Ch. 12: The Spine Flashcards
(182 cards)
1
Q
what receives sensory input from receptors?
A
both brain and spinal cord
2
Q
both the brain and spinal cord contain ___ centers
A
reflex
3
Q
both the brain and spinal cord send motor output to ___
A
effectors
4
Q
what is a reflex?
A
rapid, autonomic response triggered by small stimuli
5
Q
spinal reflexes are controlled by
A
the spinal cord
6
Q
spinal reflexes function without input from the
A
brain
7
Q
a CS of the spinal cord has outer __ matter and inner __ matter
A
white; grey
8
Q
the adult spinal cord is __ cm
A
45
9
Q
the spinal cord ends at
A
L1-L2
10
Q
the spinal cord has how many nerves?
A
31
11
Q
how many cervical nerves?
A
8
12
Q
how many thoracic nerves?
A
12
13
Q
how many lumbar nerves?
A
5
14
Q
how many sacral nerves?
A
5
15
Q
how many coccygeal nerves?
A
1
16
Q
structure and location of conus medullaris
A
cone-shaped end of spinal cord at L1-L2
17
Q
what is the Filum terminale? Function?
A
area from tip of conus medullaris to S2. Provides longitudinal support to spinal cord
18
Q
what is the Cauda equina (horse tail)?
A
the extended anterior and posterior roots of L2-S5 and the filum terminale
19
Q
___ pairs of spinal nerves arise from __ spinal cord segments
A
31; 31
20
Q
names of spinal nerves are designated by __ and __
A
region and number
21
Q
C1 nerves runs ___ the 1st cervical vertebra
A
above
22
Q
all vertebrae other than C1 are named for the vertebra ___ (above/below)
A
above
23
Q
white matter is made of
A
myelinated and some unmyelinated axons
24
Q
gray matter is made of (3)
A
neuron cell bodies, neuroglia, unmyelinated axons
25
the central canal contains
CSF
26
do spinal nerves have axons of sensory or motor neurons?
both!
27
anterior root contains
axons of motor nuerons
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posterior root contains
axons of sensory neurons
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posterior root ganglion contains
cell bodies of sensory neurons in posterior root
30
how many spinal meninges are there? What are they?
1. dura matter
2. arachnoid matter
4. pia matter
31
in general, what are spinal meninges?
specialized membranes surrounding the spinal cord and connected to cranial meninges
32
what are the functions of the meninges?
1. stability
2. shock absorption
3. carry blood supply (O2, nutrients, waste)
33
structure of dura matter
tough, dense collagen fibers running lengthwise to the spinal cord
34
structure of arachnoid matter
arachnoid membrane of simple squamous and subarachnoid space between AM and pia matter
35
structure of pia matter
meshwork of elastic and collagen, anchored to neural tissue
36
the subaracnoid space contains what three things? Funtions of each?
1. arachnoid trabeculae -- collagen and elastic that anchor to pia
2. CSF -- shock absorption, diffusion of gas, nut, etc
3. blood vessels
37
where is the epidural space and what is it made of?
between dura and vertebrae; areolar, blood vessels, adipose
38
what is a lumbar puncture/spinal tap?
taking out sample of CSF
39
Where is needle inserted in lumbar puncture?
into subarachnoid space, lumbar region below conus medullaris
40
why is a spinal tap done below conus medullaris?
to avoid spinal cord and thus reduce risk of damage
41
what are nuclei in grey matter?
functional unit of neuron CB
42
function of sensory nuclei
receive and relay sensory information
43
function of motor nuclei
issue motor commands to effectors
44
gray commissures contain axons that ___
axons that cross from sides to side in the spinal cord
45
where are gray commissure located?
posterior and anterior to the central canal
46
white matter is organized in __, which are bundles of __ in CNS
tracts; axons
47
ascending tracts carry __ information in __ columns
sensory; posterior
48
descending tracts carry __ commands in __ columns
motor commands; anterior columns
49
what are the 3 connective tissue layers surrounding the spinal nerves?
1. epineurium
2. perineurium
3. endoneurium
50
what is the epineurium?
outermost layer; dense network of collagen fibers
51
what is the perineurium?
middle layer; separates nerve into fascicles
52
what are nerve fascicles?
bundles of axons
53
what is the endoneurium
innermost layer; surrounds individual axons
54
arteris and veins go through the ___ and branch in the ___, and capillaries enter the ___
epineurium, perineurium, endoneurium
55
each spinal nerve divides into two ___
rami
56
posterior ramus is responsible for __ (3)
muscles, joints, skin of back
57
anterior ramus is responsible for __ (3)
lateral and anterior trunk, limbs
58
which spinal nerves carry out motor output of sympathetic ANS? (Fight/Flight)
T1-L2
59
what is a dermatome?
specific bilateral area of skin supplied by a pair of spinal nerves
60
what nerve usually lacks a sensory branch? What does it supply when present?
C1; scalp with C2 and 3
61
the face is monitored by which nerve?
CN V
62
are dermatome boundaries distinct and absolute?
no, there is overlap
63
which virus causes shingles and chickenpox?
vericella-zoster (herpes)
64
the herpes VZV virus acts on ____ and ____
neurons in posterior roots and sensory ganglia
65
what causes shingles?
it lies dormant in anyone who has had chickenpox and trigger is unknown
66
sensory information is collected from ___ and delivered to ___ in the spinal cord
periphery; sensory nuclei in spinal cord
67
the sympathetic nerve collects sensory information from __
visceral organs
68
the anterior ramus collects sensory information from __ (3)
ventrolateral body surface, body wall, and limbs
69
the posterior ramus collects sensory information from __
skin and skeletal muscles of the back
70
the posterior root carries information from __
spinal cord
71
the anterior root contains axons of the __ and __
somatic, visceral motor neurons
72
the spinal nerve forms at junction of __ and ___
anterior and posterior roots
73
the posterior ramus carries contains ___ that carry info to _-
somatic/visceral motor fibers to skin/skeletal muscles of back
74
the anterior ramus carries information to the __, __, and __
ventrolateral body surface, body wall, limbs
75
what is the white ramus communicans?
short branch with preganglionic visceral motor fibers to sympathetic ganglia
76
what is the grey ramus communicans?
postsynaptic fibers to glands/ smooth muscle
77
sympathetic nerve carries ____ fibers to __
pre/postsynaptic ; thorarcic cavity
78
what is a nerve plexus?
complex, interwoven nerve network
79
when is the nerve plexus formed?
during development
80
how is are nerve plexuses made?
anterior rami of adjacent spinal nerves blend fibers to form plexuses
81
what are the 4 major plexuses?
1. cervical plexus
2. brachial plexus
3. lumbar plexus
4. sacral plexus
82
the cervical plexus supplies the
neck and diaphragm
83
the brachial plexus supplies the
pectoral girdle, upper limb
84
the sacral plexus supplies the
pelvic girdle, lower limb
85
the cervical plexus is formed by the
anterior rami of C1-C5
86
the phrenic nerve is formed by
C3 - C5
87
the phrenic nerve supplies entire nerve supply to
the diaphragm
88
most nerves of brachial plexus come off ___ and a few originate at the ___
cords; trunks
89
what are the 5 major brachial plexus nerves?
1. musculocutaneous nerve
2. median nerve
3. axillary nerve
4. radial nerve
90
why is cutaneous nerve distribution to wrist and hand clinically important?
nerve damage can be precisely localized by testing sensory function of the hand
91
the lumbar and sacral plexuses are formed from
lumbar and sacral segments of spinal cord
92
the lumbar plexus is formed from the
spinal nerves T12-L4
93
what is the lumbosacral trunk?
L4 branches contribute to sacral plexus
94
the sacral plexus is formed by the
spinal nerves L4-S4
95
what is the sciatic nerve? To which plexus does it belong?
largest, longest nerve in the body. Sacral plexus
96
what are the 4 nerves supplying the foot and ankle?
1. saphenous
2. sural
3. common fibular
4. tibial
97
what are neural pools?
functional groups of interconnected neurons
98
what 2 things may neural pools include?
1. neurons of various parts of the brain
| 2. neurons of specific part of CNS
99
what element of a neural pool reflects its function?
pattern of interaction
100
the most complex circuits of neural pools are found in the
brain
101
the simplest circuits of neural pools are found in the
PNS and spinal cord
102
the simple circuits of neural pools control__
autonomic responses and reflexes
103
what are the 5 common patterns of neural interaction?
1. divergence
2. parallel processing
3. seriel processing
4. reverberation
5. convergence
104
describe divergence
spread information from one neuron/neural pool to several
105
what does divergence allow for?
broad distribution of specific input
106
describe convergence
several neurons meet on the same postsynaptic neuron
107
why can motor neurons experience both conscious and unconscious control?
convergent neural circuits
108
what is an example of convergence?
voluntary adjustment to breathing
109
describe parallel processing
several neurons processing the same information simultaneously
110
what has to happen before parallel processing can occur?
divergence
111
describe serial processing
transfer of information in steps (1 neuron/pool to the next)
112
give an example of serial processing
information moving from one part of the brain to the next
113
describe reverberation
a collateral braches reaches back to the source of the impulse and stimulates it to continue
114
reverberation involves what type of loop?
positive feedback
115
reverberation continues until
synaptic fatigue, of inhibitor
116
reflexes preserve ___ through rapid ___ to organs/systems
homeostasis; adjustments
117
what are the 5 parts of a reflex arc?
1. stimulation of a receptor
2. activation of sensory neuron
3. information processing in CNS
4. activation of motor neuron
5. response of peripheral effector
118
a receptor can be ___ or ___. What do they detect?
specialized cell, or dendrites of sensory neuron. Chemical, physical changes
119
in the 2nd step of reflex arc, the stimulation of dendrites causes ___, which induces action potentials in sensory neurons. The signal then enters the spinal cord through __
graded potential; sensory neurons; posterior root
120
in the 3rd step of reflex arc, sensory neurons release __ the induces a ___ postsynaptic potential at the ___
neurotransmitter; excitatory; interneuron
121
what two things do interneurons do once given an excitatory potential?
create action potentials of motor neurons and send out pain to CNS
122
motor neurons relese __ that stimulates __ to respond
neurotransmitters; effectors
123
what 4 things classify reflexes?
1. development (innate/acquired)
2. nature of response (somatic/visceral)
3. complexity of circuit (mono/poly synaptic)
4. processing site (Brain or spine)
124
what are innate reflexes?
basic neural impulses youve had since birth
125
innate reflexes appear in a predictable sequence from __ to __
simplest to most complex
126
what are acquired reflexes?
rapid automatic learned motor responses that enhance with repetition
127
what are somatic reflexes?
involuntary control of skeletal muscles
128
what is an example of somatic reflex?
withdrawal reflex
129
what are visceral reflexes?
control involuntary effectors (Smooth, cardiac, glands, glands, adipose tissue)
130
monosynaptic reflexes involves sensory neuron synapses ___ with motor neurons
directly
131
polysynaptic reflexes involve sensory neuron synapses ___ with motor neuron
indirectly
132
which synaptic reflexes have interneurons?
polysynaptic
133
are mono or polysynaptic reflexes faster?
monosynaptic
134
processing of the spinal reflexes occurs in the
spinal cord
135
intersegmental reflexes involve ___ of spinal cord
multiple segments
136
processing of cranial reflexes occurs in the
brain
137
what is the best know monosynaptic reflex?
stretch reflex
138
the stretch reflex automatically regulates __
skeletal muscle length
139
what stimulus activated stretch reflex?
increasing muscle length
140
what is the response of the stretch reflex?
to contract muscle
141
give an example of the stretch response?
patellar reflex
142
____ act as the sensory receptors for stretch reflex
muscle spindles
143
muscle spindles are made of
intrafusal muscle fibers
144
what are intrafusal muscle fibers?
bundles of small, specialized skeletal muscle fibers
145
intrafusal muscle fibers are supplied by __ neurons
both sensory and motor
146
muscle spindles are surrounded by muscle fibers that maintain ___ and can __ the whole muscle
muscle tone; contract
147
the ___ motor neuron innervates each muscle spindle
gamma
148
gamma motor neurons alter __ in intrafusal fibers; allowing CNS to increase/decrease ___
tension; muscle tone
149
stretched length stimulates ___ from __
more frequent action potentials from sensory neuron
150
compressed length stimulates __
inhibition of sensory neuron ; motor neuron not stimulated, decrease muscle tone
151
postural reflexes function
help maintain normal, upright position
152
balance is maintained by many muscle groups doing what?
working in opposition
153
leaning forward stimulates stretch receptors in __ which __
calf muscles; contract to pull you back
154
postural adjustments are usually
unconscious
155
strongest withdrawal reflexes are stimulated by
painful stimuli
156
withdrawal reflexes can be stimulated by
stimulus from touch or pressure
157
withdrawal reflexes are versatile because
sensory neurons activate many pools of interneurons
158
distribution and strength of response depend on
intensity and location of stimulus
159
flexor reflex is a type of __reflex
withdrawal
160
flexor reflex affects
muscle of a limb
161
give an example of flexor reflex
pain stimulus of grabbing hot pan
162
sensory neurons in the flexor reflex activate __ in the spinal cord
interneurons
163
interneurons in the flexor reflex stimulate motor neurons in __ resulting in ___ and ___
anterior gray horns; contraction of flexor muscles and reciprocal inhibition
164
what is reciprocal inhibition?
keeps extensors relaxed (blocks opposition)
165
stretch and withdrawal reflexes use ___ reflex arcs; which means sensory and motor are on __ side of the body
ipsilateral; the same
166
crossed extensor reflexes involve __- reflex arcs
contralateral
167
contralateral reflexes involve
an additional motor response occurs on the opposite side of the stimulus
168
crossed extensor reflexes are coordinated with __
flexor reflexes
169
in crossed extensor reflexes: flexion of affected side is accompanied by __
extension on the opposite side
170
give an example of crossed extensor reflexes
step on something sharp, before flexor lifts hurt foot, crossed extensor reflex straightens opposite limb to hold the weight
171
what reflexes control autonomic actions involved in complex movements (walking and running)
polysynaptic reflexes
172
what are the five properties of the polysynaptic reflexes?
1. involve pools of interneurons which may be excitatory / inhibitory
2. involve multiple spinal segments that may activate muscle groups in many areas
3. involve reciprocal inhibition that coordinates movement and reduces resistance
4. have reverberating circuits that prolong motor response
173
the ____ can facilitate or inhibit motor neurons / interneurons involved in a reflex
brain
174
facilitation is called
reinforcement
175
___ maneuver facilitates patellar reflex
Jendrassik
176
biceps, triceps, ankle-jerk reflexes are ___ reflexes that are each controlled by specific ____
stretch ; spinal segemnts
177
the babinski reflex involves
stroking the lateral side of sole triggers extension of hallux and spreading of toes
178
the babinski reflex occurs due to
lack of inhibition by descending moror fibers
179
the babinski response disappears as
descending pathways develop
180
what is the plantar reflex?
in adults, stroking bottom lateral side of foot causes toes to curl
181
what is the abdominal reflex?
stroking of skin produces reflexive twitch an ab muscles; moving navel towards stimulus
182
the abdominal reflex depends on facilitation of
descending tracts
