GA3: Vertebral Column and Spinal Cord Flashcards
(131 cards)
1
Q
Describe some main functions of the Spinal Column
A
- Maintenance of the erect posture and aids in locomotion.
- Support of the trunk, limbs, & head
- Protection of the spinal cord & spinal nerve roots
2
Q
What spinal curvatures are present in a newborn?
A
Two Primary (kyphotic) curvatures: Thoracic and sacrococcygeal
3
Q
describe the Kyphotic curvatures?
A
primary Thoracic and sacrococcygeal: Concave anteriorly; Curvature due to variation in the A-P heights of the vertebrae
4
Q
Describe the Lordotic curvatures
A
Secondary cervical and lumbar. Cervical (from holding up head) Lumbar (from developing erect posture Both are convex posteriorly Curvature d/t variation in A-P thickness of IV discs`
5
Q
Describe Excessive thoracic Kyphosis
A
increase in thoracic curvature (humpback) from weakening of thoracic bodies.
Common in osteoporosis, spinal tuberculosis, osteomalacia/rickets
6
Q
Excessive Lumbar Lordosis
A
Increase in lumbar curvature (swayback), common in late pregnancy
7
Q
Scoliosis
A
Lateral cuvaures of the spine; may be idiopathic or can develop in association with postural imbalance d/t genetic defects and injury. Most commonly seen in adolescent girls; can be managed with PT/back brace/ insertion f steel rods
8
Q
What is the total number of vertebrae in humans?
A
33
9
Q
of cervical vertebrae
A
7; C1-C7
10
Q
of thoracic vertebrae?
A
12; T1-T12
11
Q
of Lumbar Vertebrae?
A
5; L1-L5
12
Q
of sacral vertebrae?
A
5; S1-S5 Fused to form Sacrum
13
Q
of coccygeal vertebrae?
A
3-4; fused to form coccyx
14
Q
What is the Vertebral Arch Composed of?
A
2 Pedicles
2 Laminae
Vertebral Foramen which for the vertebral canal when stacked
15
Q
What are the muscle attachments of the vertebrae?
A
Transverse Processes & Spinous Process
16
Q
What are the Zygapophyses?
A
The Superior and Inferior Articular Processes; They have facets for articulation with vertebrae above and below.
+ Their orientation determines the types of movements allowed
17
Q
What are the notches formed between the projection of the vertebral body and articular processes superior and inferior to the pedicles?
A
Superior and Inferior Vertebral Notches
18
Q
Superior & inferior vertebral notches of adjacent vertebrae form _________ ________ which permit the passage of spinal nerve roots & contain spinal dorsal root ganglia & vessels
A
Intervertebral Foramina
19
Q
Name the Boundaries of the intervertebral Foramina
A
Anterior boundary: intervertebral disc and vertebral bodies of adj vertebrae.
Superior/ Inferior: Pedicles of adjacent vertebrae
Posterior: Ligamentum flavum & capsule of Zygapophhyseal joint
20
Q
Characteristics of cervical vertebrae
A
- Transverse foramina ( intransverse processes; transmit vertebral arteries)
- Ant/Post Tubercles on transverse foramen
- Bifid spinous processes (absent on C1, long and slender on C7)
- Small bodies (C1 has no body), delicate arches
21
Q
Describe the shape and Characteristics of the Atlas
A
C1 is ring-shaped with NO bony or Spinous Process.
Ant/Post arches, Ant tubercule, Post tubercle.
Articular Facet for dens on the anterior arch.
Bilateral grooves in the post arch for the Vertebral Arteries
Sup/Inf articular facets on the lateral mass (not on zygapophyses)
22
Q
Describe the shape and Characteristics of the Axis
A
C2 has a Dens (Odontoid process) with articular facet on its ant aspect.
The inf facets are on Zygapophyses (sup facets are not)
23
Q
Describe the Differentiating Characteristics of the Thoracic Vertebrae
A
- Transverse Costal facet on transverse process (articulates w/ tubercle of same# rib)
- Costal hemifacits (sup & inf): on T2-T9 or T10 bodies. A half-articulation point in sup/inf pairs shared with adj vertebra
- Costal facets: larger articular surfaces on bodies for articulation with the heads of ribs (Sup facet of T1, T10-T12 have only one costal facet per side & articulate with only one rib each)
- Heart-shaped body; circular vertebral foramina
- Spinous processes are long & flat, angled down
- Sup articular facets face posteriorly & inferior facets face anteriorly
24
Q
What Thoracic vertebrae do not have hemifacets?
A
T1, T10, T11, T12; articulate with 1 rib each
(Sup facet of T1 is NOT a hemi facet Rib 1 articulates with T1; Vertebrae T10-T12 have only one costal facet per side & articulate with only one rib each)
25
What characteristics distinguish the Lumbar Vertebrae?
1. Bodies are large and kidney-shaped
2. Spinous Processes are blunt, stocky, & project posteriorly
3. Articular processes are large; superior articular facets medially & inferior facets face laterally
4. Superior articular facets exhibit mammillary processes- multifidus m attachments
5. Transverse processes are long and slender
6. Accessory processes - located btwn & inf to the mamillary & transverse processes - attachment for longissimus m.
26
Where is the sacral Promontory?
The ventral projection of the base (which articulates with the L5 intervertebral disc)
27
What is the Apex of the sacrum?
directed inferiorly and articulates with the coccyx
28
4 pairs of ________ __ _______ ________ ________ permit passage of dorsal & ventral rami of sacral spinal nerves.
Dorsal & Ventral Sacral Foramina (sacral intervertebral foramina)
29
Describe the median Sacral crest
On the post surface of sacrum fused rudimentary spinous processes of S1-S3/S4
30
Sacral hiatus
Where the vertebral canal -- sacral canal ends.
| Can be used for extradural anesthesia
31
Sacral Cornu
inf horns of S5 vertebra on each side of sacral hiatus
32
Describe the Auricular surface
The lateral surface of the sacrum; looks like and auricle (ear); synovial part of sacroiliac joint
33
Describe the Coccygeal vertebrae (coccyx)
- 4 fused rudimentary vertebrae
| - No vertebral canal
34
What are intervertebral joints?
Symphysis-type joint between fibrocartilage intervertebral (IV) discs & articular surfaces of vertebral bodies
35
__________ are designed for weight bearing & strength; allow some mvmt at the intervertebral joints
Consist of Anulus fibrosus
Intervertebral discs (IV discs)
36
What is Anulus fibrosis?
An outer fibrous ring that inserts into the rim of the vertebral bodies; provides a strong bond btwn adj vertebrae
37
Describe the Nucleus pulposus
The gelatinous highly elastic central core of the IV disc; has a high water content that decreases with advancing age; acts as a shock absorber & semi-fluid ball bearing;
It is Avascular
38
What total length do Intervertebral discs contribute to the spinal column?
IV discs make up 1/4 to 1/3 the total length of the spinal column
39
Variance in the shape and thickness of the IV discs produce what change to the spinal column?
The secondary curvatures of the spine
40
Which vertebrae above the sacrum do not have an IV disc between them?
C1-C2
41
Where are Zygapophyseal Joints?
Between the Sup and inf articular facets of adj vertebrae; synovial plane joints
42
What are the different movements of the Zygapophyseal joints in the Cervical, thoracic, and lumbar regions?
a. Cervical joints are primarily in a horizontal plane and allow mvmt in most directions.
b. Thoracic joints line in the coronal plane which allows lateral flexion
c. Lumbar joints are in sagittal plane which allows flexion/extension
43
Joints formed by the articulation between the head of a rib and the hemifacets on bodies same-numbered and sup adj thoracic vertebrae?
Costovertebral joints;
| synovial plane joint
44
What are the joints formed by the articulation btwn the tubercle of a rib and the transverse process of the same-numbered vertebra?
found at T1-T10 levels
Costotransverse joints;
| Synovial plane joint
45
Describe the Anterior Longitudinal ligament
A broad band attached along the anterior surfaces of the vertebral bodies & IV discs from the occipital bone to the sacrum; helps prevent hyperextension of vert column;
May be dmgd or stretched as a result of whiplash
46
Posterior longitudinal ligament
A thin band attached along the post surfaces of the vertebral bodies and IV discs from C2 to the sacrum;
Weakly resists hyperflexion- prevents vert from slipping post into vertebral canal
47
Ligamentum Flavum (pl. ligamenta flava)
Paired ligaments joining the laminae of adj vertebrae on the post wall of the vertebral canal;
Their fibers contribute to post boundaries of the intervertebral foramina;
Helps in recoil from ant flexion & to maintain upright posture
48
Supraspinous ligament
Unites the tips of the spinous processes
49
What are the ligamentum nuchae?
Thickening of the Supraspinous ligaments in the cervical region
50
Interspinous ligaments:
Located btwn the bases of adj spinous processes;
| limit flexion
51
What are the two major subdivisions of the Nervous system?
1. Central Nervous System (CNS)
| 2. Peripheral Nervous System (PNS)
52
What is the Central Nervous system?
Brain and spinal cord
53
What is the peripheral Nervous system?
All parts external to CNS
1. 12 pairs of Cranial nerves that arise from the brain
2. 31 pairs of Spinal Nerves that arise within or are attached to the spinal cord (includes Somatic Motor and Somatic Sensory nerves)
+ some spinal nerves have peripheral parts of ANS
54
Where does the spinal cord begin and end?
It is contiguous w/ the brain stem and runs inferiorly from the Foramen magnum to the L1 or L2 Vertebrae
55
Describe the Function of the Spinal cord
1. involved in motor & sensory innervation of the body inferior to the head
2. provides a two-way conduction pathway for signals btwn the body & the brain
3. A major center for reflexes
56
What tissues make up the Spinal cord?
1. Gray matter - central core
| 2. White matter - external layer
57
Describe the central core of gray matter
includes cell bodies of motor neurons & interneurons;
| In cross-section it is H shaped w/ 2 dorsal horns (columns) & 2 ventral horns
58
Describe the structure of the white matter
made of axons & glial cells; Does NOT contain neuronal cell bodies
59
What areas of the spinal cord are enlarged?
- Regions that innervate the limbs have more motor Neuron bodies
a. Cervical enlargement (related to upper limbs)
b. Lumbar Enlargement (related to lower limb)
60
What is the tapered inferior end below the lumbar enlargement?
The conus medullaris
61
How many segments does the spinal cord have?
| 1 segment = 1 pair of spinal nerves
31
62
How many cervical segments of the spinal cord?
8 (starts above C1, ends below C7)
63
How many thoracic segments of the spinal cord?
12
64
How many lumbar segments of the spinal cord?
5
65
How many sacral segments of the spinal cord?
5
66
How many coccygeal segments of the spinal cord?
1
67
Several _________ emerge from the dorsal & ventral surfaces of the spinal cord & unite to form the dorsal & ventral ______ of the spinal cord.
a. fila (filum; axons)
| b. roots
68
What type of axon fibers does the Dorsal root cary to the spinal cord?
Sensory (afferent) axon fibers toward the spinal cord
69
Where are the cell bodies of the Dorsal root located?
In the dorsal root ganglion
70
What type of axon fibers does the Ventral root cary away from the spinal cord?
- motor axons (efferent axons) course away from the spinal cord.
71
Where are the cell bodies of the Ventral root motor fibers located?
In the gray matter of the spinal cord
72
What are the two types of nerves that the Ventral root (anterior root) contains?
a. Somatic motor nerves
| b. Autonomic (visceral) motor nerves
73
Describe what Somatic motor nerves control
voluntary muscle fibers;
| these axons are found in every Ventral root
74
What do the Autonomic (visceral) motor nerves control?
Involuntary muscke fibers & certain glands;
| Their axons are only in certain ventral roots
75
The Autonomic motor nerves found in what specific ventral roots?
a. Sympathetic fibers are in T1-L2
| b. Parasympathetic fibers are S2-S4
76
The ________________ is formed by the union of the dorsal & ventral nerve roots, which usually occurs just external to an intervertebral foramen or at their points of exit from the vertebral canal
Spinal nerve proper (mixed spinal nerve)
77
What types of axons does the Spinal Nerve proper (mixed spinal nerve) contain?
Both motor & sensory axons
-typically only a few mm long then divides into Dorsal & ventral primary rami
78
What does the Dorsal (post) primary ramus supply?
a. Supplies both motor & sensory innervation to deep back muscles
b. Gives off a posterior cutaneous nerve to skin of back muscles
79
What does the Ventral (ant) Primary Ramus supply?
a. Supplies both Motor & sensory innervation to muscles of the lateral & anterior body wall, & the limbs
b. Supplies cutaneous sensory (lateral cutaneous nerve & Ant cutaneous nerve) to these regions
c. Ventral rami that supply the limbs and neck join one another to form Plexuses (brachial plexus)
80
In the Sacral regions, dorsal rami emerge through ________ _______ ________ & ventral rami emerge through ________ __________ _______
a. Dorsal sacral foramina
| b. Ventral sacral foramina
81
Except for the ____ & ____ cervical nerves, dorsal ramus of every spinal nerve is much smaller in diameter than the ventral ramus
A. 1st & 2nd
---> Dorsal ramus of C2 is the Greater Occipital nerve
82
The Dorsal ramus of C2 is the _____________nerve
Greater occipital
83
Ventral ramus of every spinal nerve is connected to the _____ _____ by 1 or 2 rami communicantes
sympathetic trunk
| (Parts of the ANS)
84
Spinal cord is in the ______ canal, surrounded by ______
a. vertebral
| b. meninges
85
In an embryo, the vertebral column and the spinal cord are the same length, but the vertebral column thereafter grows _______ than the spinal cord
Faster
86
At birth, the spinal cord ends at the ______ vertebral body
L3
87
The adult spinal cord ends at about the level of ________
L1-L2 intervertebral discs
88
Explain where the Spinal cord segments are in relation to the corresponding vertebra in an adult
Spinal cord segments are at the same level as the coresponding vertebra in the upper cervical region, but all other spinal cord segments are superior to the correspondingly numbered vertebra;
a disparity that increases as you go down.Thus , cord segment T5 is at the level of vertebra T3, & the cord segment S5 is at the level of vertebra L1
89
Inf to the conus medullaris, ________________ droop down, heading for lumbar & sacral intervertebral foramina.
long dorsal & ventral roots
| Cauda equina
90
What do the drooping dorsal and ventral roots (beneath L2) constitute?
The cauda equina (horses tail)
91
Points of exit of spinal nerves from the vertebral column
1. exit the vertebral canal via intervertebral foramina or sacral foramina
2. There are 8 cervical nerve pairs & only 7 vertebrae
3. Thoracic, lumbar, & sacral spinal nerves all exit INFERIOR to the correspondingly numbered vertebrae
92
Where does the 1st spinal nerve exit?
btwn the skull & the C1 vertebra, post to the atlatooccipital synovial joints
93
Where do the 2nd spinal nerves exit?
btwn the C1 & C2 vertebrae, post to the lateral atlanto-axial joints
94
The last 2 spinal nere pairs S5 & the coccygeal nerves exit through the _____
Sacral hiatus
95
Nerves C1-C7 exit ________ to correspondingly numbered vertebrae
SUPERIOR
96
Nerve C8 emerges where?
Between vertebra C7 & T1
97
What is a herniated disc?
The protrusion of the nucleus pulposus may compress spinal nerve roots or the spinal nerve proper causing pain (radicular pain) & muscle weakness along the dermatome and myotome.
Most often occurs in the cervical and lumbar regions
98
A herniation in the lumbar region will usually impinge on the nerve that emerges through the ________ subadjacent intervertebra as the nerve descents past the abnormal disc.
a. Superior
| each spinal nerve emerges through the superior part of the intervertebral foramen
99
What is a Dermatome?
Segmental bands of cutaneous sensory innervation; one for each spinal segment
100
The _______ ______ of the _____ nerve is is purely motor and has NO cutaneous sensory branches, so there is No ____ Dermatome
a. Dorsal ramus
b. C1
c. C1
101
Does cutting a single spinal nerve (or dorsal root) produce anesthesia in its dermatome? And why?
No, consecutive dermatomes overlap one another ( there is only a slight reduction in sensitivity; but more noticeable if 2 dermatomes were cut)
102
What are the 3 layers of the meninges
1. Pia mater (most deep) "gentle mother"
2. Arachnoid mater (middle layer) "spidery mother"
3. Dura mater (superficial layer) "tough mother"
103
Describe the Dura mater
The outermost layer;
| made of tough fibrous connective tissue
104
Where does the Dural envelope start and end?
extends from the brain to beyond the end of the spinal cord at S2 vertebral level.
105
What is the Filum terminale externum?
A slender ligament that continues inf from the dura mater & anchors the dura to the coccyx
106
Describe the structure of the arachnoid mater?
it is a delicate transparent membrane lining dura.
| Slender strands called Arachnoid trabeculae (resembles cobweb stands) connect to pia mater
107
Describe the structure of Pia mater
Thin layer adhered directly to the brain, spinal cord & spinal nerve roots
108
What are Denticulate ligaments?
Strong lateral extensions of the pia that anchor the spinal cord laterally to the dura; located btwn the dorsal and ventral roots;
These ligaments pin the arachnoid membrane to the dura btwn the spinal nerves
109
What is a Filum Terminale Internum?
A strong strand of pia that extends inferiorly beyond the conus medullaris to the terminal end of the dural-arachnoid sac
110
Injury to spinal cord above C3
may require a ventilator for breathing
111
Injury to spinal cord above C4
means loss of mvmt & sensation in all limbs, but shoulder & neck mvmts are often available
112
C5 injuries
Often spare shoulder and biceps control, but loss of wrist or hand mvmts
113
Name the spaces associated with the Meninges
1. Epidural space (extradural space)
2. Subdural space
3. Subarachnoid space
114
Where is the epidural space?
1. btwn the dura mater & wall of vertebral canal
2. Within the braincase, dura is fused to the periosteum of the skull, which is considered part of the cranial dura. (there is no fat fuesed epidural space here)
115
What are the soft,fat & and thin-walled veins in the epidural space called?
Internal Vertebral Venous Plexus
116
Describe what an epidural injection is
A local anesthetic that c an be injected into the epidural space to numb pinal nerves located inferior to the injection site (done at sacral region in infants and lumbar regions in adults )
117
Describe the subdural spance
A potential space btwn the dura and arachnoid mater;
| normally only contains a film of watery liquid
118
Describe the subarachnoid space
1. located btwn the arachnoid & pia mater
| 2. Full of cerebrospinal fluid (CSF)
119
What is the lumbar cistern
The large space btwn the tip of the spinal cord & tip of dural-arachnoid sac
120
What does the CSF do?
a. Pressure of the CSF pushes arachnoid membrane against dura
b. buoys up the spinal cord and brain
121
What is in the Lumbar Cistern?
a. the Cauda equina
122
What is the safest place to sample the CSF?
In the Lumbar cistern because the cauda equina is unlikely to be injured by the needle
123
Descripe a lumbar puncture (spinal tap)
A needle is inserted btwn lower lumbar spinous processes or laminae into the lumbar cistern
124
What are intrathecal injections
(theca = sheath)
injections given to the subarachnoid space; typically useful in spinal anesthesia, chemotheraoy, or pain mgmt;
Also to administer drugs to CNS to avoid the blood-brain barrier
125
What are the 6 arteries that the spinal cord arteries arise from?
```
branches of the:
1. Vertebral
2. Ascending Cervical
3. Deep cervical
4. Intercostal
&
5, Lateral sacral arteries
```
126
Name the 3 longitudinal arteries of the spinal cord
1. Anterior spinal artery
| 2. Paired (2) Posterior spinal arteries
127
What does the Anterior Spinal Artery originate from in the spinal cord and where does it branch to?
a. It is formed by union of branches of vertebral arteries
| b. It courses inferiorly in ventromedian fissure on pia mater
128
What do the Paired Posterior Spinal Arteries originate from and where do they branch to? (in spinal cord)
a. they are each a branch of a vertebral artery
| b. they course inferiorly on the pia mater
129
Where do the Segmental Spinal Arteries enter and what branches do they give off? (in spinal cord)
a. enter each vertebral foramen
b. gives off 2 sets of branches:
1. One to the vertebrae, epidural fat, and dura
2. and dorsal & ventral radicular (medullary) branches to spinal nerve roots
130
Describe the venous drainage of the spinal cord
1. Radicular veins drain into internal vertebral venous plexus
2. Venous plexus drains (via intervert foramina) into vertebral, intercostal, lumbar, and lateral sacral veins
3. The valveless nature of these veins permits blood to flow in both directions
131
What contributes to the spread of cancerous or infectious agents from the spinal cord to the vertebrae, brain or skull?
The valveless (valve-less) nature of the spinal cord veins
