1. Vertebral Column
Nicole M. Reeves, Ph.D.
Department of Anatomy
NicoleReeves@RossU.edu
Recommended Reading
COA : 7th Edition
Pages: 4-11, 47-60, 440-482, 496-507
*Practice questions can be found on Canvas*
2. Learning Objectives
• Describe the features of a typical vertebra and differentiate between cervical, thoracic,
lumbar, sacral and coccygeal vertebrae
• Describe the pattern of rib articulation with thoracic vertebrae
• Compare movements at the atlanto-occipital & atlanto-axial joints
• Describe the composition & placement of intervertebral discs
• Define normal vertebral curvatures
• Explain the ligaments that stabilize the vertebral column, their attachments, and what
movements they prevent
• Describe blood drainage of the vertebral column
• Explain normal changes in spinal cord length relative to the vertebral column through
development
• Distinguish between the 3 meninges, and describe the real and potential spaces
between the vertebral canal, meninges and spinal cord, and list their contents
2
3. Learning Objectives
• Describe the organization and distribution of the spinal cord & spinal nerves,
particularly in relation to vertebral level
• Describe the termination of the spinal cord and associated structures in the vertebral
and sacral canal
• Relate the anatomical details to these clinical conditions: Vertebral fractures, abnormal
spinal column curvatures, whiplash, epidural anesthetic injection, lumbar puncture,
herniated IV disc (cervical, thoracic and lumbar regions)
• Link the anatomical and clinical information provided from the lecture to the applicable
gross anatomy laboratory
• Use the information provided from the lecture, along with the learning objectives from
the applicable laboratory, as your knowledge base required for practical examinations
3
4. Osteology of the back overview
CLAVICLE
SCAPULA
RIBS
VERTEBRAE
FUNCTIONS
• Protect spinal cord & nerves
• Supports the trunk as a rigid
yet flexible axis for the body;
important for posture &
locomotion
4
5. Vertebral column (n = 33)
CERVICAL
VERTEBRAE
n = 7
THORACIC
VERTEBRAE
n = 12
LUMBAR
VERTEBRAE
n = 5
SACRUM n = 5 fused segments
COCCYGEAL
VERTEBRAE
n = 4 (fused after age 30)
segments
Intervertebral (IV)
discs
5
12. General vertebral anatomy
SUPERIOR VERTEBRAL NOTCH
INTERVERTEBRAL (IV) FORAMEN
(spinal n.)
INFERIOR VERTEBRAL NOTCH
VERTEBRAL BODY
INFERIOR ARTICULAR FACET
(feature on INFERIOR ARTICULAR PROCESS)
SUPERIOR ARTICULAR PROCESS
PEDICLE
TRANSVERSE PROCESS
12
13. Zygapophysial (facet) joint: synovial, plane joint
13
• Articulation of inferior articular
facet of one vertebra with the
superior articular facet of the next
vertebra in sequence
• Note the proximity to intervertebral
foramen (& spinal nerves)
15. Typical cervical vertebrae – C3 – C7
• Small overall size; small bodies
• Large vertebral foramina to accommodate
cervical enlargement of the spinal cord
(think: innervation of the upper limbs)
• Transverse foramen for vertebral a.
• Uncinate process
15
16. Clinical: Proximity of spinal nerve & vertebral artery to the uncinate
process on cervical vertebrae
• Bony outgrowths (osteophytes) on the uncinate process may compress both the nerve & the
vertebral artery & can lead to chronic pain in the neck
• common in elderly patients, results in “mini-stroke”
• Remember: spinal nerves pass through the IV foramina, & vertebral arteries pass through the
transverse foramina
16
17. Cervical vertebrae – C1 (atlas)
FACET FOR DENS of C2
TRANSVERSE
FORAMEN
SUPERIOR
ARTICULAR
FACET
LATERAL MASSES
GROOVE FOR
VERTEBRAL A.
POSTERIOR TUBERCLE
*atlas has no body
ANTERIOR
ARCH
POSTERIOR
ARCH
17
18. Cervical vertebrae – C2 (axis)
DENS
(odontoid process)
TRANSVERSE
FORAMEN
SUPERIOR
ARTICULAR
FACET
INFERIOR
ARTICULAR
FACET
POSTERIOR ARTICULAR
FACET for transverse
ligament of atlas
BODY
BIFID SPINOUS PROCESS
ANTERIOR
ARTICULAR
FACET
(articulates with
C1)
18
19. Atlanto-axial joint
SUPERIOR
ARTICULAR
FACET of atlas
(articulates with
occipital condyle of
cranium)
DENS
of axis
TRANSVERSE
PROCESS
SPINOUS
PROCESS
ATLANTO-AXIAL JOINT
GROOVE
FOR
VERTEBRAL A.
19
POSTERIOR ARTICULAR
FACET for transverse
ligament of atlas
20. Atlanto-occipital & Atlanto-axial joints
ATLANTO-OCCIPITAL JOINT
• head flexion & extension – nod head
yes
ATLANTO-AXIAL JOINT
• rotation – shake head no
20
21. Clinical: Fracture & dislocation of atlas
Burst (Jefferson) fracture (C1)
• compressive loading along the cervical spine results in the occipital condyles being driven into
the lateral masses (LM) of C1
• often a 4 part fracture with double fractures through anterior & posterior arches
• occurs when diving head first into shallow water or after falling from a tall building
21
22. Clinical: Fracture & dislocation of axis (C2)
Hangman’s fracture (C2)
• pedicles fractured posterior to superior articular
facets due to abrupt hyperextension; fracture at
pars interarticularis
• common result of falls & motor vehicle accidents
(hitting chin on steering wheel)
• this injury would occur during judicial hanging,
hence the colloquial name
22
24. Thoracic vertebrae (n = 12)
TRANSVERSE
COSTAL
FACET OF
VERTEBRA
COSTAL
TUBERCLE OF RIB
HEAD OF RIB
SUPERIOR
COSTAL
FACET OF
VERTEBRA
• provide attachment for ribs (costal facets) → stability
of the trunk → less injury in this region
• larger than cervical bodies
• Smaller vertebral foramen (compared to cervical &
lumbar vertebrae)
24
26. Lumbar vertebrae (n = 5)
L1
L2
L3
L4
L5
• LARGE vertebral bodies, which bear the most weight
• orientation of articular facets permits flexion & extension
and lateral flexion, while rotation is prohibited
• vertebral foramen large to accommodate lumbar
enlargement of spinal cord
BODY
26
28. Coccyx (4 fused segments)
Co1
Co2
Co3
Co4
• Coccygeal vertebrae are highly variable and can range from 3-5
• “tail bone”
28
29. Normal vertebral curvatures
CERVICAL LORDOSIS
2 curvature
THORACIC KYPHOSIS
1 curvature
LUMBAR LORDOSIS
2 curvature
SACRAL KYPHOSIS
1 curvature
• Primary (1º) curvatures develop during the fetal
period; newborn spine is kyphotic
• Secondary (2º) curvatures result from extension
from the flexed fetal position; cervical lordosis
develops when infants begin to hold their heads
up; lumbar lordosis develops when toddlers begin
standing & walking; set at puberty
29
30. Clinical: Abnormal curvatures of the vertebral column
Excessive thoracic kyphosis (A)
• term shortened clinically to kyphosis
• colloquially known as hump or hunch back
Excessive lumbar lordosis (B)
• term shortened clinically to lordosis
• colloquially known as sway or hollow back
Scoliosis (C)
• abnormal lateral curvature of the spine
A B C
30
31. INTERVERTEBRAL
DISC (cross-section)
Intervertebral (IV) discs
• IV discs comprise 20% of vertebral column
length
• No IV discs between atlanto-occipital joint,
atlanto-axial joint, sacral segments,
coccygeal segments
• composed of anulus fibrosus (concentric
rings of fibrocartilage that connect
adjacent vertebral bodies) & nucleus
pulposus (semi-gelatinous mass that acts
as shock absorber)
Functions:
• strong attachment between vertebrae;
forms cartilaginous joint
• weight bearing, shock absorption
31
32. Clinical: Herniation/Protrusion of intervertebral discs
• Herniation occurs when the nucleus pulposus
protrudes (herniates) through the annulus fibrosis &
compresses the spinal nerves exiting the IV
foramen [or the vertebral artery exiting the
transverse foramen]
• Most common in cervical & lumbar; 95% of lumbar
disc protrusions occur at L4/L5 or L5/S1
• Many discs herniate – most will resolve on their own
or with PT
• Typically occurs posterolaterally, where anulus
fibrosis is relatively thin & does not receive support
from posterior longitudinal ligament
• stress resistance of the anulus fibrosus declines
with age
32
33. INTERVERTEBRAL
DISC (cross-section)
ANTERIOR
LONGITUDINAL
LIGAMENT
• strong, broad fibrous band
• runs along anterior vertebral
bodies
• prevents hyperextension
POSTERIOR
LONGITUDINAL
LIGAMENT
• narrower, somewhat weaker (than
anterior longitudinal lig.)
• runs within the vertebral canal along
posterior aspect of vertebral bodies & IV
discs
• prevents hyperflexion
LIGAMENTUM
FLAVUM
• elastic, yellow bands of tissue
connecting laminae of adjacent
vertebrae
• limits flexion
INTERTRANSVERSE
LIGAMENTS
Ligaments of the vertebrae
*remember: ligaments connect bone to bone
33
35. Nuchal ligament
• Thick, fibroelastic, median band running
from the external occipital protuberance &
posterior border of the foramen magnum to
C7 spinous process
• Attaches to the spinous processes of
cervical vertebrae
• Allows for attachment of back muscles
where the spinous processes of cervical
vertebrae are shorter
Foramen magnum
Inferior &
Superior
Nuchal lines
35
External occipital protuberance
36. Clinical: Crush or compression fractures
Crush/compression fractures
• Sudden forceful flexion (as in motor vehicle
accidents or severe blows) results in the fracture
of the body of one or more vertebrae
• Can also be accompanied by dislocation &
fracture of the articular facets between two
vertebrae, with rupture of the interspinous
ligaments
36
Chance fracture
• Flexion injury of the spine
• Anterior compression fracture + fractures across transverse
processes
• Back seat passenger restrained by lap seatbelt involved in MVA or
fall from great height
37. Clinical: Whiplash injury
Severe hyperextension of the neck (“whiplash” injury)
• anterior longitudinal ligament is severely stretched & may be torn
• can be accompanied by hyperflexion injury of vertebral column, as head “rebounds” after
the hyperextension
• Hangman’s fracture is one severe example
• Common as a result of MVA
37
38. Organization of the spinal cord and spinal nerves 31 pairs of
spinal nerves
8 Cervical!!
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
1
2
3
4
5
1
12 Thoracic
5 Lumbar
5 Sacral
1 Coccygeal!!
Cervical
enlargement
Lumbar
enlargement
• The spinal cord, with the brain,
forms the Central Nervous System
(CNS)
• The 31 pairs of spinal nerves
arising from the spinal cord form
part of the Peripheral Nervous
System (PNS)
• The spinal cord has two
enlargements, cervical & lumbar,
where there are more nerves for
innervation of the limbs
38
40. Meningeal coverings of the spinal cord
3 Meninges
1. Dura mater (“tough mother”) = outermost layer, thick,
fibrous tissue
2. Arachnoid mater = filmy layer deep to dura mater
3. Pia mater = layer covering the spinal cord
Denticulate ligament: anchors spinal cord to dura mater;
found at midpoint between two spinal nerves
40
41. Meningeal coverings of the spinal cord
3 Associated Spaces
1. Epidural = space between vertebral canal & dura mater; contains fat
2. Subdural (potential space, only seen pathologically) = space between dura mater & arachnoid
mater
3. Subarachnoid = space between arachnoid mater & pia mater; contains cerebrospinal fluid (CSF)
1.
2.
3.
41
42. Termination of the spinal cord
CENTRA OF VERTEBRAE
SPINOUS PROCESSES OF
VERTEBRAE
L1
L2
L3
L4
L5
SACRUM
SPINAL CORD
(surrounded by
meninges)
CAUDA EQUINA – “horse’s tail”
spinal nerve roots travel from
conus medullaris down to their
IV foramen exit
CONUS MEDULLARIS
as spinal nerves “leave,” the
spinal cord narrows into a cone
shape
• Adult: ~L1/L2
• Neonate: ~L3/L4
42
43. Termination of the spinal cord
CONUS MEDULLARIS
CAUDA EQUINA
DURA MATER
ARACHNOID MATER
FILUM TERMINALE
• continues from conus medullaris (~L2) to
coccyx; tethers spinal cord to coccyx
SACRAL HIATUS
DURAL SAC
• Dura mater surrounds cauda equina,
ending at S2, forming a “sac”
LUMBAR CISTERN
• enlargement of subarachnoid space
between conus medullaris (~L2) & end of
dural sac (~S2)
• site for lumbar puncture & spinal anesthesia
43
44. Spinal nerves & vertebral levels
• Cervical nerves course SUPERIOR to
their corresponding vertebra, while all
others course INFERIOR to their
corresponding vertebra
• C1 spinal nerve courses SUPERIOR to
the C1 vertebra
• NOTE: C8 spinal nerve courses inferior to
the C7 vertebra, superior to the T1
vertebra
• T1 spinal nerve courses INFERIOR to the
T1 vertebra 44
45. L5 vertebra
L4 vertebra
Intervertebral disc protrusion & spinal nerve compression
• In the cervical & thoracic regions, when an IV disc
protrudes, the spinal nerve coursing through the
associated IV foramen will be compressed
• Example: IV disc herniation between C4 & C5 will compress
spinal nerve C5 (C5 spinal nerve coursing superior to C5
vertebra)
• Example: IV disc herniation between T4 & T5 will compress
spinal nerve T4 (T4 spinal nerve coursing inferior to T4
vertebra)
• HOWEVER – this is NOT the case for the lumbar
region!
• L4 spinal nerve EXITS between L4/L5, but sneaks by
against the body of L4 vertebra; Instead, L5 spinal
nerve is COMPRESSED by a protrusion of the IV disc
at L4/L5 level
*Note: In the cervical and lumbar regions, the spinal
nerve with the number of the inferior vertebra, but by two
DIFFERENT mechanisms.
**In the lumbar region, there is a difference in where a
spinal nerve EXITS & where it is COMPRESSED**
45
L4 spinal n.
L5 spinal n.
L4 spinal n.
L5 spinal n.
46. Clinical: Lumbar Puncture (spinal tap)
& anesthesia during childbirth
Lumbar Puncture – Adults only (1, 2)
• enter into lumbar cistern through L4 level
• typically to collect CSF for evaluating infections of
the CNS (e.g. Meningitis)
Spinal anesthesia (1, 2)
• anesthetic inserted in same place as lumbar
puncture (usually L4 level)
• complete anesthesia below the waist
• risks leakage of CSF
Epidural anesthesia (1, 2, 3)
• anesthetic agent inserted in extradural space, either
in same position as lumbar puncture (L4 level), or in
sacral hiatus
46
47. Venous drainage of the vertebral column
Spinal veins form plexuses along the vertebral column inside & outside the vertebral canal.
47
INTERNAL vertebral venous plexuses (epidural
venous plexuses)
• has anterior & posterior components
• *valveless veins → potential path for cancer
metastasis [from breasts, lungs, and prostate
gland to the brain]
• Veins of internal vertebral plexus connect with veins in the
body cavities & are continuous with the cranial dural
venous sinuses through the foramen magnum
EXTERNAL vertebral venous plexuses
• has anterior & posterior components
Basivertebral veins form within the vertebral
bodies
48. Additional slides:
(These slides are included to help clarify presented concepts or to
provide additional clinical correlates. You are responsible for
understanding these concepts.)
48
51. Schematics of the vertebral ligaments
Body only Entire vertebrae
ANTERIOR
LONGITUDINAL
LIGAMENT
POSTERIOR
LONGITUDINAL
LIGAMENT
INTERVERTEBRAL
DISC
LIGAMENTUM FLAVUM
SUPRASPINOUS LIGAMENT 51
INTERSPINOUS
LIGAMENT
52. Clinical: Osteoporosis
• In osteoporosis, more bone material
gets reabsorbed than built up,
resulting in a loss of bone mass
• Spine is most affected by degenerative
diseases of the skeleton, such as
osteoporosis
• Symptoms include compression
fractures and resulting back pain
Radiograph of normal lumbar
spine (L lateral view)
Radiograph of osteoporotic lumbar spine with
a compression fracture at L1 (arrow). Note
that vertebral bodies are decreased in density,
& internal trabecular structure is coarse.
52
53. Clinical: Coccygeal injury
Coccydynia
• localized pain & tenderness in tailbone region
• usually caused by trauma to the coccyx
• direct injury during contact sports
• coccyx can fracture during childbirth
• repetitive straining or friction
• fall onto the coccyx in the seated position
53
54. Clinical: Disk herniation in the lumbar spine
• Posterior herniation (A,B): In the MRI, a conspicuously herniated disk at the level of L3-L4
protrudes posteriorly (transligamentous herniation). The dural sac is deeply indented at that level;
*CSF - cerebrospinal fluid
54
55. Clinical: Disk herniation in the lumbar spine
• Posterolateral herniation (D): A posterolateral herniation may spare the nerve at that level but
impact nerves at inferior levels.
55
56. Clinical: Spina bifida
SPINA BIFIDA OCCULTA
• Birth defect where neural arches of L5 and/or S1 fail to develop
normally & fuse posterior to the vertebral canal
• Defect present in up to 24% of the population; most have no
back problems
• Defect is concealed by the overlying skin, but its location is
often indicated by a tuft of hair
SPINA BIFIDA CYSTICA
• More severe form of spina bifida, where one or more vertebral
arches fail to develop completely
• Severe forms of spina bifida result from neural tube defects,
such as defective closure of the neural tube during 4th week of
embryonic development
• Associated with herniation of the meninges (meningocele, a
spina bifida associated with a meningeal cyst) and/or the spinal
cord (meningomyelocele)
• Neurological symtoms usually present in severe cases of
meningomyelocele (e.g. paralysis of the limbs & disturbances in
bladder & bowel control)
56
57. Clinical: Lumbar stenosis
• Stenosis (narrowing) of lumbar vertebral
foramen in one or more lumbar vertebrae
• May be hereditary anomaly, making a
person more vulterable to age-related
degenerative changes such as IV disc
bulging
• Surgical treatment of lumbar stenosis
may consist of decompressive
laminectomy
57
58. Clinical: Ankylosing spondylitis
• A form of spinal arthritis; it’s an inflammatory disease
• Affects males more often than females
• Causes ankylosis (fusion or fixation) of multiple vertebral and/or vertebral + sacroiliac joints
• Fusion makes the spine less flexible and can result in a “hunched-forward” posture
58
