Download Vertebral Column - Ms. Zhong`s Classes

Vertebral Column
Vertebral Column (Spine)
• Extends from the skull, which it supports, to
the pelvis, where it transmits the weight of
the body to the lower limbs
• The spine is formed from 26 irregular bones
connected and reinforced by ligaments in such
a way that a flexible curved structure results
Vertebrae
• Before birth, the spine consists
of 33 separated bones called
vertebrae, but 9 of these
eventually fuse in to 2
composite bones
• Of the remaining 24 single
bones:
7 vertebrae of the neck
(cervical vertebrae)
12 thoracic vertebrae
5 lumbar vertebrae
supporting the lower back
Intervertebral disks
• Cushion the vertebrae and absorb shocks
- In a young person, the disks have a high water
content
- As a person ages, the water content of the
disks decreases, and the disks become harder
and less compressible
- Drying of the disks, along with a weakening of
the ligaments of the vertebral column
predisposes older people to herniated
(slipped) disks
Spinal Curvatures
Functions:
1. The disks and the S-shaped structure of the
vertebral column work together to prevent
shock to the head when we walk or run
2. They also make the body trunk flexible
Spinal Curvatures
• Primary curvatures: The
curvatures that are present
when we are born.
e.g. The spinal curvatures in
the thoracic and sacral (lower
spine) regions
• Secondary curvatures: The
curvatures that are present
after we are born.
e.g. The cervical (neck)
curvature
Abnormal Spinal Curvatures
Vertebrae Structure
• Body or Centrum:
Disk like, weightbearing part of the
vertebra facing
anteriorly in the
vertebral column
• Vertebra Foremen:
Canal through which
the spinal cord passes
Vertebrae Structure
• Spinous process:
Single projection
arising from the
posterior aspect of
the vertebrae
• Transverse processes:
Two lateral
projections from the
body
Vertebrae Structure
• Superior and inferior
articular processes:
Paired projections
lateral to the
vertebral foramen,
allowing a vertebra to
form joints with
adjacent vertebrae
Cervical Vertebrae
• The 7 cervical vertebrae
(C1-C7) form the neck
region of the spine.
• The first 2 vertebrae are
different because they
perform functions not
shared by the other
cervical vertebrae
Cervical Vertebrae C1
• The 7 cervical
vertebrae (C1-C7) form
the neck region of the
spine.
• C1 is called the atlas. It
has no body, and large
depressions on the
surface where the skull
sits. It articulates with
the occipital condyles,
and allows you to nod
“yes”
Cervical Vertebrae C2
• C2 is called the axis, and
acts as a pivot point for
rotation of the atlas and
the skull.
• It has a large process
called the odontoid
process, which sticks into
the atlas.
• The joint between C1 and
C2 allows us to rotate the
head from side to side
“no”
Cervical Vertebrae C3-C7
• The C3 through C7
vertebrae are typical
vertebrae with some
features that will identify
them as cervical
vertebrae:
• They are the smallest and
lightest vertebrae
• They have short spinous
processes that are divided
in two
Cervical Vertebrae C3-C7
• They have foramen in
their transverse
processes – this is
what one can use to
identify these
vertebrae as cervical
vertebrae;
• The foramina are
where the vertebral
arteries run through
Superior
and lateral
views of the
cervical
vertebrae
Thoracic Vertebrae
• The 12 thoracic
vertebrae (T1-T12) are
all typical
Thoracic Vertebrae T1-T12
• Their bodies are heartshaped
• They have long spinous
processes that point
sharply downward
• From the side, thoracic
vertebrae look like giraffe’s
head, this is what one can
use to identify these
vertebrae as thoracic
vertebrae
Lumbar Vertebrae
• The 5 lumbar vertebrae
are the sturdiest of the
vertebrae since most of
the stress on the
vertebral column occurs
in the lumbar region
Lumbar vertebrae L1-L5
• Their bodies are
massive and
block like
• From the side, a
lumbar vertebrae
look like a moose
head – this is
what one can use
to identify these
vertebrae as
lumbar vertebrae
Sacrum
• The sacrum is formed by
the fusion of 5 vertebrae
• Superiorly, it articulates
with L5
• Inferiorly, it articulates
with the coccyx (tail
bone)
Sacrum
• The sacrum forms
the posterior wall
of the pelvis
• The vertebrae
canal continues
inside the sacrum
as the sacral canal
Coccyx
• The coccyx is formed by
the fusion of 3 to 5
small, irregularly shaped
vertebrae
• It is the human
“tailbone”, a remnant of
the tail that other
vertebrate animals have
Identify the following vertebrae