Intro to Nervous System Flashcards
(93 cards)
1
Q
What does the CNS consist of?
A
brain and spinal cord
2
Q
what does PNS consist of?
A
cranial and spinal nerves
3
Q
cranial nerves
A
12 pairs
4
Q
spinal nerves
A
31 pairs
5
Q
afferent
A
away from skin; toward spinal cord
6
Q
what kind of nerves are afferent nerves?
A
somatic (from body), and visceral (lungs/heart/etc)
7
Q
efferent
A
to the muscles; away from spinal cord
8
Q
what kind of nerves are efferent nerves?
A
somatic (skeletal muscle), visceral–aka autonomic (sympathetic/parasympathetic nerves)
9
Q
glia
A
non-neuronal cells that provide structure, get rid of NTs, lyse debris, etc. (like an astrocyte, Schwann cells, etc.)
10
Q
unipolar neuron
A
has a cell body with a single process (dendrite and axon off same extension)
11
Q
bipolar neuron
A
cell body has axon on one side and dendrites on another; two processes
12
Q
pseudounipolar neuron
A
has a single process out of cell body with bifurcated extensions (central and peripheral processes) perpendicular to primary process
13
Q
multipolar neuron
A
has multiple processes extending from cell body; ex) motor neuron, pyramidal cell of hippocampus, Purkinje cell of cerebellum
14
Q
white matter
A
neuron processes (extensions of axons/dendrites)
15
Q
gray matter
A
cell bodies
16
Q
where is the white matter in the brain
A
in the middle of the brain
17
Q
where is the gray matter in the brain
A
surrounding the brain (cortex) and in the very middle of the brain (nuclei)
18
Q
where is the white matter in the spinal cord?
A
surrounding the spinal cord
19
Q
where is the gray matter in the spinal cord?
A
in the ventral, lateral and dorsal horns (middle) and in the ganglia
20
Q
where is the spinal cord enlarged?
A
at the cervical and lumbar regions
21
Q
where does the spinal nerve of a given spinal cord segment exit the vertebral canal?
A
through the intervertebal foramen
22
Q
which spinal nerves emerge above their corresponding vertebra?
A
cervical spinal nerves
23
Q
where does the C8 spinal nerve emerge?
A
above the T1 vertebra
24
Q
where does the C2 spinal nerve emerge?
A
above the C2 vertebra
25
which spinal nerves emerge BELOW their corresponding vertebra
thoracic, lumbar and sacral spinal nerves
26
where does the L4 spinal nerve emerge?
about L5/below L4
27
where is C1 spinal nerve?
between occipital bone and atlas of C1
28
where between which vertebrae should one get CSF from an LP?
between L3/L4 (below L2, where spinal cord ends)
29
what is the caudal end of the spinal cord called?
the conus medullaris
30
where does the spinal cord end?
L1/L2
31
caudal equina
spinal roots of lower spinal cord segments (surrounded by the pia, arachnoid and dura maters)
32
ramus
branch of spinal nerves
33
plexuses
branches of rami
34
anterior/ventral root
motor neurons
35
posterior/dorsal root
sensory neurons
36
ganglia
cell bodies associated with dorsal roots (sensory)
37
spinal nerve
segment of BOTH motor and sensory neurons (after anterior/posterior rootlets of neurons from ventral/dorsal horns of spinal cord)
38
What are the components of spinal nerves?
dorsal/ventral rami (sensory/motor), white communicating ramus, gray communicating ramus
39
white communicating ramus
connects spinal cord to SYMPATHETIC CHAIN at T1 to L2
40
gray communicating ramus
connects SYMPATHETIC CHAIN to spinal nerves at all levels
41
sympathetic trunk
aka sympathetic ganglia/chain ganglia/paravertebral bodies are enlarged clusters of cell bodies lining the spinal cord on either side laterally
42
where is the intercostal nerves?
between ribs
43
what is the function of the somatic sensory pathway?
transmit info regarding pain, temperature, touch, pressure, vibration and proprioception to CNS (sensory neurons!!)
44
where are the neuron cell bodies of the somatic sensory pathway located?
in the dorsal root ganglia (sympathetic trunks)
45
what detects a stimulus in the somatic sensory pathway?
peripheral receptor
46
what transmits info from peripheral process in spinal nerve to central process in dorsal root?
pseudounipolar sensory neuron
47
where does the central process terminate in the spinal cord in the somatic sensory pathway?
in the lateral horn of gray matter (in the center of the spinal cord)
48
dermatome
area of skin innervated by the sensory fibers of a single spinal nerve
49
dermatome of thumb
C6
50
dermatome of little finger
C8
51
dermatome of nipple
T4
52
dermatome of umbilicus
T10
53
dermatome of anterior and inner surface of lower limb
L1-L4
54
dermatome of perineum
S2. S3. S4
55
Supposed you are the ER doctor and a teenage boy comes to you with a T3 vertebra injured, where would his sensation be lost?
in his chest
56
what is the function of the somatic motor pathway?
transmit signals from the spinal cord causing involuntary OR voluntary contraction of skeletal muscles
57
what are the two resulting movement of skeletal muscles of the somatic motor pathway?
reflexive or purposeful movement of skeleton
58
what kind of cell body is located in the ventral horn of the spinal cord?
multipolar neuron cell body
59
where does the axon of a somatic motor neuron extend?
from the ventral horn through the ventral root (ramus) into the spinal nerve
60
where does the axon of a somatic motor neuron end?
in skeletal muscle/target organ (signals contraction)
61
clinical examples of somatic motor pathway:
testing reflexes in a clinical exam; finding paralysis in patient
62
What is the function of the visceral sensory pathway?
transmit signals from internal organs (viscera) to the brain
63
where is the neuron cell body (visceral sensory pathway) located?
in the DRGs
64
in the visceral sensory pathway, what detects the stimulus?
peripheral receptors
65
what kind of neuron transmits the signal from the peripheral process in spinal nerve to the central process in dorsal root ganglia?
pseudounipolar sensory neuron
66
where does the central process of a nerve terminate in the visceral sensory pathway?
in the dorsal horn (gray matter) in the spinal cord
67
which type of nervous pathway helps to monitor homeostasis?
visceral sensory pathway
68
what is referred pain and from which nervous pathway does it come?
it is when there are two nerve signals from the periphery/viscera that both synapse at one dorsal horn projection neuron, which then goes to the thalamus; when only one "fire", brain assumes periphery (somatic-->skin), but when both fire at once, it assumes visceral (heart); if only heart is firing, your brain might feel pain in the skin; comes from visceral somatic pathway
69
what is the function of the visceral motor pathway?
transmit signals from CNS causing involuntary contraction of cardiac muscle, smooth muscle or gland secretion
70
what kind of neuron cell body is located in interomediolateral column of spinal cord or within nuclei of brainstem (visceral motor pathway)?
multipolar neuron cell body
71
where is the interomediolateral column of the spinal cord?
lateral horn at T1 to L2
72
where do the processes go from the spinal cord in the visceral motor pathway?
from the ventral horn to the ventral root (ramus) to the spinal nerve
73
where does the neuron synapse with a second one in the visceral motor pathway?
in an autonomic ganglion (location varies)
74
where does the axon of the second neuron terminate in the visceral motor pathway?
in the target organ, signaling a response
75
what is another name for the visceral motor pathway?
autonomic nervous system
76
what is the function of the AUTONOMIC nervous system
homeostasis (rest/digest), emergency (fight/flight) and reproduction
77
what are the target organs for the autonomic nervous system?
cardiac muscle, smooth muscle and glands
78
what are the three divisions of the autonomic nervous system?
sympathetic, parasympathetic and enteric
79
what kind of spinal nerves does the parasympathetic NS involve?
craniosacral outflow
80
what kind of spinal nerves does the sympathetic NS involve?
thoracolumbar (motor) outflow
81
what kind of spinal nerves does the enteric NS involve?
plexuses with GI tract
82
what does each pathway of the autonomic nervous system consist of?
preganglionic neuron, ganglion, and postganglionic neuron
83
what is a ganglion consist of in the autonomic nervous system?
cell body of postganglionic nerve and site of synapse of preganglionic nerve
84
where are the preganglionic neuron cell bodies located in the sympathetic NS?
within T1-L2 levels of spinal cord in interomediolateral cell column (lateral horn)
85
where are the preganglionic neuron cell bodies located in the parasympathetic NS?
within brainstem OR S2-S4 levels of spinal cord in interomediolateral cell column (do NOT form lateral horn)
86
where do the preganglionic neurons exit the CNS in the sympathetic NS?
via ventral roots (horns) and enters sympathetic trunk (ganglia) via WHITE communicating rami levels T1-L2
87
where do the preganglionic neurons exit the CNS in the parasympathetic NS?
via cranial nerves or via ventral roots (horns); pathway varies
88
what are the 3 ways nerves can act in the sympathetic ganglia of Sympathetic NS?
(1) synapse at level of entry (2) synapse at upper/lower levels (3) no synapse and emerge as splanchnic (viscera)
89
where do nerves synapse in parasympathetic NS?
cranial ganglia and plexuses near or in ganglia within target organs (ex. myenteric/submucosal)
90
where are the cell bodies in postganglionic neurons in the sympathetic NS?
cell bodies in para-ganglia or prevertebral ganglia
91
how do axons distribute in the sympathetic NS?
perivascular fibers; gray communicating rami to spinal nerves; thoracic and lumbar splanchnic (viscera); visceral fibers
92
where are the cell bodies in postganglionic neurons in the parasympathetic NS?
in peripheral plexuses or ganglia
93
how do axons distribute in the parasympathetic NS?
cranial or pelvic splanchnic (viscera)
