1.1. Spinal Cord Flashcards
1
Q
Spinal cord is derived from what part of the neural tube?
A
CAUDAL PART of the neural tube
2
Q
SC maintains ____ organization throughout its development until one reaches maturation
A
segmental organization
3
Q
What are the three membranes/meninges of spinal cord?
A
Dura Mater
Arachnoid Mater
Pia Mater
4
Q
What is the weight of the spinal cord?
A
30g
5
Q
How many percent is the adult brain weight?
A
2%
6
Q
What is the lower border of the SC in newborns?
A
L3
7
Q
The SC extends from ____ to _____?
A
foramen magnum to lower border of L1 or L3
8
Q
What is the lower border of the SC in adults?
A
lower border of L1
9
Q
SC is continuous with the medulla oblongata at the ____?
A
Spinomedullary junction
10
Q
What are the three junctions of spinomedullary junction?
A
FEP
Foramen magnum,
Emergence of the 1st cervical nerve and ventral rootlets,
Pyramidal decussation
11
Q
Where is SC located?
A
Subarachnoid space
12
Q
At what cervical level does the subarachnoid space extend to?
A
S2
13
Q
Where is the SC suspended & anchored?
A
Dural sac
14
Q
2 flattened bands of pial tissue that attach to the spinal dura with about 21 teeth
A
Denticulate ligaments
15
Q
How many teeth does denticulate ligaments have?
A
21 teeth
16
Q
A pial filament extending from the conus medullaris (endpoint of the spinal cord) to the end of the dural sac with which it fuses
A
Filum terminale
17
Q
Provide the strongest anchorage and fixation of the spinal cord to the vertebral canal, which carries motor and sensory fibers
A
Spinal nerve roots
18
Q
What is the shape of the SC?
A
elongated nearly CYLINDRICAL structure, flattened dorsoventrally
19
Q
How many cm in diameter is the SC?
A
approximately 1 cm in diameter
20
Q
What are the enlargements in the SC? (2)
A
Cervical (C5-T1)
Lumbar (L1-S2)
21
Q
What are the vertebral levels of the cervical enlargement?
A
Cervical (C5-T1)
22
Q
The SC terminates as?
A
conus medullaris
23
Q
What are the vertebral levels of the lumbar enlargement?
A
Lumbar (L1-S2)
24
Q
Average length for the spinal cord in males?
A
45 cm
25
Average length for the spinal cord in females?
42 cm
26
How many pairs of nerves emerge from the SC?
31 pairs of nerves
27
Pairs of spinal nerves from each part?
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
28
T OR F: The 7th cervical nerve and the coccygeal nerve usually have no dorsal (sensory) roots and no corresponding dermatomes
FALSE
The C1 NERVE and the coccygeal nerve usually have no dorsal (sensory) roots and no corresponding dermatomes
29
Where does the C1 nerve pass?
between SKULL & ATLAS
30
Where does the C2 nerve pass?
between ATLAS & AXIS
31
With the exception of C1, spinal nerves exit the vertebral canal via ____?
intervertebral or sacral foramina
32
Convey input from skin, muscle, bone, and joints to the CNS
General somatic afferent (GSA) fibers
33
Convey sensory from visceral organs to the CNS
General visceral afferent (GVA) fibers
34
Convey motor output from ventral horn motor neurons to skeletal muscle
General somatic efferent (GSE) fibers
35
Convey motor output from intermediolateral cell column neurons, via paravertebral or prevertebral ganglia to glands, smooth muscle, and visceral organs (sympathetic division of ANS)
General visceral efferent (GVE) fibers
36
Enters the dorsal lateral sulcus as rootlets
Dorsal root
37
The dorsal root convey _____ input from the body via _____?
SENSORY INPUT via DORSAL ROOT GANGLION
38
T OR F: Dorsal root ganglion distally, become rootlets
TRUE
39
The dorsal root joins ventral root ____ to the dorsal root ganglion and within the ______ to form the spinal nerve (peripheral nerve)
distal; intervertebral foramen
40
Dorsal root ganglion contains ______ of neural crest origin
pseudounipolar neurons
41
Dorsal root ganglion rransmits sensory input from periphery via (2)
GSA & GVA
42
emerges as ventral rootlets from ventral lateral sulcus, conveying motor output from visceral and somatic motor neurons
ventral root
43
Cauda equina consists of _____ (dorsal and ventral) nerve roots that descend from the spinal cord through the subarachnoid space to exit through their respective intervertebral or sacral
foramina
LUMBOSACRAL (L2 to Co)
44
What spinal nerve ramus innervates the skin and muscles of the back?
Dorsal primary ramus
45
What spinal nerve ramus innervates the ventral lateral muscles and skin of the trunk, extremities, and visceral organs?
Ventral primary ramus
46
What spinal nerve ramus innervates meninges and vertebral column?
Meningeal ramus
47
White communicating rami contain ____ fibers & myelinated GVA fibers (____ nerves)
myelinated preganglionic sympathetic & myelinated GVA fibers (splanchnic nerves)
48
White communicating rami are found only in ____ segments of the spinal cord?
thoracolumbar (T1-L3)
49
Gray communicating rami contain _____ fibers; associated with all spinal nerves
unmyelinated postganglionic sympathetic
50
One spinal nerve innervates the derivatives from one somite, which includes: (3)
Dermatome
Myotome
Sclerotome
51
consists of a cutaneous area innervated by the fibers of 1 spinal nerve
Dermatome
52
consists of muscles innervated by the fibers of 1 spinal nerve
Myotome
53
consists of bones and ligaments innervated by the fibers of 1 spinal nerve
Sclerotome
54
Underlying the pia mater and include: (5)
- Ventral median fissure
- Ventral lateral sulcus
- Dorsal median sulcus
- Dorsal intermediate sulcus
- Dorsal lateral sulcus
55
a deep anterior midline groove in which the anterior spinal artery is found superficially
Anterior median fissure
56
a shallow groove from which the anterior rootlets emerge.
Anterior lateral sulcus
57
a shallow groove into which the posterior rootlets enter.
Posterior lateral sulcus
58
a shallow groove that is continuous with the posterior intermediate septum, which separates the fasciculus gracilis from the fasciculus cuneatus
Posterior Intermediate sulcus
59
a shallow posterior midline groove that is continuous with the posterior median septum
Posterior median sulcus
60
T OR F: The spinal cord is composed of an inner core of gray matter, which is surrounded by an outer covering of white matter.
TRUE
61
A butterfly or H-shaped in configuration that varies according to spinal cord level
Gray Matter
62
Central canal is located within a thin ___ commissure?
thin gray commissure
63
T OR F: The dorsal horn of gray matter receives and processes sensory input but are only found from T1-L3
FALSE
The dorsal horn of gray matter is FOUND AT ALL LEVELS
64
Gray matter is divided into cytoarchitectural areas called?
Rexed Laminae
65
Nuclei found in the dorsal horn of gray matter (4)
Dorsomarginal nucleus (Rexed lamina I)
Substantia gelatinosa (Rexed lamina II)
Nucleus proprius (Rexed laminae III and IV)
Nucleus dorsalis of Clarke (Rexed lamina VII)
66
What type of input does the lateral horn of gray matter receive?
Receives VISCEROSENSORY input
67
T OR F: The lateral horn of gray matter is found between the dorsal & ventral horns and from T1-L4
FALSE
lateral horn of gray matter is from T1-L3
68
The lateral horn of gray matter contains the _____, a visceromotor nucleus from T1-L3
intermediolateral nucleus
69
What sympathetic neurons does the lateral horn of gray matter contain?
Contains the PREGANGLIONIC sympathetic neurons (GVE)
70
T OR F: The ventral horn of gray matter is predominantly sensory nuclei
FALSE
it is predominantly MOTOR
71
T OR F: The ventral horn of gray matter is found at all levels.
TRUE
72
What are the nuclei included in the ventral horn of gray matter? (5)
○ Spinal border cells
○ Spinal accessory nucleus
○ Sacral parasympathetic nuclei
○ Somatic motor nuclei
○ Phrenic nucleus
73
Consists of bundles of myelinated fibers that surround the central gray matter
White matter
74
White matter consists of ascending & descending fiber pathways called ___?
tracts
75
The white matter is divided bilaterally by sulci into three major divisions. What are the three divisions?
Dorsal column/funiculus
Lateral column
Anterior column
76
Lateral column contains? (4)
dorsal spinocerebellar,
anterior spinocerebellar,
lateral spinothalamic tract,
lateral corticospinal tract
Others:
rubrospinal tract
spino-olivary tract
77
Dorsal column contains? (2)
Fasciculus Gracilis & Cuneatus
78
Anterior column contains? (3)
anterior spinothalamic tract
ventral corticospinal tract
vestibulospinal tract
others:
tectospinal tract
medial reticulospinal tract
lateral reticulospinal tract
79
Dorsal intermediate sulci (demarcates fasciculus gracilis & fasciculus cuneatus) and septa are present
Cervical Cord
80
In the cervical cord, the ventral horns are massive from C_ to C_?
C3 to C8
81
Thin area of Dorsal, Ventral, and Lateral Horn
Thoracic Cord
82
Contains an enlargement which innervates the lower extremities; Looks like a butterfly
Lumbar Cord
83
Contains massive anterior & posterior horns; substantia gelatinosa greatly enlarged
Lumbar & Sacral cord
84
The sacral cord si greatly reduced in diameter at what levels?
S3 TO S5
85
contains posterior horns that are more voluminous than the anterior horns
Coccygeal segment
86
A monosynaptic and ipsilateral muscle stretch reflex; also called as muscle stretch reflex and has an afferent and efferent limb
Myotatic reflex
87
absence of deep tendon reflexes
areflexia
88
Includes muscle spindle (receptor) & a dorsal root ganglion neuron and its Ia fibers
Afferent limb
89
Includes a ventral horn motor neuron that innervates striated muscle (effector)
Efferent limb
90
Most commonly tested muscle stretch reflex (4)
1. Ankle jerk: S1
2. Knee jerk: L2-L4
3. Biceps jerk: C5-C6
4. Triceps jerk: C7-C8
91
Ankle jerk stretch reflex
S1
92
Knee jerk stretch reflex
L2-L4
93
Biceps jerk stretch reflex
C5-C6
94
Triceps jerk stretch reflex
C7-C8
