nervous system & spinal cord Flashcards
1
Q
what is the main goal of the nervous system
A
to maintain homeostasis
2
Q
what are the 2 divisions of the NS
A
central NS and peripheral NS
3
Q
what is the CNS
A
brain and spinal cord
integration and command centre
4
Q
what are the 3 divisions of the PNS
A
somatic NS
autonomic NS
enteric NS
5
Q
afferent is ___
A
sensory
6
Q
efferent is ___
A
motor
7
Q
how many nerves are a part of the PNS
A
12 cranial and 31 spinal
8
Q
which is the “voluntary” NS
A
somatic
9
Q
SNS motor neurons conduct impulses from CNS to ___ ONLY
A
skeletal muscles
10
Q
what are the special senses
A
a part of the somatic NS
vision, hearing, smell, taste, and equilibrium
11
Q
SNS does what type of movements
A
voluntary
12
Q
the ANS transmits from ___ to CNS
A
visceral organs
(lungs, heart, kidneys)
13
Q
the ANs is (vol/invol)
A
involuntary
14
Q
what are the 2 divisions of ANS
A
sympathetic and parasympathetic
15
Q
sympathetic division is what response
A
fight or flight
16
Q
parasymp division is what response
A
rest and digest
17
Q
what do sensory neurons monitor in the ENS
A
chemical changes
stretching walls of GI tract
18
Q
the ENS motor neurons control what
(voluntary/involuntary)
A
contractions and secretions
involuntary
19
Q
what are the 3 functions of the nervous system
A
sensory fn
integration fn
motor fn
20
Q
what is the sensory function
A
monitor changes inside and outside of the body
retrieve stimulus and sensory input
21
Q
what is the integration function
A
interpret the sensory info
make decisions
22
Q
what is the motor function
A
generate a response
activate effectors
23
Q
what are the 2 histology types of nervous tissue
A
neurons and neuroglia
24
Q
can axons in the (PNS) regenerate
A
yes, but very slowly
25
can neurons in the CNS regenerate?
no
26
what do neurons do
generate and propagate nerve impulses
27
how much more plentiful are neuroglia than neurons
25x more
28
can neuroglia transmit nerve impulses
no
29
what do neuroglia do
support, nourish, and protect the neurons
30
what is a key point of neuroglia
they divide throughout their entire life
31
do neuroglia have anything to do with the actual nerve impulses
no!!
32
what are the 3 parts of neurons
cell body
dendrites
axon
33
what does the cell body of the neurons contain
the nucleus
34
what do the neurons dendrites do
receiving and input part
35
what do neural axons do
propagates nerve impulses to other neuron, muscle, or gland
36
what is the axon hillock
where the cell body meets the axon
37
where are action potentials initiated
at the axon hillock
38
what are the 3 functional classifications of neurons
sensory (afferent)
motor (efferent)
interneurons
39
90% of neurons are ___
interneurons (the decision makers)
40
where are interneurons located
CNS
41
sensory neurons do what
conduct nerve impulses TOWARDS the CNS
42
motor neurons do what
carry nerve impulses AWAY from the CNS
43
what are the 6 types of neuroglia
astrocytes
oligodendrocytes
microglia
ependymal cells
Schwann cells
satellite cells
44
which neuroglia are in the CNS
astrocytes
oligodendrocytes
microglia
ependymal cells
45
which neuroglia are in the PNS
schwann cells
satellite cells
PS (peripherals start with p)
46
what do satellite cells do
surround the neuron cell bodies in the ganglia
47
what do Schwann cells do
form the myelin sheath
nerve fiber regeneration
48
what does the myelin sheath do
protect and electrically insulate the fiber
49
what forms the myelin sheath in the CNS
oligodendrocytes
50
what forms the myelin sheath in the PNS
scwann cells
51
what is multiple sclerosis
demyelination preventing normal travel of impulses
52
what does the myelin sheaths allow the electrical impulse to do
jump from node to node
53
whare are the collections of cell bodies called in the PNS and CNS, respectively
PNS - ganglion
CNS - nucleus
54
what are collections of axonscalled in the PNS and CNS, respectively
PNS - nerve
CNS - tract
55
what is gray matter (6)
anything decision making
neuronal cell bodies, dendrites, UNmyelinated axons, axon terminals, neuroglia
56
why is it gray matter
no myelin sheath!!
Nissl bodies in the cell body are gray
57
what is white matter
myelinated axons
for high speed travel
58
what is a resting membrane potential
a building of neg charges inside membrane
a buildup of pos charges outside memrane
59
what is a typical resting membrane potential (give the charge)
-70 mV
60
why are cells negative when resting potentials
cells are more permeable to potassium than to sodium
61
what maintains the potential difference
sodium-potassium pump
62
what are the 4 Ion channel types
1. leak channels
2. chemically-gated
3. mechanically-gated
voltage-gated
63
what are leaks channels
THE WHOLE REASON FOR A RESTING MEMBRANE POTENTIAL
64
what are ligand-gated channels
AKA chemically gated
gates open and close due to chemical stimulus
65
what are mechanically-gated channels
gates open or close due too vibrations, stretching, or pressure
66
what are voltage-gated channels
responsible for conduction of action potentials across the axon
67
what are the 2 types of electrical signals in neurons
graded poentials
action potentials
68
what is a graded potential
small deviations from resting membrane potential (more or less polarized)
69
how can a graded potential start an action potential
mechanically gated channel
chemically gated channel
70
where do graded potentials mainly occur
dendrites and cell bodies
71
how far to graded potentials travel
very localized - only short distances
72
what is the most common stimulus for action potentials
graded potentials
72
what is propagation
action potentials' ability to travel long dostances without losing the strength of the signal
73
where is the trigger zone for the action potential
axon hillock
74
what needs to be reached for the action potential to occur
threshold level
75
describe the all or nothing principle
According to the all-or-nothing principle, if a
stimulus reaches threshold, the action potential
is always the same.
– A stronger stimulus will not cause a larger impulse
76
will a stronger signal create a bigger impulse?
no. not size, just frequency
77
what is the synapse
The site of communication between 2 neurons
or between a neuron and an effector cell
78
what are the 2 synapse types
chemical and electrical
79
what makes up the white matter in the spinal cord
oligodendrocytes
80
how is white matter divided
into columns
81
what are the 3 white matter columns
dorsal column
lateral column
ventral column
82
white matter columns contain:
tracts
83
what are tracts
bundles of axons in the CNS
84
sensory tracts are (ascending/descending)
motor tracts are (ascending/descending)
sensory ascending
motor descending
85
the posterior column tracts are (ascending/descending)
ascending (only sensory)
86
the lateral and anterior columns' tracts are (ascending/descending)
both!!
87
what is the hole between the anterior and posterior gray commissures
central canal
88
what is a plexus
a network
89
what do spinal nerves branch into, and when
rami, after passing through the intervertebral foramina
90
which are the only nerves that go directly to the area they supply
except for the intercostal nerves T2-T12
91
name the 5 network types
cervical
brachial
lumbar
sacral
coccygeal
92
what level is the cervical plexus
C1 to C5
93
where do the phrenic nerves arise from
C3, C4, C5
94
what do the C3-C5 phrenic nerves do
supply the motor neurons to the diaphragm
95
what are the 3 muscles associated with the cervical plexus
sternocleidomastoid
erector spinae
levator scapulae
96
what is referred pain distribution
sensory stimuli from diaphragm is often interpreted as pain over shoulder and lower neck
97
what rami form the brachial plexus
C5-C8 and T1
98
what are the division of the brachial plexus
roots, trunks, divisiona, cords, nerves
99
what 6 major nerves are supplied by the brachial plexus
musculocutaneous
axillary
radial
median
ulnar
long thoracic
100
what does wrist drop indicate
damage to radial nerve
101
what does median nerve palsy indicate
median nerve damage
102
what does ulnar nerve palsy indicate
damage to the ulnar nerve
103
what does winging of the right scapula indicate
damage to the long thoracic nerve
104
what is shown here?
median nerve palsy
105
what is shown here?
wrist drop
106
what is shown here?
ulnar nerve palsy
107
what is shown here?
winging of the scapula
108
what roots supply the lumbar plexus
L1 to L4 (NOT 5)
109
what does the lumbar plexus supply
anterolateral abdominal wall
external genitals
the anterior part of our lower limbs
110
what nerves are involved with the lumbar plexus
femoral
obturator
saphenous
111
what roots supply the sacral plexus
L4 to S4
112
what areas are involved with the sacral plexus
buttock, perineum, posterior of lower limbs
113
what is the biggest nerve in the body
the sciatic nerve
114
the sciatic nerve branches into what, where
tibial and common fibular nerves, at the knee
115
what is a dermatome
an area of skin supplied by a single spinal nerve
116
what are dermatomes useful for
to determine neurologic levels
117
name 2 refelxes
patellar and plantar
118
what is the integration centre for some reflexes
the spinal cord
119
what is a babinsky sign
toes fan, great toe moves outwards (instead of flexing)
normal for infants, not adults
120
where do the spinal nerves exit
through the intervertebral foramina
121
what is the lumbar puncture level and why?
L3/L4
low enough to clear the spinal cord, but S1/S2 has no joint space
122
where does the spinal cord end
L1/L2
123
why lumbar puncture at L3/L4 and not L4/L5
less tissue in the joint space
124
what is the main function of grey matter
decision making!!!!
125
what is the effect of damage to the anterior spinal cord
messed up nerve impulses
contraction of skeletal muscles
126
the spinal cord continues from what to what?
medulla oblongata (through foramen magnum)
to conus medullaris
in disc space at L1/L2
127
what is at C4/T1 (spinal cord)
the cervical enlargement
128
what spinal landmark is at T9-T12
lumbar enlargement
129
what anchirs the spinal cord to the coccyx
filum terminale
130
what is the filum terminale
arises from conus medullaris
attaches cord to coccyx
131
what does the spinal cord contain
the major reflex center
132
how is the spinal cord protected
cord is surrounded by the vertebra
3 layer meninges
CSF is a shock absorber
133
the spinal meninges extend to what level
S2
134
what are the 3 meninge layers
pia mater
arachnoid mater
dura mater
135
what are the 3 meninge spaces
epidural space
subdural space
subarachnoid space
136
which meninge space contains CSF
subarachnoid space
137
the epidural space is between what
the dura mater and vertebra
138
the subdural space is between what
dura and arachnoid maters
139
the subarachnoid space is between what
the arachnoid and pis maters
140
how many spinal nerves are there
31 pairs
141
what are the spinal nerve divisions and their numbers
cervical - 8
thoracic - 12
lumbar - 5
sacral - 5
coccygeal - 1
142
what is caudad equina
Cauda equina syndrome is a rare and serious condition that occurs when the nerves at the end of the spinal cord are compressed
143
spinal roots are formed by ______
2 roots from the spinal cord:
posterior (dorsal, sensory)
anterior (ventral, motor)
144
ALL spinal nerves are: S/M/M
mixed!!
145
the dorsal root contains what only
axons of sensory neurons
146
dorsal root ganglion contain what
cell bodies of sensory neurons
147
what physical divisions are in the white matter of the internal spinal cord
anterior median fissure
posterior median sulcus
148
what are the parts of the gray matter in the spinal cord
dorsal horn
lateral horn
ventral horn
commissure
149
what is in the dorsal horn of the spinal cord
incoming sensory neurons
cell bodies and UNmyelinated axons of interneurons
150
what is in the ventral horn
somatic motor nuclei
(clusters of somatic cell bodies)
nerve impulses for contraction of skeletal muscles
151
the lateral Horns prevent only in which segments of the spinal cord
T and L segments
152
what is in the lateral Horns of the spinal cord
autonomic and enteric motor nuclei
153
how to best Dems C-spine interverteral foramina
45 degrees oblique
(bilateral views)
154
how to best Dems T-spine interverteral foramina
45 degrees PO
155
how to best Dems L-spine interverteral foramina
PO 45 degree
156
how to best Dems sacrum interverteral foramina
AP???
