hypoTHALAMUS, and subTHALAMUS
56
midbrain
relay center for motor and sensory tracts
center for auditory and visual reflexes
cerebral aqueduct (carries CSF)
57
hindbrain
includes cerebellum, pons, medulla oblongata
58
cerebellum
part of hindbrain
balance and posture
damage is characterized by ipsilateral loss of equilibrium, balance, motor coordination
59
pons
part of hindbrain
controls RR's
60
medulla oblongata
part of hindbrain
controls reflex activities (HR, RR, BP, coughing, sneezing, swallowing, vomiting)
61
cranial nerves
project from brain and pass through foramina in skull
12 pairs (sensory, motor, and mixed)
62
mnemonic for nerves
on old olympus towering tops a finn and german viewed some hops
olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, acoustic, glossopharyngeal, vagus, spinal accessory, hypoglossal
63
mnemonic for sensory, motor or both
some say marry money but my brother says bad business marry money
```
olfactory- sensory
optic-sensory
oculomotor-motor
trochlear-motor
trigeminal-both
abducens-motor
facial-both
acoustic-sensory
glossopharyngeal-both
vagus- both
spinal accessory- motor
hypoglossal- motor
```
64
olfactory
sensory
smell
"some"
"on"
65
optic
sensory
vision
some "say"
on "old"
66
oculomotor
motor
pupil reaction, EOM
some say "marry"
on old "olympus"
67
trochlear
motor
EOM
superior oblique muscles (rotates laterally and intorts- twists in and out- eye)
some say marry "money"
on old olympus "towering"
68
trigeminal
motor and sensory (both)
mastication, face sensation
some say marry money "but"
on old olympus towering "tops"
69
abducens
motor
EOM
lateral rectus; abducts the eye
some say marry money but "my"
on old olympus towering tops "a"
70
facial nerve
motor and sensory (both)
facial expression
taste on front of tongue
some say marry money but my "brother"
on old olympus towering tops a "finn"
71
vestibulocochlear (acoustic)
sensory
hearing
some say marry money but my brother "says"
on old olympus towering tops a finn and
72
glossopharyngeal
motor and sensory (both)
motor fibers work on pharynx and salivary glands
tastes on back of tongue
some say marry money but my brother says "bad"
on old olympus towering tops a finn and "german"
73
vagus
motor and sensory (both)
motor and sensory for pharynx
parasympathetic motor fiber (supplies smooth muscle of abdominal organs)
some say marry money but my brother says bad "business"
on old olympus towering tops a finn and german "viewed"
74
spinal accessory
motor
shrugs your shoulders
some say marry money but my brother says bad business "marry"
on old olympus towering tops a finn and german viewed "some"
75
hypoglossal
motor
tongue muscles
some say marry money but my brother says bad business marry "money"
on old olympus towering tops a finn and german viewed some "hops"
76
which cranial nerve would you be most concerned about if you found that the patient was unable to abduct their left eye?
abducens nerve
77
where is the spinal cord?
in the vertebral canal and protected by vertebral column
78
what does the spinal cord do?
**connects the brain and body, conducts somatic and autonomic reflexes, provides motor pattern control centers, and modulates sensory and motor function**
79
conus medullaris
end of spinal cord
80
cauda equina
nerve bundle at end of spinal cord
81
gray matter
POSTERIOR/DORSAL horn is composed of SENSORY neurons
LATERAL HORN contains cell bodies involved with ANS (INVOLUNTARY)
ANTERIOR/VENTRAL horn contains cell bodies for efferent pathways leaving spinal cord by way of spinal nerves (MOTOR)
82
white matter
spinal tracts are named after their beginning and end point (ex: spinothalamic tract)
contain afferent and efferent tracts
83
afferent tracts
part of white matter
SENSORY
carry impulses TO CNS and away from organs/receptors
84
efferent tracts
part of white matter
MOTOR
carry impulses AWAY from CNS and to organs
85
upper motor neurons
**disruption of UMN's leads to INITIAL paralysis which leads to partial recovery**
pathways are completely WITHIN CNS
efferent pathways relay info from cerebrum to the brain stem/spinal cord
86
upper motor neurons are located where?
in the CNS
87
lower motor neurons
**destruction of LMN's leads to PERMANENT paralysis**
**neurons have DIRECT influence on MUSCLES**
cell bodies ORIGINATE in gray matter of spinal cord but their axons EXTEND into PNS!!
88
meninges
protective membrane that surrounds brain and spinal cord
composed of DURA MATER, ARACHNOID, and PIA MATER
89
subdural space
part of the meninges
CONTAINS CSF
between dura and arachnoid
has bridging veins
90
subarachnoid space
part of the meninges
between arachnoid and pia matter
contains CSF!
91
epidural space
part of the meninges
between dura and skull
92
arterial supply to the meninges is in which dural space?
epidural
93
CO2 regulates what?
CNS blood flow!!!
it is a potent vasodilator
increased CO2 will increase ICP
94
ACA blood flow
supplies frontal and parietal lobes
95
MCA blood flow
supplies frontal, temporal, parietal lobes
96
PCA blood flow
supplies occipital lobe
97
blood brain barrier
cellular structures that prevent harmful stuff from the blood from entering the interstitial spaces of the brain and CSF
this matters because certain drugs are more likely to cross the BBB
98
functions of the blood brain barrier
protects brain from foreign stuff in blood that can cause injury
protects brain from hormones and NT's secreted by other organs
maintains a constant biochemical environment for the brain
99
things that increase permeability/break down BBB
HTN, dilutional hyponatremia, lots of anesthetics, vasodilation, hypercapnia
100
somatic nervous system
VOLUNTARY motor control of skeletal muscle
101
autonomic nervous system
INVOLUNTARY control of organ systems
**located in both CNS and PNS**
102
motor neuron component of autonomic nervous system (PNS)
preganglionic (myelinated) and postganglionic (unmyelinated)
103
preganglionic (myelinated) motor neuron of autonomic nervous system
**located in CNS** (brain stem/spinal cord)
in PNS the preganglionic (efferent fibers) synapse (passing from one to another) with ganglionic neuron located in PNS
104
postganglionic (unmyelinated) motor neuron of the autonomic nervous system
terminates on the effector organ
105
sympathetic nervous system
fight or flight
receives innervation from THORACOLUMBAR DIVISION (T1-L2)
releases epi (vasodialtes) and norepi (constricts)
106
effects of lesions interrupting sympathetic fibers
blood vessel dilation (skin gets warm/red), lack of seating in involved area, constricted pupil on side of lesion, paralysis of arrector pili muscles so "good bumps" don't happen when pt is cold
107
what is a lesion in the sympathetic fibers?
damage
108
horner's syndrome
injury to preganglionic sympathetic trunk or postganglionic sympathetic neurons of cervical ganglion
with these patients you'll see ipsilateral pupil constriction (occurring on the same side), sunken Ipsiolateral eyeball, ptosis of ipsilateral eye (droooping), no sweating on ipsilateral side of face
109
neuroreceptors of the sympathetic nervous system
a-adrenergic and b-adrenergic receptors (alpha 1 is most common)
110
sympathetic postganglionic nerve fibers release which neurotransmitter?
norepinephrine
111
parasympathetic nervous system
rest and digest
conserves and restores energy
receives innervation from CRANIOSACRAL DIVISION (cell bodies in CRANIAL NERVE NUCLEI and SACRAL REGION OF SPINAL CORD)
112
cell bodies of the parasympathetic nervous system are located in which region of the spinal cord?
cranial and sacral
113
neuroreceptors of the parasympathetic nervous system
cholinergic receptors (nicotinic type 1 and muscarinic)
nicotini= **muscle contraction at NMJ**
can be found on cells of ADRENAL MEDULLA
114
parasaympathetic effect on body parts
pupil-constriction
heart- slows heartbeat
airway- constricts the bronchial tubules
liver- stimulates bile release
blood vessels- constriction
digestive system- stimulates activity
uterus- relaxation
urinary system- increases the urinary output
cranial part of spinal cord is responsible for pupil, heart, airways, liver, blood vessels, and digestive system
sacral part of spinal cord is responsible for uterus and urinary system
115
sympathetic effect on body parts
pupil- dilates
heart- increases heartbeat
airway- dilates the bronchial tubules
sweat glands- stimulates activation
liver- increases the rate of glycogen to glucose
digestive system- decreases activity
adrenal glands- stimulates the production of adrenaline
uterus- vaginal contraction
urinary system- relaxes bladder
sympathetic ganglion in cervical part of spinal cord- pupil
sympathetic ganglion in thoracic part of spinal cord- heart, airways, sweat glands, liver, digestive system
sympathetic ganglion in lumbar part of spinal cord- adrenal glands, uterus, urinary system
116
parasympathetic nerve roots
cranial nerves III, VII, IX, X
sacral nerves 2, 3, 4
117
sympathetic nerve roots
thoracic nerves 1-12
lumbar nerves 1 and 2
118
craniosacral division of autonomic nervous system
parasympathetic
119
thoracolumbar division of autonomic nervous system
sympathetic
120
sensory pathways
pain-temp (spinothalamic tract)
proprioception and vibratory sense in posterior column
vague light touch (anterior spinothalamic tract)
121
pathway for PAIN and TEMP
enters spinal cord then **immediately crosses over cord**
then travels to thalamus on opposite side where it enters
122
pathways for PROPRIOCEPTION and VIBRATORY SENSE
**stays on the same side of the spinal cord until it reaches the BRAINSTEM**
123
lesion of SPINOTHALAMIC TRACT
loss of PAIN-TEMP CONTRALATERALLY BELOW level of lesion (because of immediate cross over in spinal cord)
124
lesion in POSTERIOR COLUMN
**ipsilateral loss/decreases in stereogenesis, vibratory sense, proprioception** in conscious pts (because there is NO cross over until the level of the brainstem)
posterior=proprioception!!!=iPsilateral
125
LIGHT TOUCH is carried where?
in BOTH tracts so it's SPARED in unilateral spinal cord lesions (because there are alternate routes)
126
somatic-superficial pain
comes from connective tissue, muscle, bone, and skin
pain is sharp/well localized with A delta fibers
pain is dull aching, and poorly localized with C fibers
127
visceral-internal pain
transmitted via sympathetic afferents
poorly localized, dull
fewer nociceptors
128
referred pain
pain is somewhere other than its origin
area of referred pain is supplied by same spinal segment as actual site (ex: MI)
129
chronic pain
can be persistent/intermittent and sudden/gradual lasting 3-6 months or more
can lead to behavior/psychological changes(unlike acute)
conditions include myofascial pain syndromes, chronic post op pain, low back pain, chronic pain with cancer
130
neuropathic pain
d/t trauma or disease of PNS/CNS
usually chronic
131
chronic neuropathic pain groups
peripheral and central
132
peripheral chronic neuropathic pain
injured nerves are now hyper excitable
causes are trauma, DM, ETOH, CA, HIV
133
central chronic neuropathic pain
d/t lesion or dysfunction in brain/spinal cord
causes are brain/spinal cord trauma, vascular lesions, MS, post-herpetic neuralgia, phantom limb pain, reflex sympathetic dystrophy
134
s/s of neuropathic pain
paroxysaml with herpesthesia and paresthesia (pins and needles), burning, shooting, stabbling
"gnawing" and miserable
135
deafferentation
neuropathies that are d/t lesions in PNS
136
hemiagnosia
paralysis and hypersensitivity on 1 half of body
137
phantom limb
pain felt in amputated limb after stump has healed
type of neuropathy
138
complex regional neuropathic pain
1-2 weeks
after injury (fracture without an identifiable nerve injury) OR injury to brachial plexus or median, sciatic, or other peripheral nerves
139
radiculopathy
a patient presents with a herniated lumbar disc and they are complaining of pain in their right leg
