KH 2220
Laura Abbott, MS, LMT
Day 5
Boney Landmarks and Structure
of the Vertebral Column
Spinal Column
• The vertebral column is often called the “spinal
column” or the “spine”.
• In adults, it consists of 26 bones.
• The top 24 bones are called vertebrae and the
bottom two are called the sacrum and coccyx.
• Running through the center of the vertebral
column is the spinal canal, which contains the
spinal cord.
• Nerves emerge from the spinal cord and exit
between the vertebrae.
5 Sections of Vertebral Column
•
•
•
•
•
cervical (neck) section: top 7 vertebrae
(C1-C7)
thoracic (upper back) section: 12
vertebrae (T1-T12)
lumbar (lower back) section: 5 vertebrae
(L1-L5)
sacrum: 5 fused bones
coccyx: 3-5 fused bone
Normal Curves of the Spine
• Lordotic
• Kyphotic
Abnormal Curves of the Spine
• Lordosis
Abnormal Curves of the Spine
• Kyphosis
Abnormal Curves of the Spine
• Scoliosis
The Typical Vertebra
•
•
•
The vertebral body is the large rounded
portion that forms the anterior part of the
vertebra.
The vertebral foramen is the large hole
posterior to the body. When all the vertebrae
are in their proper position, their vertebral
foramina form a continuous tube- the spinal
canal.
The pedicles and the laminae form the walls
of the vertebral foramen.
The Typical Vertebra
•
•
•
The transverse processes are lateral
projections on the vertebra.
The spinous process is a projection on
the posterior part of the vertebra.
The superior articular processes are
two projections on the superior surface of
the vertebra. Each one has a flattened
surface called a facet.
The Typical Vertebra
•
The inferior articular processes: two projections on
the inferior surface of the vertebra. Each of these also
has a flattened surface called a facet. The picture
below shows how the superior articular processes of
one vertebra meet the inferior articular processed of
the overlying vertebra to form a joint.
•
Intervertebral foramen: a hole, which is formed by
the meeting of two vertebrae. Spinal nerves exit the
spine through the intervertebral foramen. It is at this
point that spinal nerves can be impinged upon,
resulting in severe pain or
Cervical Vertebra
• Cervical vertebras have
small bodies and large
vertebral foramina. The
transverse processes of
each vertebra have a
transverse foramen. The
transverse foramina
provide passage for the
vertebral artery, which
supplies the brain.
C1-The Atlas
• The two unique structural
features of the atlas are:
• it has no body
• it has no spinous process
Other points of interest:
• The vertebral foramen is huge
because it has to provide
passage for the spinal cord
which, at this level is also
huge.
• The transverse processes are
very prominent and may be
palpated just inferior to the
mastoid process
• The atlas has 2 massive
superior articular processes
whose bowl-shaped facets
accommodate the condyles of
the occipital bone. This joint
enables the occipital bone to
rock back and forth on the
atlas, thus allowing us to nod
our heads “yes”
C2- The Axis
• The second cervical
vertebra, or axis, from
above is also unique. Its
spinous process is quite
massive.
• The key feature of C2 is
the odontoid process an
upward projection, which
fits, into C1.
• The joint between C2 and
C1 allows us to shake our
heads “No”.
Thoracic Vertebrae
• have long slender spinous
processes, which are oriented
sharply downward.
• have flattened surfaces on the
transverse processes and
bodies for attachment of the
ribs. These surfaces are
called facets on the transverse
processes and demifacets on
the bodies.
• Due to the attachment of the
ribs to the thoracic vertebrae,
the thoracic section is not as
freely moveable as the cervical
section.
Lumbar Vertebrae
• Whereas the cervical
vertebrae are highly
mobile, the lumbar
vertebrae are built for
strength.
• They have large
bodies and massive
spinous processes
that are oriented
straight back
The Sacrum
• In adults, the sacrum consists of 5 fused
bones, which are designated as S1-S5.
• Between the fused segments are sacral
foramina on the anterior and posterior
surfaces of the sacrum.
• At birth, the 5 sacral segments are not
fused. They remain as 5 separate bones
until about the age of 20.
The Coccyx
• The coccyx consists
of 3-5 fused bones.
• It is considered to be
the vestige of a tail.
In fact, babies are
often born with a
small tail, which
projects down from
the tip of the coccyx.
Discs
• The intervertebral disc is situated
between adjacent vertebral bodies.
• It consists of an outer ring of fibrocartilage
called the annulus fibrosis, and a soft
gelatinous interior called the nucleus
pulposus.
The Herniated Disc
• The term “slipped disc” is a misnomer
• It is possible to have a bulging disc, wherein the
annulus fibrosis is overstretched and the
nucleus pulposus balloons out.
• Even more serious is a ruptured disc, wherein
the annulus fibrosis is torn, and the nucleus
pulposus escapes.
• A bulging or ruptured disc may be called a
HERNIATED disc. A herniated disc can press
upon a spinal nerve root or even the spinal cord,
causing severe pain
The Disc has 2 functions
–
–
It firmly joins the
bodies of adjacent
vertebrae
The soft nucleus
pulposus makes the
disc an effective
cushion that protects
the vertebral bodies
from too much
compression.
Ligaments of the Spine
•
•
•
The anterior
longitudinal ligament
is a broad flat ligament
that runs along the
anterior surface of the
vertebral bodies.
It links the bodies
together and fuses with
the discs.
Its function is to prevent
excessive extension of
the vertebral column.
Ligaments of the Spine
• The posterior
longitudinal ligament
runs along the back of the
vertebral bodies.
• It is thinner and more
delicate than the anterior
longitudinal ligament.
• Its function is to prevent
excessive flexion.
Ligaments of the Spine
• The nuchal ligament
runs from the EOP
(external occipital
protuberance) to the
spinous process of
C7.
Ligaments of the Spine
• The supraspinous
ligament is a thin
stringy ligament that
joins the tips of the
spinous processes.
Ligaments of the Spine
• The interspinous
ligaments are
situated between the
spinous processes of
adjacent vertebrae.
• Numerous muscles
help to hold the
vertebrae together.
Spondylolysis
• “Stress fractures” of
the spine
• Low back pain
• Not always a
definitive cause.
Some people develop
it with no history of
back injury, others
may have it and have
no pain.
Spondylolisthesis
• Slippage of vertebrae
–usually L5-S1
• Pain that worsens
with spinal flexion and
relieved with spinal
extension
• Causes: traumatic
injury, degeneration,
and rarely,
pathological (tumor
leading to lesions)
Stenosis
• Abnormal narrowing
of the spinal canal
• Most common in
cervical and lumbar
regions
• Caused by
degeneration, less
commonly by tumors
• Symptoms – pain,
numbness, weakness
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